Contributors
This report was compiled by the following members of IECS:
Dr. M. Elliott, Dr. N. V. Jones, Dr. D. S. Lewis, Dr. J. S. Pethick and Mr. D.
G. Symes,
with the technical assistance of:
M. P. Atkinson, C. R. Brickle, N. D. Cutts, S. C. Jacques, D. A. Meakin, B. J.
Murphy and C. M. Stapleton.
Additional information supplied by:
Dr. B. Denness, Bureau of Applied Sciences, Isle of Wight, and
Dr. J.Hardisty, Unico GeoSystems Ltd., University of Hull.
IECS wou ld like to acknowledge the help of Professor S. J. Lockwood in the
compiling of this report.
Filey Bay Environmental Statement
Institute of Estuarine and Coastal Studies University of Hull
December 1991
Acknowledgements:
This repost was commissioned by Filey Against Dredging, financed by Filey Town Council, plus voluntary
donations from local businesses, organisations and individuals and was supported by the World Wide Fund for
Nature UK.
© Copyright Filey Against Dredging – all rights reserved
This electronic copy of the report has been prepared by Optical Character Recognition of the original. The result
has been proof read and corrected as far as possible. Two species names substituted by more up to date names to
replace terms which are now synonyms.
The usual terms as regard academic copyright apply. Work in the report should be cited as the relevant Authors
name (1991) Filey Bay Environmental Statement - Institute of Estuarine and Coastal Studies University of
Hull, without mention of Filey Against Dredging.
1. INTRODUCTION
2. THE PHYSICAL ENVIRONMENT
2.1 Oceanography
2.1.1 Bathymetry
2.1.2 Temperature
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3
3
3
2 . 1 3 S alinity
2.1.4 Wave climate
2.1.4.1 Wave height
2.1.4.2 Wave period
2.1.4.3 Wave direction
2.1.4.4 Temporal trends
2.1.4.5 Wave refraction
2.1.5 Tidal currents
2.1.6 Residual currents
2.2 Littoral and Benthic Sediments
2.2.1 Geology
2.2.2 Surficial sediment distribution
2/.3 Sediment movement
2.2.3.1 Shore normal sediment movements
2.2.3.2 Longshore sediment movements
2.2.4 Sediment budgets
2.2.4.1 Storage
2.2.4.2 Outputs
2.2.4.3 Inputs
2.3 The coast
2.3.1 Cliff erosion
2.3.2 Human impact
2.3.2.1 Coastal defence works
2.3.3 Commercial extraction of beach sediments
2.4 Dredging Impacts
3. THE BIOLOGICAL ENVIRONMENT
3.1 Introduction
3.2 Plankton
3.3 Filey Bay - the Biology and Sediments of the Sea-bed
3.3.1 Introduction
3.3.2 Previous Studies
3.3.3 1991 Survey of the Soft-substratum Benthos
3.3.3.1 Introduction
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Institute of Estuarine & Coastal Studies
3.3.3.2 Methods
3.3.3.3 Results
a) Biological Sedimentary Habitat
b) Benthic Fauna
3.3.3.4 Discussion
3.3.4 Rocky-shore and subtidal hard substratum
3.3.5 Fauna of the Sandy Beach
3.4 Filey Brigg
3.4.1 Introduction
3.4.2 The Flora and Invertebrate Fauna
3.4.3 Small Fishes
3.5 Larger Fishes
3.5.1 Plaice
3.5.1.1 Introduction
3.5.1.2 The Plaice of Filey Bay
3.5.1.3 Spawning, distribution and movements of 0-group
plaice
3.5.1.4 Food
3.5.2 Sandeels
3.5.3 Exploitation of the fish stocks
3.6 Bird Ecology
3.6.1 Birds Associated with the Chalk Cliffs of the Flamborough
Headland
3.6.1.1 Introduction
3.6.1.2 Ecology
3.6.2 Birds Associated with Filey Brigg and the Beaches of Filey
Bay
3.7 Biological Summary
3.7.1 Overview of Biological Features
3.7.2 Impacts on the Biological Environment
3.7.3 Conclusions
4. THE SOCIO-ECONOMIC ENVIRONMENT
4.1 Introduction
4.1.1 Definition of Study Area
4.1.2 Aims and Structure
4.1.3 Method of Analysis
4.2 Description of the Area
4.2.1 General
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Institute of Estuarine & Coastal Studies
4.2.2 Administrative Structure
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4.2.3 Population Structure
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4.2.4 Settlement Structure
4.2.5 Employment Structure
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4.3 Tourism
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4.3.1 Introduction
4.3.2 National and Regional Trends
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4.3.3 Tourism Infrastructure: Visitor Accommodation
105
4.3.4 The Season
4.3.5 Tourism Infrastructure: Amenities
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4.3.6 Visitor Profile
108
4.3.7 Employment and Income Generation
4.3.7.1 General
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4.3.7.2 Employment
4.3.7.3 Expenditure
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4.3.8 Summary and Evaluation
4.4 Fisheries
4.4.1 Introduction
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4.4.2 Fishery Regulations
4.4.3 Filey
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4.4.3.1 The Fleet
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4.4.3.2 The Fisheries
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4.4.3.3 Employment and Earnings
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4.4.3.4 Evaluation
4.4.4 Bridlington
4.4.5 Scarborough
4.4.6 Overview
4.5 Assessment of Impacts
4.6 List of Consultees
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5. CONSERVATION
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5.1 Introduction
123
5.2 Nature Conservation
5.3 Landscape and Amenity Conservation
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5.4 Marine Protected Areas
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5.5 Summary and Conclusions
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6. CONCLUSIONS
7. REFERENCES
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129
Chapter 1: Introduction
1. INTRODUCTION
Filey Bay is one of the most important coastal sites in the British Isles. Its marine
biology represents a unique resource, both from conservation and the commercial
viewpoints. Its ornithological importance ranks it one of the outstanding seabird nesting
sites in Europe. It is an area of great scenic beauty – contained between the magnificent
headland of Flamborough and the unique Filey Brigg (fig 1.1), the bay is small enough
to be encompassed in a single view yet large enough to be imposing. Its coastal
geomorphology and oceanography are complex and provide one of the most interesting
examples of marine hydrodynamics on the British coast. And finally, because of the
special qualities of landscape and biology, the area has become an important tourist
attraction, an activity on which the economy of the region is now largely dependent.
Yet despite this wealth of interest there is no single source of information which
encompasses the whole of the Filey Bay environment and assesses its importance.
Although much work has been done, principally on the marine biology of the area, this
has been published in specialised journals and reports and is not widely available. As a
result, the complexity of interaction between physical, biological and human factors in
Filey Bay are not well defined.
This lack of coherence and interaction among the many studies of Filey Bay is of the
greatest importance at the moment, when pressures of many sorts exist in Britain to
exploit marine and coastal resources. The sensitivity of Filey Bay to such pressures
has never been adequately investigated, although it has long been intuitively recognised
that this environment is especially vulnerable. The present report, commissioned by the
local inhabitants of the area, is an attempt to redress this imbalance.
Th e repo rt brings together a wid e range of inform ation, both published and
unpublished, on the physical, biological and socio-economic environment of Filey Bay.
To th is already large amount of data it adds new inform ation on the physical
oceanography, coastal geomorphology and marine biology of the area – information
specifically collected and analysed for this report. This body of information thus
provides the first coherent study of the Filey Bay environment. It is intended to act as
an environmental statement to which reference can be made both generally, in order to
support the intuitive concept of Filey Bay's environmental sensitivity or, more
specifically, as a source of information when considering the possible effects of the
many environmental pressures which have been, and will continue to be, placed on this
unique resource.
1
Chapter 2: The Physical Environment
2. THE PHYSICAL ENVIRONMENT
2.1 Oceanography
Although Filey Bay appears to occupy a minor position on the eastern seaboard of the
British Isles, it occupies a critical position in the North Sea which gives its marine and
coastal environment a central, and indeed unique, importance. This unique position is
mainly due to the fact that the Bay straddles a discontinuity between the deep waters of
the northern North Sea and the shallow waters of the south. This change in depth is
itself responsible for a series of other oceanographical demarcations including
temperature, salinity and currents. Such changes in the physical environment are
followed by those in the biological activity of the area and Filey Bay again occupies a
key biological position on the east coast of Britain as will be demonstrated in later
sections of this report. Thus the complex spatial and temporal fluctuations in the
physical characteristics of Filey Bay and its surrounding sea must be understood before
any appreciation of its importance to animals, birds and humans can be formed.
2.1.1 Bathymetry
Fig 2.1 shows a generalised map of the bathymetry of the North Sea. The 50m depth
contour is taken as a critical demarcator between the deeper waters of the northern
North Sea and the shallower waters of the south. The critical contour runs, almost
linearly, from Flamborough Head in a north easterly direction towards the Kattegat
with the exception of two major southerly extensions of the Silver Pit and the Clay
Deep. This bathymetry is a result of glacier movements and deposition during the
Quaternary Period.
2.1.2 Temperature
The water temperatures of the Filey Bay sea region are profoundly influenced by the
bathymetry outlined in the previous section. In the deeper waters of the northern North
Sea tidal currents are relatively weak and this together with the greater mass of water
means that mixing between bottom and surface layers of water does not take place as
efficiently as it does in the higher tidal currents and shallow waters to the south. This
lack of mixing to the north of Flamborough means that during summer, when surface
waters become heated by insolation, the bottom layers remain cool — a layering effect
not exh ib ited in waters to the south. Fig 2.2a shows that the average bottom
temperatures in July are 10°C to the north of Flamborough and 15°C to the south. The
difference between bottom and surface temperatures in the northern waters (fig 2.2b)
3
Chapter 2: The Physical Environment
may be as much as 10°C in summer compared to only 1°C in the south. These dramatic
changes in temperature between surface and bottom waters and between north and
south constitute one of the most important oceanographical 'fronts' in the North Sea.
This front may often be seen as a marked line of sea fog or Haar running eastwards
from Flamborough, or as a line of debris on the sea surface, indicting that the
temperature differences are responsible for changes in the currents in this area of the
North Sea as described below (section 2.1.6).
2.1.3 Salinity
Figs 2.3 a to d show that, unlike the temperature differences between the bottom and
surface of the Filey Bay sea region, salinities do not exhibit any marked depth gradient
nor is there any marked difference between summer and winter salinity. A slight
northerly movement of the 34.4% isohaline is indicated due to the smaller effect of
north Atlantic water on the North Sea during the summer months but, in general
salinities in the Filey sea may be regarded as constant around the 34.4% level.
2.1.4 Wave climate
Perhaps the most important single factor affecting the physical and biological
characteristics of Filey Bay is the wave climate. Wave energy in this exposed area of the
North Sea coast is extremely high compared to areas further south, for example, the 50
year maximum deep water wave height, predicted to be 20m by MAFF (MAFF,
1981), rapidly decreases to only 10m south of Spurn Point. This high wave energy
regime causes movements of bottom sediments and erosion of the coastline, controls
the habitat and movement of marine organisms and plays an important part in the lives
of the human populations of the area. Yet despite the vital importance of waves to the
region there are no long term wave records from the Bay. A 17 month record has
recently been obtained from a wave rider buoy off Flamborough (Clayson, & Ewing,
1990) and these data have proved invaluable in the present study but this record is short
and unrepresentative. The only source of long term wave data is from the Dowsing
Light Vessel, some 90km south of Filey Bay, which has maintained a Shipborne Wave
Recorder since 1970 (Bacon, 1989). These two sources of wave data for the Filey Bay
area have been analysed by (Denness, 1991) (see Appendix A) and need only be briefly
summarised here.
2.1.4.1 Wave height
The probability density for waves recorded at the Dowsing Light Vessel is shown in fig
2.4. The 1 year significant wave height is shown to be 6.2m while the 50 year
6
Chapter 2: The Physical Environment
significant wave height is 8.5m. (cf the maximum wave height predicted by MAFF in
sectio n 2.4.1 above) . Fig 2. 5 taken from (Denness, 1991) shows that the
Flamborough significant wave heights are 10% greater than those at Dowsing
indicating that the 1 year return interval here may be 6.05m while the 50 year wave is
put at 8.88m by (Denness, 1991).
2.1.4.2 Wave period
The relationship between significant wave height and wave period for the Dowsing
wave data set is shown in fig 2.6. Wave periods as long as 10 sec are associated with
the highest waves (50 year return interval) while the mean period for waves at the
Dowsing is 4.4sec.
2.1.4.3 Wave direction
Th e relationship between wave d irection and wave height is essential to an
understanding of the impact of waves in the nearshore zone. This relationship is
shown for the Flamborough record as fig 2.7 (Denness, 1991). The maximum
significant wave heights are from the north to north-north-east (0° - 22'N) while
minimum heights are associated with directions from the SSW (205°N). A secondary
peak in wave height is, however, indicated as occurring from the SE (135°N) as may
be seen more clearly in the wave rose (fig 2.8).
These results may be contrasted with those for the Holderness coast on which waves
from the NE (45°N) provide maximum significant wave heights.
2.1.4.4 Temporal trends
(Denness, 1991) provides an interesting analysis of the trends in wave height over the
period 1970-85 as shown by the Dowsing wave data set. Fig 2.9 shows the results of
this analysis, the period 1976-1978 appears to have experienced a marked decrease in
the winter wave heights, while the period 1978-1981 experienced an increase. Thus
the mean January significant height decreases from a constant 4m in the period 1970-75
to 3.2m in the period 1976-78 and increases to almost 5m in the succeeding 3 year
period. This change in wave characteristics does not appear to be part of any secular
change in wave climate but it does indicate the dangers of extrapolating short term wave
records.
9
Chapter 2: The Physical Environment
2.1.4.5 Wave refraction
The refraction of deep water waves as they approach the shore sets up energy gradients
which cause sediment movement and result in changes in coastal and nearshore
morphology. Wave refraction in Filey Bay has not previously been studied and
consequently it was essential to provide a series of model predictions for this study so as
to allow a basic understanding of this important aspect of the wave climate of the Bay.
Using a refraction model developed by IECS and deep water wave data from theFlamborough and Dowsing wave recorders, predictions of the refraction patterns for
the four most important deep water wave approach angles were produced. These were
Wave return Deep water
interval
direction
Hs(m)
T(sec)
1
0
4.9
8.8
1
45
4.2
7
1
90
3.5
7
1
135
3.4
5
50
0
9.0
9
50
45
7.0
7
50
90
6.0
7
50
135
5.0
5
Table 2.1: Wave parameters used in refraction modelling.
0º(N),45º(NE),90º(E) and 135º(SE). The model runs were repeated using both 1 year and
50 year return interval wave characteristics and are listed in Table 2.1.
The bathymetry used in these model runs was taken from Admiralty Charts which had
been modified using field bathymetric data collected by IECS. The results of the model
predictions are shown graphically in figs 2.10 to 2.17. Although the results of the
modelling were primarily intended to produce quantitative data on wave approach
angles which themselves would form part of the sediment transport modellin g
procedures described below (section 2.2.3), these refraction diagrams do demonstrate
13
Chapter 2: The Physical Environment
some interesting qualitative generalisations to be made concerning the wave energy
regime within Filey Bay.
The results of the 1 year wave modelling indicate that, during northerly wave events (fig
2.10), wave refraction within Filey Bay results in two marked wave foci. These foci
concentrate wave energy at two points on the coastline of the Bay : at Speeton and
Reighton, and it is interesting to note that it is here that the most pronounced cliff
erosion rates are recorded (see section 2.3.1 below). Fig 2.10 also demonstrates the
pronounced wave shadow effect produced by the Brigg on the coastline north of
Hunmanby. This is not true of the 50 year wave events, however, when the longer
period waves are able to refract around the Brigg and cause extensive erosion along the
Filey foreshore. Such an event was recorded during the, now infamous, storm of 1
February 1953 when floods caused extensive damage along the whole coastline of the
southern North Sea. During this event the following record was kept by C Harris (Hull
University):
'Although, normally, the Nase and the Brigg afford good protection from northerly
storms, ones of particular severity do cause damage. The devastating storm of 31
January and 1 February 1953, when northerly winds blew with gusts up to 80 m.p.h.
caused considerable damage at Filey North. The Sailing Club house, which was then
on the Coble Landing, was damaged after the sea had removed the top of the sea wall
and the heavy pounding of the sea against the cliffs caused slips and falls between the
Landing and the Carr Nase.'
In contrast, deep water waves approaching from the north east do not result in any
marked foci. The implication is that the bathymetry of the Bay is such that the crests of
north easterly waves parallel the nearshore topography. This may be because the Bay
topography has adjusted to these particular waves in which case the contrast with the
northerly wave refraction pattern is especially significant.
The refraction pattern in the Bay produced by deep water easterly waves (figs 2.12 and
2.16) shows that two wave foci occur: one in the extreme north of the Bay at Filey
Sands, the other again sited at Reighton. These two foci may be expected to produce
marked upper beach erosion during easterly storms and this is commonly observed at
Filey Sands. The focus at Reighton reinforces the conclusion drawn above that the
rapid cliff erosion experienced here is due to wave energy concentrations both during
easterly and northerly wave events.
16
Chapter 2: The Physical Environment
Refraction patterns developed by waves approaching from the south east show a weak
focus at Hunmanby and an area of energy dissipation south of that. The energy levels for
these SE waves are low and the effect of such coastal gradients will not be marked.
Nevertheless during such wave events the predictions derived from the model would
indicate that erosion of the beach will occur in the Hunmanby area and that this eroded
material will be transported northwards to accrete on the Muston Sands area.
2.1.5 Tidal currents
Figs 2.18 a to c show the tidal currents for three stations, one some 10 km north east of
Flamborough, (A) the second 1km east of Flamborough (B) and the third 1km off
Bridlington harbour (C). Tidal current directions in the open sea flow from north to
south during the last half of the flood tide and first half of the ebb reversing to a south
north direction at half tide. In the nearshore off Flamborough and Bridlington,
however, tidal currents reverse one hour after high water so that for two hours after that
the flows around the headland are in the opposite direction to those further seawards
(fig 2.18a).
The magnitude of the current velocities varies considerably between the three stations,
sprin g tide velocities of 3.25kt (1.65msec -1 ) are experienced immediately off
Flamborough reducing to 2.5kt (1.27msec-1) in the open sea and to 1.01kt (1.65msec-1)
off Bridlington.
Figs 2.19 and 2.20 illustrate the spatial distribution of tidal currents on spring and neap
tides. The spring flood tide current field results in clockwise gyres in Bridlington Bay,
centred over the Smithic Sands, and in Filey Bay. Neap tides produce clockwise gyres in
both bays. The residual currents produced by these tidal systems are discussed
below.
2.1.6 Residual currents
Two types of residual currents are describe here, the tidal residuals, that is the net water
movement over a full semi-diurnal tidal cycle and the seasonal residual currents which
vary between winter and sum mer, m ainly due to the presence or absence of
thermoclines.
Tidal residuals are shown in figs 2.21 and 2.22. During spring tides the residual
velocities flow north to south around Flamborough while during neap tides the opposite
direction applies.
17
Chapter 2: The Physical Environment
Seasonal variations in residual currents are shown in fig 2.23. In winter, the water
column in the North Sea is homothermai and the flows are affected mainly by the input of
Atlantic waters from the north. This slow mass movement of water divides into two
streams off Flamborough. The northern stream flows north westwards while the
southern stream flows south past Flamborough and enters an anti-clockwise gyre
situated off the Lincolnshire coast (Harding, & Nichols, 1987). These winter currents are
extremely slow averaging only 0.023 m sec-1 to 0.035m sec-1. In summer a more
complicated current system is set up due to the thermocline north of Flamborough. The
colder bottom water in the north flows south and west past Flamborough (averaging
0.10m sec-1) while the surface drift flows north and east (averaging 0.07m sec-1): an
offshore movement which sets up a compensatory bottom flow upwelling along the
coast.
2.2 Littoral and Benthic Sediments
The surface sediments of Filey Bay both sub-tidal and inter-tidal, are crucial to its
stability, its biological importance and, not least, its tourist industry. As such, and
account the distribution and movement of the sediments in the Bay occupy a central
position in the present report. It is hardly surprising that most of the information
concerning these sediments refers to the inter-tidal areas and that benthic sediments
have received little attention in the past. Recently, however, the British Geological
Survey have mapped sediment distributions in the Bay and this work has been
supplemented with a field survey carried out specifically for the present research. In
addition, the work described above on wave refraction and current prediction has been
used to investigate the movement of sediments in and around the Filey Bay area and the
results of this work form a major part of the outline presented here.
2 .2.1 Ge ol og y
The solid geology of Filey Bay is straightforward. In the north of the area, that is north of
Reighton, Jurassic rocks underlie the area, in the south Cretaceaous rocks form the
massive headland of Flamborough. The Jurassic sequence is as follows: Filey Brigg
itself is composed of Corallian grits and limestones; south of the Brigg, Kimmeridge
Clays lie beneath the Devensian glacial deposits although, significantly, these clays do
not begin until some distance south of the coastal 'angle' (GR12508160) which
characterises the northern arm of Filey Bay. Finally, Lower Greensand and Speeton
Clays underlie the coast from Hunmanby to Speeton forming the cliffs between
Speeton and the Brigg and forming the sea bed surface in the Bay. Above these
Jurassic rocks lie the glacial tills of the Wolstonian and Devensian periods. The depth of
these deposits has not been determined.
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Chapter 2: The Physical Environment
The Upper Cretaceous Chalk which forms Bempton Cliffs and Flamborough Head is
exposed first as an inter-tidal abrasion platform and then on the sea bed for some 500m to
1000m offshore. The nearshore sea bed here has been described by (Wood, 1988) as
predominantly rocky with substantial chalk outcrops forming pronounced terraces
defined by steep scarp edges. These scarp edges are 0.5m high to the south of
Flamborough and 1.0m high to the north and east. The terraces are broken by deep
gullies running at right angles to the coastline.
2.2.2 Surficial sediment distribution
The littoral and benthic sediments, which lie over the solid rocks described above, are
shown in figs 2.24 and 2.25. Fig 2.24 compiled by the British Geological Survey
shows that most of the seabed is overlain by a gravelly sand grading to a sandy gravel to
the east of Flamborough Head. In the centre of the Bay an area of muddy sand is shown
and immediately south of the Brigg lies a distinctive patch of sandy gravel.
The benthic sediment around Flamborough may be described in more detail. (Wood,
1988) describes a continuous unbroken expanse of fine sand close inshore and
extending from Speeton to Buckton Cliffs. Around the rest of the headland this
sediment plain lies further offshore and only pockets of sand and silty gravels cover the
chalk abrasion platform in the nearshore. Fig 2.25 indicates that a continuous band of
fine sand extends around Flamborough and south into Bridlington Bay. This fine sand
grades seawards into a band of coarser sand running parallel to it and forming the
Smithic Sand in Bridlington Bay.
Fig 2.26 shows the results of a field survey by IECS in the area. Bottom sediment
samples were obtained using a standard van Veen grab from 21 stations located
b etween Bridlington and Filey Brigg. Samples were analysed for grain size
distributions using a wet sieve methodology. The distribution of the mean grain size
(fig 2.26) is similar to that suggested by the generalised size classes shown in Fig 2.24. In
particular, the distinctive patch of gravelly sand in the centre of Filey Bay is shown to
have a mean grain size of -0.86Ø (1.9mm), while a littoral and nearshore band of fine
sand is shown running between Bridlington and Filey. The mean grain size of this sand
coarsens slightly between Bridlington and Reighton decreasing from 2.01Ø
(0.25mm to 0.3mm). At Hunmanby a finer grain size is noted (2.5Ø) which then
coarsens towards Filey itself where the mean grain size is 1.950. Lastly, a marked
muddy sand area (mean grain size 3.3Ø or 0.110mm) is noted 1km north of the
Bempton Cliffs.
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Chapter 2: The Physical Environment
2.2.3 Sediment movement
The complex movement of sediments in Filey Bay have been analysed using computer
modelling techniques supported by wave data obtained from the Flamborough and
Dowsing recorders (Denness, 1991), tidal data from the Holderness coast tidal model
(Halcrow & Partners (Civil Engineers), 1986) and sediment grain size analyses from
published sources and from field sampling undertaken specifically for this study (see
section 2.2.2 above). Using these data sources an attempt was made to pred ict
whether sediment transport of varying grain sizes occurred in the Bay and, further, to
predict the quantities of sand involved in such movement.
The critical threshold for sediment movement on the sea bed or along the inter-tidal
zone depends on two factors: the strength of the wave- (and, although to a lesser
extent, tidal-) driven currents and the size of the sediment grains. Wave driven currents
are related to the size of wave at any given time and therefore any predictions of
movement must take into account the temporal variability in wave characteristics. Thus
sediment grains of a given size which will remain stationary under a wave with a return
interval of 1 year may be transported by the 2 year wave. In his report (Denness,
1991) suggests that the 50 year wave may be proposed as providing a reasonable
compromise between the low magnitude, high temporal frequency events and the high
magnitude low frequency wave events. Accordingly the 50 year waves were chosen
here as providing an indication of the potential mobility of sediments in Filey Bay.
Again following (Denness, 1991), the direction of the 50 year waves used in the
analysis was as shown in table 2.2:
Table 2.2: 50 year return interval wave characteristics (after (Denness, 1991)).
Wave Direction
Wave Height
(m)
Case I
N
9
9
Case II
NE
7
7
Case III
E
6
7
Case IV
SE
5
5
Wave Period
(s)
Using these wave characteristics sediment movement was predicted under two types of
wave induced currents:
a. Shore normal currents
b. Longshore currents
28
Chapter 2: The Physical Environment
2.2.3.1 Shore normal sediment movements
The 50 year northerly wave in Filey Bay with a significant wave height of 9 m. and a
period of 9 sec. is found to break in approximately 10 m. water depth. At this point
current velocities of >3 m sec-1 are predicted and these extremely high velocities are
capable of moving even the coarsest sediment (small boulders with diameters of 0.15
m. -0.20 m.) found in the Bay. The wave heights and, consequently, wave driven
currents decrease in magnitude as wave approach angles move clockwise from
northerly towards the south east (Table 2.2). Thus the south easterly 50 year wave
with a significant wave height of 5 m. generates a current of 1.9 m. sec-1 and is capable of
moving gravels with a diameter of 0.05 m..
The shore-normal wave currents increase in magnitude towards the break point and
decline thereafter towards the shore (fig 2.27). This means that coarse material will be
moved up to the break point during the 50 year storm where it will be deposited while
finer material moves on towards the shore. Waves of lower return intervals may then
redistribute the finer sediments, in particular by transporting seawards the finer grained
sands which were moved into the nearshore during the 50 year storm. The coarser
gravel and boulder fractions however are not re-entrained during these lower energy
wave events and thus remain where they were deposited at around the 10m depth
contour. This is reflected in the sediment distribution map (fig 2.26) which indicates
larger proportions of gravels in the outer bay sediments than in the nearshore zones,
which are predominantly sandy. The distinctive area of coarse gravels lacking the high
percentage of sand characteristic of the majority of outer bay sediments immediately
south of the Brigg mentioned above (section 2.2.1) presents a more difficult problem of
interpretation. If reference is made to the wave refraction diagram (fig 2.14) for the 50
year northerly wave, it will be seen that this region of the Bay is characterised by a
wave focus which in turn means that higher waves are experienced along the northerly
wave track immediately east of the Brigg than elsewhere. Calculations indicate that
waves along this track will break in 15 m. of water compared to a 10 m. breaking depth
elsewhere and this may lead to the build up of gravels further seaward here than in
other areas of the Bay. This may also be the explanation for the marked 'bulge' in the 15
m. bathymetric contour at this point (see fig 2.28).
The volumes of material moved by the shore-normal currents have been predicted by
Hardisty ( see figs 2.29 a-d). His work indicates that the volume of transported
sediment increases along the wave track (or wave orthogonal) up to the break point .
Such an increase in transport means that sea bed sediments seawards of the breakpoint
must be eroded in order to supply the increasing demand and this eroded sediment is
29
Chapter 2: The Physical Environment
carried towards the breakpoint. Shorewards of the breakpoint the sediment transport rate
decreases - and this in turn must lead to the deposition of the sediment load as
shown in figure 2.30. The maximum rate of transport seawards of the breakpoint
under a 50 year northerly wave is 35 m3 m-1 hour-1: a rate which, if extrapolated over
the whole length of Filey Bay for a 3 hour wave duration, would mean that 74,000 m3 of
sediment would be eroded from the outer bay and deposited in the nearshore.
Although such a volume of sediment seems large it represents less than 1 cm. of
deposition over the whole nearshore zone of the Bay (assuming this to be 7 km. x 1.5
km. in area).
2.2.3.2 Longshore sediment movements
Sediment movement parallel to the shoreline takes place when waves approach the
shore at an angle. This forces water to move in a uni-directional current along the
shore, a current which increases with wave height and with the angle between wave
and shoreline. Calculations of wave-induced longshore transport have been carried out
for the 50 year northerly and north easterly waves. The calculations include prediction of
wave height and angle at the shore due to refraction and shoaling transformations,
prediction of the wave energy gradient along the shore and finally the wave induced
current velocities and consequent transport rate.
Figs 2.31 and 2.32 show the variations in such longshore transport along the length of
Filey Bay during the north and north easterly 50 year waves. The figures also indicate
the predicted areas of erosion and deposition which will occur as a result of these
movements of sediment. The northerly wave results in southerly transport along the
length of the Bay (fig 2.31). The rate of such southerly transport is seen to increase
gradually southwards from the Coble Landing until Reighton Cliffs, when it begins to
decrease towards Flamborough Head. This results in the erosion of the nearshore zone
sediments in the north of the Bay, but deposition south of Reighton. Of great
importance here is the fact that, although most of the eroded sediment from the northern
Bay is redeposited in the south, the sediment balance is not complete and some
sediment escapes from Filey Bay around Flamborough Head. The predicted amount of
this 'lost' sediment is not great - amounting to 6.1 m3 sec-1 or 65,700 m3 during the 3
hour duration of the 50 year wave event - but the loss of this material from the Bay is
central to its long term stability and will be discussed in the following section.
In contrast to the northerly waves, the sediment transport produced by the north
easterly waves (fig 2.32) does not result in sediment losses to Filey Bay. The diagram
shows that large volumes of sediment are eroded from the northern nearshore zone but
34
Chapter 2: The Physical Environment
that this is carried southwards and redeposited between Hunmanby and Reighton. In
the southern arm of the Bay erosion again occurs but this material is carried northwards
and is redeposited between Speeton and Reighton. The volumes of sediment moved in
the southern Bay during a north easterly storm are far lower than those in the north (a
maximum of 10 m3 sec-1 in the south compared to >50 m3 sec-1 in the north) but neither
movement results in losses to the Bay as a whole.
Although sediment transport modelling has not been performed for the two remaining 50
year wave directions specified by (Denness, 1991) - that is the easterly and south
easterly waves - it is clear from the wave refraction diagrams (fig 2.16 and 2.17) that
neither wave will result in sediment losses from the Bay but merely in a redistribution of
sediment volumes within the Bay.
2.2.4 Sediment budgets
Perhaps the most important issue addressed in the present report concerns the long term
stability of the marine and coastal sediments of Filey Bay. In order to predict the long
term sediment balance, the results of the sediment transport calculations outlined above
have been incorporated in a sediment budget which defines both inputs and outputs of
sediment and relates these to the store of sediment held within the Bay. The budget
may be considered as consisting of three elements:
a. Storage.
b. Outputs.
c. Inputs
2.2.4.1 Storage
The total volume of sand stored at any one time in Filey Bay is difficult to compute
since little accurate data on sediment depths is available. Approximate volumes may be
calculated by assuming that the depth of sediment in the nearshore (i.e. in depths of <5
m.) averages 1 m., while that in the offshore (i.e. in depths between 5 and 15 m.)
averages 0.25 m.. Such assumptions, based upon the scanty data available, indicate
that nearshore sediment store amounts to 3 x 106 m3 while the offshore zone contains
9.0 x 106 m3. The total sediment store of the Bay may therefore be tentatively placed at
12.0 x 106 m3.
2.2.4.2 Outputs
The results of the refraction modelling and sediment transport predictions described in
the previous section show that sediment is only lost from the Bay under northerly
38
Chapter 2: The Physical Environment
waves and that, during a single 50 year wave event this loss amounts to less than
100,000 m3.
The key issue here is the amount of southerly moving sediment which passes the most
southerly reach of Filey Bay and therefore moves around Flamborough Head. (Wood,
1988) describes the continuous band of sandy sediment which borders the seaward
edge of the rock platforms around Flamborough. This sediment band was identified from
the field survey results as consisting of medium to fine sand and showed a
decreasing grain size from Bridlington to Reighton (see section 2.2.2 above)
commensurate with a southerly moving sediment pathway. This band of sediment
appears, therefore, to follow the sediment transport pathway from Filey Bay into
Bridlington Bay, a pathways only active during northerly wave events. The amount of
sand entering this pathway is determined by the wave energy and wave approach angle
along the nearshore zone south of Speeton - a reach which may be likened to a 'gate'
leading out of Filey Bay.
Although the volume of sand moved out of this gate and along the southerly trending
pathway is predicted to be 65,700 m 3 during the single 50 year wave event, the
calculations given above do not allow a prediction of the volumes moved over a longer
period of time. To allow such a prediction it was necessary to calculate the volume of
southerly transport for a number of shorter return interval wave events along this
southern reach of the Bay. Wave return intervals of 1, 10 and 25 years were used and
incorporated with the 50 year predictions. Fig 2.33 shows the results of this work,
which allows the total volume of sediment transport to be calculated over the whole of a
50 year period. The resultant total 50 year transport volum e of 1,900,000 m 3
represents the total loss of sand from Filey Bay during this period. Although the
movement of sediment is episodic rather than continuous, being driven only by
northerly waves, it may be more useful to consider the yearly average loss from the
Bay as:
2x106/50 = 40,000 m3 yr-1
The work of Hardisty (Appendix B) suggests that no losses of sediment are likely via
shore normal transport pathways. During northerly long return interval storms,
sediment is moved onshore from depths less than 22m but no material is moved
seaward of this depth or is involved in a seaward transport pathway. In this context, it is
interesting to note the correspondence between the onshore transport rate predicted by
Hardisty during the 50 year event (74,000 m3 ) and that calculated above for the loss
of sediment during the same storm (65,700 m3 ), figures which, given the error
39
Chapter 2: The Physical Environment
terms in such model predictions, may be regarded as identical.
It appears from the above discussion that average losses of sand from Filey are in the
order of 40,000m3 per year when a long term budget is considered. This material is
shown to be derived from the seabed in the Bay, in water depths less than 22m.. The
finer fraction is moved towards the shore where it is carried south around Flamborough
Head. It is clear from these figures that the entire store of sediment in the Bay would
be removed in 300 years unless these sediment losses were made good by sediment
inputs into the Bay. There is no indication in any of the documentary or cartographic
records of any such long term degradation of the Filey Bay sediment store. Although
short term changes in shore sediments associated with storms, and medium term
decreases associated with its commercial exploitation, have been noted, there is no
evidence for the loss of such a significant proportion of the sediments of the Bay as
predicted here. Instead an assumption of long term sediment stability may be put
forward, an assumption which requires that a constant input of sediment into Filey Bay
is identified.
2.2.4.3 Inputs
Cliff erosion is an obvious source of sediment inputs into Filey Bay. The rate of such
erosion is, however, extremely small compared to the volume of sediment lost by
longshore transport. Best estimates for cliff erosion indicate that it may contribute less
than 10,000 m3 of sand sized material per year to the nearshore zone.
The work of Hardisty (Appendix B) shows that no sediment transport may be expected
to enter the Bay from seaward since the 50 year wave fails to move sediment at depths
greater than 22 m.
The only remaining source of sediment must be a longshore movement of sand from
the south around Flamborough Head. Such a movement cannot be sustained by wave
action since the south easterly and southerly waves although they are capable of moving
sediment from Holderness to Bridlington Bay are of insufficient energy to carry this
around Flamborough Head and this material is therefore deposited in Bridlington Bay,
probably contributing to the Smithic Sand deposit. The tidal currents which flow
around Flamborough are, however, extremely powerful (see Section 2.1.5 above) and
calculations indicate that these are capable of entraining and transporting sediment from
the Smithic Sand around Flamborough to be deposited in Filey Bay.
41
Chapter 2: The Physical Environment
Data from tidal model predictions show that a northerly tidal residual current is present on
spring tides while a southerly residual is present of neap tides. The magnitude of the
spring tide residual current (0.11 m sec-1) is slightly greater than that on the ebb (0.09 m
sec-1 ). Using a Bagnold-type cubic relationship between transport and velocity
and assuming that sediment entrainment is wave driven gives the results shown in table
2.3.
Table 2.3: Sediment transport rates produced by spring and neap tides.
Spring tide
0.11
Transport per
Transport Transport rate Transport rate
per tide.
over 200m year (assuming
m 3 m - ls ec - 1
[ K(v)3] (3600 x 12.4) wide zone per 360 springs, 360
tide
neaps)
K =0 .0 25
1.48
288.0
103, 680
0.000033
(northerly)
Neap tide
(southerly)
0.09
0.000018
Residual
velocity
m sec-1
Net transport
(+ve northerly)
=
–
–
0.813
162.7
+0.667
+125.3
58, 576
+45, 104
_
While such results can be regarded only as first approximations given the degree of
precision of the data available, they may be regarded as correct to within an order of
magnitude and thus give an indication that total input of sediment into Filey Bay due to
tidal currents is sufficient to balance the sediment budget over a long time period.
The results of the sediment budget are that losses of 40,000 m3 per year to the south
via Flamborough Head are balanced by cliff inputs and by northerly tidal current
transport of sediments from Bridlington Bay into Filey Bay. The absolute quantities of
sediment involved in these movements are small when compared with those for the
Holderness coast immediately to the south which total 250,000 m3 per year. They are not
inconsiderable, however, when compared to the total volume of sediment stored in Filey
Bay, since the total output of sediment from the Bay would, if not replaced by inputs,
result in total loss of sediment within 3 centuries. The conclusion which may be
reached as a result of the work is that Filey Bay enjoys a long term sediment stability but
that this stability depends on the continued movement of relatively small amounts of
sediment across Flamborough Head. Any disruption of this sediment pathway could
42
Chapter 2: The Physical Environment
mean the rapid loss of marine and coastal sediment from the Bay leading, among other
things, to increases in wave energy at the shore and accelerated cliff erosion.
2.3 The coast
2.3.1 Cliff erosion
Cliff erosion in Filey Bay, although not as severe as in Holderness, nevertheless plays an
important part in the natural dynamics of the Bay as well as providing a major
problem for residents and visitors. Table 2.4 shows the recent erosion rate at 7 points
around the Bay, measured from the erosion posts set out by Filey and Bridlington
Council in 1952.
Table 2.4 : Annual cliff erosion rates
Post no
erosion Annual
rate (m)
Position
1A
Reighton Gap
1.3
1
Reighton Gap
0.15
2
Hunmanby Gap
0.14
3
Primrose Valley
4
Muston
0.11
5
Lifeboat House
0.033
6
Horn Dale
0.033
nil
Average erosion rate
0.25m per year
These figures can be compared with those quoted by (Dosser, 1966) in a report on the
effect of beach sand abstraction prepared for Bridlington RDC. Dosser notes that the
erosion rate for Filey Bay during the period 1850-1928 was "about 6 inches per year"
or 0.15m per year. During the period 1928 - 1964 this increased to 1.0 feet or 0.3m
per year. This latter figure is slightly higher than the figures quoted in table 2.4 above but
Dosser was using only the Bridlington RDC erosion posts sited in Filey Bay while Table
2.4 also uses posts placed by the Filey Council. Dosser attributes the difference in
erosion rates in the two periods to the increase in abstraction of beach material in the
period 1928-1964.
The contribution of the Filey Bay cliff erosion to the beach sediment store can be
calculated using the average erosion rate of 0.25m per year. The total length of
exposed glacial till cliff in Filey Bay is 5.6km. and the average height of the cliffs is
43
Chapter 2: The Physical Environment
41m. An erosion rate of 0.25m per year would therefore produce 57,400m3 of debris . Of
this material only 10% is of a size sufficiently large (>300μm) to be retained on the
beach, any material less than 300 μm will be transported seawards as suspended load.
Thus the total amount of material retained on the beach each year as a result of cliff
erosion is 5,740m 3. Given an average density of 1600kg m -3 for this material, a
volume of 5,740 m3 would have a weight of 9184 tonnes — slightly greater than that
calculated by (Dosser, 1966) who estimated that some 7200 tonnes of beach sized
material would enter the beach each year.
The average figures for cliff erosion given above, conceal a considerable amount of
variability in the rates along the Filey Bay coastline. Most erosion is concentrated in the
Reighton area where (Harris, 1966) reported 70yds (64m) of erosion between 1844
and 1962. This is an average rate of 0.5m per year - considerably higher than the
average figures quoted above. The lack of erosion in the north of Filey Bay and the
higher rates towards Reighton are explained by the pattern of wave foci described in
section 2.1.4 and the pattern of sand accretion produced by north easterly waves as
described in section 2.2.3 above. The result of these factors is that the locally high
wave energy at Reighton is exacerbated by a decrease in beach thickness so that wave
attack of the cliff foot during storms is especially severe here.
2.3.2 Human impact
2.3.2.1 Coastal defence works
Coastal defence works in Filey Bay are absent on all maps and plans until the mid-19th
century. Filey foreshore itself in the 18th century consisted of a large slipped mass of
glac ia l t ill and unm etalled roads led down across this to the beach. Town
improvements between 1842 and 1856, a time when Filey was developing as a spa
town, included the first recorded sea wall when the cliff edge of the new marine parade
was protected from erosion by stone slabs. This protection ended at Carrgate in the
north and Martin's Ravine in the south and erosion continued in both these areas, so
that by 1880 some concern was being felt for a number of houses, built on the landslip
terrace north of Carr gate. In 1857 a bridge over the Church Ravine was washed away
and a series of landslips had caused the path to Carr Nase to be moved landwards. In
1880 a series of wooden pilings were installed to alleviate this erosion, but with little
success.
A new sea wall was therefore required and this was officially opened on 19 June 1894. It
ran from Church Ravine to Crescent Hill, a distance of 700m. Further north a
44
Chapter 2: The Physical Environment
wooden barrier was built to protect the Coble Landing below Pampletine Cliffs and
these were in need of constant repair over the next few decades. To the south, the
wooden pilings installed in 1880 were strengthened and remained in place until 1926. In
1930 a northerly extension to the stone sea wall was constructed to protect the
Pampletine and Coble Landing area so that by 1931 the whole of Filey frontage from
Crescent Hill to the Coble Landing was protected. A plan to extend the wall south to
replace the wooden piling defences which were by 1930 in a parlous state was put
forward but was not put into operation.
The storm of 1953 (see section 2.1.4.5 above) finally destroyed the southern wooden
defence works and within two weeks the plan to extend the sea wall along this
southerly section was resurrected and implemented in the following year.
The effect of the sea wall has, of course, been to afford Filey a measure of protection
which was badly needed; it has other implications of a less favourable nature however.
First the wall is reported to result in considerable scour at its toe. Although the
construction was well toed into the underling glacial till, this scour suggests that the
foreshore at this point is not in equilibrium and that it is only maintained in its present
position by the sea defences. Second, the presence of the wall has arrested sediment
movement in both directions along the coast exacerbating erosional forces at either end.
This is especially true of the northern end of the defence works where sand accretion is
extremely poor during easterly and south easterly waves compared with previous
centuries.
2.3.3 Commercial extraction of beach sediments
The commercial exploitation of sand and gravel from the beaches of Filey Bay has a
long and controversial history. Repeated attempts by individuals and companies have
been made over the past two centuries to acquire the rights to sand and gravel extraction
from the inter-tidal beach. Almost as frequently, the local authorities have ruled that
such extraction should either be prohibited or be contained so as to prevent accelerated
cliff erosion and loss of foreshore amenities. Thus in 1791, the Filey Enclosure Award
granted the taking of sand and gravel to the inhabitants of the township of Filey "
provided that no damage be done to the the foot of the cliff or the bounds of any of the
allotments hereafter set out by us". In 1853 an order prohibiting the taking of sand and
gravel from the foreshore in front of the town was made under the authority of the
Harbours Act of 1814. In 1904 the Filey Improvement Act made it an offence to
remove sand, gravel, shingle, rock and other materials from the seashore except by
consent of the Lord of the Manor under the Enclosure Act of 1791.
45
Chapter 2: The Physical Environment
Ownership of the rights of sand and gravel extraction has had a complex history.
Rights to the northern shoreline of the Bay, that is the shore within by the parishes of
Hunmanby, Muston and Filey was initially held by the Lord of the Manor, who
subsequently sold them during the early 20th century to commercial interests. The
rights to the shoreline of Reighton and Speeton were also initially held by the Lord of
the Manor who again sold them to a commercial company in 1939, although there was
some controversy here over the area over which this transfer of rights applied, in
particular the Speeton foreshore rights.
The commercial extraction of sand and gravel, as opposed to small scale extraction for
local purposes, thus began duirng the early 20th century and continued until the late
1960's. The amounts of material extracted were considerable. Messrs Toulsons, who
extracted material from the Reighton beach, are reported to have removed 25,000
tonnes per year (40, 000m3yr-1 ) during the period 1939-1969 – a total of 750,000
tonnes (1.2 million m3 ). This may be compared to the estimated loss of 40, 000 m3
yr-1 from Filey Bay due to natural causes and to the estimated 12 x 106 m3 of
unconsolidated sediment stored in Filey Bay at any one time.
These significant amounts of sediment removed by commercial companies appears,
from contemporary accounts, to have a serious effect on the cliff erosion rate and the
levels of sand on the beach. Witnesses in a case brought by one firm appealing against a
decision to prohibit further extraction of sand and gravel in 1955, commented on the
heavy cliff falls which had recently occurred and the deterioration in the beach. The
Harbour Engineer of the time stated that:
"There is no doubt that this beach has been denuded of sand and
that dangerous conditions have been created for the launching and
beaching of fishing vessels and the lifeboat. There is evidence of
heavy scour southwards along the beach as far as Reighton Gap at
least where excavation of sand for commercial purposes is,and has
been, taking place."(Kelly, 1956)
Such accounts indicate that the loss of 40,000m3 per year of material from the Filey
Bay beach zone was sufficient to create unstable conditions along the entire foreshore.
They confirm the conclusions of the sediment budget work discussed above in which the
gross inputs and outputs to the Bay are put at 40,000m3 per year, so that loss of a similar
amount by commercial exploitation, which will not be balanced by natural inputs
into the Bay, will necessarily result in a marked decrease in the total sediment store in
the Bay and the rapid increase in cliff erosion.
46
Chapter 2: The Physical Environment
2.4 Dredging Impacts
The three criteria adopted by Hydraulics Research Ltd in their assessment of dredging
impacts on the coast are as follows:
a) That the material to be removed is not mobile
b) That, if the material is mobile, it does not form part of an active transport path
c) That the removal of the material will not lead to an increase of more than 10% in the
nearshore wave regime.
These three criteria have been considered in detail by Hardisty as part of the present
programme of work. His results are set out in detail in Appendix B to the report and
need not be given in full here. The first two criteria have already been examined in the
foregoing sections of this report which have dealt with the mobility and the transport
pathways of sediment in Filey Bay. It is clear from this work that neither of these two
criteria are satisfied in the Bay. Sediment of all grain diameters is moved during the 50
year wave from all directions, with the exception of the coarsest gravels (D>0.02m)
lying in the north of the Bay which may not be moved by the 50 year wave approaching
from the south east.
Sediments eroded from the sea bed in water depths between 22 and 10m during the 50
year storms are transported towards the wave breakpoint. Inshore of this they
encounter the longshore currents which move the sediments in directions which vary
according to wave approach angles and wave foci. Thus all sediments within Filey Bay
form part of complex sediment transport pathways which, as shown above, result in
long term losses to the Bay of approximately 40,000m3 of sediment per year. This loss is
however, balanced by cliff erosion inputs and by the movement of sediment from
Bridlington Bay under the influence of the spring tide residual current.
The third criteria, that any dredging operation should not result in an increase in the
nearshore wave energy of more than 10% was addressed by Hardisty in his report. He
concludes that under an assumption that the removal of approximately 2m depth of
sediment from the sea bed by dredging operations would result in an increase of only
2% in the nearshore wave energy regime. Thus the third criteria is met according to
this analysis.
47
Chapter 2: The Physical Environment
The sensitivity of Filey Bay to slight changes in its sediment budget regime was well
demonstrated during the 1960's when quantities of beach sediment were taken from Filey
beaches by a commercial company (see section 2.3.3 above). The resultant cliff erosion
demonstrated the very rapid response time of the Bay even to to such limited
interference. Removal of sea bed sediment using present day dredging methods could
present a much more serious interference with the natural regime in Filey Bay. A
modern dredger, capable of extracting 3000 tonnes (2000m3) of sediment in a single
operation could, assuming a 24 hour turn round period, extract 0.5million m 3 of
sediment in a year. This represents 4% of the total sediment store in the bay and would
certainly be reflected in major morphological changes to the cliffs, foreshore and
seabed, since the work outlined above has demonstrated the interconnectivity between
seabed and foreshore sediments.
48
Chapter 3: The Biological Environment
3. THE BIOLOGICAL ENVIRONMENT
3.1 Introduction
A description of the condition of the shore and sea-bed is an integral part of any marine
environmental assessment. The types and abundance of animals which live in the
sediments (the benthic infauna) and the plants and animals which live on the sediments
and rock outcrops (the macroflora and epifauna) will reflect the environmental
conditions to which they are exposed. For example, polluting discharges will affect the
quality of the waters and sediment, and activities such as dredging and dredge-spoil
disposal will change the nature of the sea-bed.
Some organisms have the ability to withstand these changes whereas others are more
sensitive and thus will be removed in the early stages of any disturbances. In many
cases, the tolerant organisms will thrive under disturbed conditions especially when
sensitive species have been removed. Also, in addition to responding quickly to any
acute changes in the environmental conditions, the benthos (a term referring to animals
and plants living on or in the sea-bed) will integrate over time any chronic (low-level)
changes to the environment. Therefore, the presence of these different types of
organisms will reflect the nature and magnitude of any changes in the environment.
The biological environment of Filey Bay covers several different habitats which, as
with most marine areas, are inhabited by a very large diversity of plants and animals.
These habitats include the intertidal sandy beach of the Bay, the rocky shore of the
Brigg, the cliffs and rocky shore of the southern region towards Flamborough
Headland and the rock, sand and muddy areas found of the subtidal sea-bed (below the
tidal zone). In addition, the water column itself is an important biological habitat as it
supports plankton and fish which in turn support other parts of the food web. Each of
these habitats supports a particular biota which should be described before any
predictions of change due to anthropogenic activities can be made.
Using published and unpublished work, including studies carried out especially for this
report, the following sections assess the nature and structure of the biological
communities present in the area, their inter-relationships and the possible impact of
existing and proposed human activities within the Bay.
49
Chapter 3: The Biological Environment
3.2 Plankton
There is little information on the microscopic fauna and flora of the waters in this region
of the North Sea; this is an omission of concern because any activity likely to affect the
quality of the water column will change the composition and health of these plankton.
However, the transient nature of the populations and the dispersive nature of the
currents indicate that any effects are likely to be both short-lived and difficult to assess.
This is in contrast to the benthic communities (see section 3.3).
The North Sea has been divided into eight regions according to their plankton
communities (Fraser, 1965). One such region is the coastal waters of eastern England
and the plankton of Filey will have this community. However, more recent studies
indicate that the plankton communities of this part of the Yorkshire coast may be more
diverse than other areas due to the mixing of communities from the Channel and other
parts of the North Sea (MAFF, 1981).
The phytoplankton in the Filey Bay area consists largely of dinoflagellates (e.g
Noctiluca) and solitary and colonial diatoms (e.g. Rhizosolenia, Chaetoceros and
Skeletonema). These have well-defined seasonal cycles, especially the spring bloom which
further produces a succession of zooplankton population increases (see below). In addition
to the normal phytoplankton, at certain times of the year under a certain combination of
conditions, many of the coasts of the British Isles and continental Europe experience
dense blooms of phytoplankton organisms. Although these blooms occur only occasionally
along the southern part of the Yorkshire coast (J Nichols, MAFF Lowestoft pers. comm..),
the North-east English and South-west Scottish coasts regularly have blooms of 'red-tide'
organisms. In general, these are dinoflagellates which contain toxins and can occur in
densities sufficient to cause harm to higher animals (birds, fish and man) in the food web.
The higher animals may eat shellfish which have been feeding on the dinoflagellate blooms
causing paralytic and diarrhoetic shellfish poisoning (PSP and DSP). The red-tide
dinoflagellate Alexandrium (formerly Gymnodinium) has been responsible for blooms in
this area most recently in 1990 which led to the closure of mussel and some other
shellfisheries.
Often of greater concern, because of the aesthetic problems and fouling of nets, are
blooms of the colonial phytoplankton Phaeocystis. The eventual senescence of the
gelatinous colonies produces foam on beaches although in an open area such as Filey
Bay, the production and breakdown of these colonies is unlikely to produce any
adverse biological effect. In addition, scum produced by the eventual breakdown of the
short-lived phytoplankton blooms can give the appearance of sewage in the water
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Chapter 3: The Biological Environment
column. Phaeocystis blooms occur regularly along this coast (J Nichols, MAFF
Lowestoft pers. comm.) following calm, warm periods.
The microscopic animals (zooplankton) of the water column in this area consist of
holozooplankton, organisms which spend their lives in the upper water layers, and merozooplankton which are only planktonic for part of their life cycle. The dominant
holozooplanktonts are the calanoid copepods (e.g. Oithona, Paracalanus and
Centropages) and arrow worms (Sagitta) which provide food for the planktonic feeders
such as herring, sprat and sandeels. During the summer months there are large
concentrations of macrozooplanktonts such as jellyfish (e.g. Aurelia, Cyanea) and seagooseberries (Ctenophores such as Beroe, Pleurobrachia). The meroplanktonts include
the planktonic larvae of the shore and sea-bed organisms in addition to fish eggs and fish
larvae. As most of these organisms have well-defined breeding seasons,
meroplankton abundance is highly seasonal.
Despite the need for more detailed studies on the plankton of the area, the hydrographic
characteristics indicate that the area will have both a rich and diverse plankton. The
latter is a result of the particular features of the front crossing the North Sea from
Flamborough together with the nature of the coast and sea-bed. "However, as stated
above, anthropogenic activities which affect the water column, e.g increased sediment
resuspension or poorer water quality will have an impact on the plankton.
3.3 Filey Bay - the Biology and Sediments of the Sea-bed
3.3.1 Introduction
In addition to the use of benthic studies in assessing environmental impacts, the sea-bed
sediments and its organisms are of paramount importance in supporting inshore fish
populations. In turn, the fish populations will support the coastal sea-bird populations.
Many fish, especially the demersal species which live on or close to the sea-bed, feed
on the shellfish (crustaceans and bivalve molluscs) and worms (polychaetes) living in the
sediments. For example, many flatfish feed by cropping parts of these sedimentary
organisms which protrude onto the sediment surface. Because of this, it is important to
consider the amount of biological material (biomass) in addition to the abundance of
organisms.
Finally, the size of the local crab and lobster populations are dependent on the presence
of a suitable habitat. This is usually hard ground with suitable crevices which borders
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Chapter 3: The Biological Environment
onto sandy areas and is near to available food. The latter also consists of shellfish and
worms as well as small fish and the remains of other organisms.
3.3.2 Previous Studies
The biology of the rocky intertidal (shore) and subtidal (below the tide zone) areas
around Flamborough Head has been detailed by (Wood, 1988) and is summarised
below (section 3.3.4). The subtidal, soft-substrata, benthic communities of Filey Bay
were sampled by (Rees, 1975) and (Lockwood, 1972). In addition, studies of the
benthos of the Yorkshire coast, carried out at the Robin Hoods Bay laboratory by
(Newton, 1973),(Atkins, 1985) and (Moore, 1971) and by IECS (unpublished data)
add further information to the understanding of the area.
(Lockwood, 1972) assessed the characteristics of the Bay in relation to the feeding and
ecology of juvenile (0-group) plaice while Rees (loc. cit.) primarily assessed the
subtidal fauna of several sites along the North East coast. Similarly, (Moore, 1971)
described the general fauna inhabiting seaweed holdfasts and concentrated on a largescale pollution gradient which was evident along the south-eastern Scottish - northeastern English coast. The biological features of the area, and in particular the features
of conservation importance, have been summarised as part of the Marine Nature
Conservation Review carried out by the Nature Conservancy Council (Bennett, 1991).
The benthos of the Yorkshire coast appears to be only moderately diverse and low in
species richness despite having a relatively heterogeneous seabed structure (Atkins,
1985); (Newton, 1973); IECS unpublished data. The latter would be expected to
produce a richer fauna due to the availability of many habitat types. In assessing the
benthos in relation to the sediments, the previous studies detected an expected
relationship of increased benthic communities in areas with finer sediments, for
example in small patches of relatively rich muddy subtidal areas which occur along the
coast. However, in general the geographical position of the area together with its
sediment/wave energy characteristics appear to have combined to produce a less diverse
sedimentary fauna. In the context of the marine fauna of the British Isles, the English
north-east and Scottish south-east coasts appear to be relatively poor due to the lessened
influence of the warmer waters of the Gulf Stream.
Finally, the study by (Wood, 1988) of the hard substrata included an assessment of the
plants and animals whereas others, including the present study (see below) have
concentrated only on the animals. In addition to the importance of the latter as pollution
indicators and as food for fishes, the importance of the seaweed community decreases
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Chapter 3: The Biological Environment
with depth and thus it is not discussed further in relation to the sedimentary subtidal
area.
3.3.3 1991 Survey of the Soft-substratum Benthos
3.3.3.1 Introduction
A detailed survey has been carried out in order to provide an up to date assessment of
the sea-bed community and the types, abundance and biomass of organisms present. The
questions asked of the study, the nature of potential threats to the area and the time
constraints have dictated that the survey should be concentrated only on the sediments
and biota of the subtidal area within Filey Bay.
3.3.3.2 Methods
The sea-bed was sampled on 16th August 1991 at 21 sites within the Bay and a further
site on the central part of the Smethic Bank off Bridlington (Fig. 3.1). Two of the sites
visited were not sampled owing to hard (rocky) ground. These sites were stations 13
and 15 which were located on the underwater ridge which is an extension of Filey Brig
running north-west to south-east across the top of the survey area (Fig. 3.2).
At each of the remaining stations, a 0.1 m 2 . weighted van-Veen grab was used to
obtain a sample of the sea-bed sediment. The sample was subsampled for sediment
(particle-size) analysis and the remaining sediment was sieved through a 1mm mesh in
order to retain the larger organisms (macrofauna). Using a process of staining the
organisms and laboratory examination, an assessment was made of the type (species)
and abundance of organisms living in the sediment
3.3.3.3 Results
a) Biological Sedimentary Habitat
The results of the detailed sediment analysis are presented in Section 2.2.2 but a
subjective assessment of the sediment types has been used in order to interpret and
understand the benthic faunal characteristics (Fig. 3.3). The well-sorted sands along the
coast are replaced by muddy-sands at the southern central part of the area, and coarse
sands with shingle and gravel at the northern central area. The most seaward part of the
area has mud and muddy-sand sediment. These features are reinforced by estimating
the volume of residue remaining after sieving the grab samples (Fig. 3.4). Whereas
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Chapter 3: The Biological Environment
most samples had less than 100 ml of residue, station 9 in the central northern area had
more than 2.5 litres
The volume of grab sample taken at each station gives an indication of the compactness
of the sediment (Fig. 3.2). The degree of penetration by the van Veen grab increased
with distance offshore and was least in the northern part of the central and offshore
areas.
b) Benthic Fauna
The semi-quantitative analysis of the 20 samples yielded 69 taxa although this is not a
definitive list for the area. The species richness (i.e. number of types or taxa recorded at
each station) increases towards the southern inshore and central parts of the area (Fig.
3.5). A maximum of 18 taxa were taken in the samples indicating a moderately rich and
diverse area.
The abundance of each species has been recorded as single organisms, few, common
and abundant. In the case of the larger and more easily quantified organisms, an
abundance (as number per 1/10 sq.m.) for the sample is given. The distributions of
several of the taxa are given in Figs. 3.7 - 3.20. The inshore sandy area has a typical
community of organisms dominated by the polychaete worm Magelona mirabilis, the
bivalve mollusc Tellina fabula, and amphipod crustaceans (Figs.3.9 - 3.11). Each of
these organisms together with the remainder of the community, such as other bivalves
(Donax, Venus) are able to withstand the movement of mobile sands.
The polychaete worms Nephtys, Chaetozone and Scoloplos were widespread whereas
the bivalve Nucula and the polychaete Scalibregma were also widespread but only
where there is some mud in the sediments (Figs. 3.14 and 3.15). The razorshells
(Ensis/Cultellus) were present in the sands to the south of the area (Fig. 3.20) and the
sea-potato (Echinocardium cordatum) had a patchy distribution (Fig. 3.12). However,
these taxa burrow deep in the sediment such that they can be under-represented when
sampling compacted sediments. The soft-coral Dead-man's fingers (Alcyonium
digitatum) and the sea-spider (Pycnogonum littorale ) were only found at station 14 on
soft mud which bordered the rock ridge (Fig. 3.19). The bivalve mollusc Abra and the
brittlestars (Ophiuroids) provided the richest populations, in terms of biomass, in the
survey area; they were found predominantly offshore in the more muddy areas (Figs.
3.7 and 3.8). In particular, densities of Abra reached approximately 5000 per m2.
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Chapter 3: The Biological Environment
Finally, the sanded Ammodytes, which spends some time burrowed in medium and
coarse sandy sediment, was taken at several stations predominantly at the northern
inshore and central part of the area (Fig. 3.13). A maximum of 10 sandeels were taken in
a grab equating to 100 per m2 of sea-bed. The only other presence of fish was a juvenile
plaice taken at station 20 and fish eggs taken at stations 10 and 11 in the central southern
part of the area.
3.3.3.4 Discussion
The nature of bottom-living communities reflects the relationship between the type of
sediment, degree of water movement, depth of the sea-bed and supply of food for the
benthic organisms. These factors have combined in Filey Bay to produce the richer,
muddy deeper areas, the moderately rich inshore sands and the poor coarsesedimentary areas in the northern central part of the region.
The semi-quantitative assessment carried out to date has indicated that the bottom
communities are typical of the sediments and depths encountered and the geographical
area. There are no large populations of organisms which can tolerate and thrive under
polluted and disturbed conditions and the samples do not show any evidence of stress on
the sea-bed caused by pollution such as sewage discharges. The inshore sand
community is adapted to mobile sediments and will provide food for juvenile and
inshore fishes especially flatfish. In particular, in the inshore sand area, the siphon
tubes of the bivalves and the polychaete worms and amphipods form the diet of many
inshore fish especially the juveniles of flatfish such as dab and plaice. However, the
richest communities, in terms of the amount of biological material, is provided in the
deeper, muddy offshore areas colonised by large numbers of the bivalve Abra and
brittlestars.
The central northern region of the bay has coarse sediments of broken shell, gravel and
sands and consequently is both biologically poor and of little value as an inshore fish
feed ing area. However, the northern-most part of this area is of importance in
supporting an extensive colony of sandeels along its margin. This species in turn will
partly support the colonies of sea-birds along the Flamborough cliffs.
The survey carried out in 1991 reinforced many of the conclusions reached from
previous studies of the sea bed biology (Newton, 1973); (Atkins, 1985). Although
those previous studies surveyed the area to the north of Filey (Sandsend - Robin
Hood's Bay), when taken together with the present one and the qualitative study of
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Chapter 3: The Biological Environment
(Lockwood, 1972) it is concluded that in general the subtidal area of the Yorkshire
coast is only moderately rich. However, in certain small patches some organisms can
reach high abundances (e.g Abra in the present survey, Spiophanes in the previous
ones).
Th e area surveyed in 1991 had been sampled previously by (Rees, 1975) and
(Lockwood, 1972) although at present it is not possible to carry out a detailed
comparison of the three surveys. A cursory comparison indicates that while the
abundance of some species has changed, those changes are within normal variability and
the community essentially has remained the same. In contrast to the present survey,
(Lockwood, 1972) found sandeels present over much of the Filey Bay and a wide scale
dominance by the sand mason Lanice.
The bottom living animals which were preyed on by the fish differed with species. As in
most places, the siphon tubes of the bivalve Tellina and the tentacles of the worm Lanice
supported the juvenile plaice - these particular items regenerate in a selfregu lating system. The larger plaice and dabs take whole Lanice, Arenicola
(lugworms) and amphipod crustaceans. The offshore area determined in the 1991
survey to be inhabited by brittlestars (Ophiuroids) also appears to be use as a feeding
ground for small to medium sized dabs (Lockwood, 1972). Finally, the juvenile
gadoids (cod, whiting) inhabiting the area feed on the brown shrimp Crangon found
commonly throughout the Bay.
3.3.4 Rocky-shore and subtidal hard substratum
The hard substratum, predominantly rocky subtidal area around Flamborough Head
was surveyed by (Wood, 1988) using diving and underwater camera techniques. The
extensive underwater system of rock platforms is divided by gullies, especially to the
north off Speeton, and sandy areas extend from the inshore subtidal sandy substratum
of the north and central Filey Bay.
The rocky subtidal area off Flamborough Head was dominated by extensive seaweed
cover especially forests of kelp (Laminaria hyperborea) overlying a dense cover by red
algae. This algal dominated area extended to 6 m below the low tide mark and then was
replaced by an animal dominated zone. The latter was colonised by sessile organisms
such as sea mats (Bryozoans), seafirs (Hydroids), colonial and solitary tunicates,
sponges and the soft coral dead-man's-fingers (Alcyonium digitatum). Thus the
sedentary nature of these organisms enables them to withstand the strong tidal streams
present in the area. Other species such as the bivalve molluscs Hiatella arctica and
61
Chapter 3: The Biological EnvironmentZirfaea
Zirfea crispata and the spionid polychaete Polydora ciliata were also present as they
were able to bore into the soft rock. Finally, the most prominent mobile animals in the
area were decapod crustaceans (crabs and lobsters), starfishes and brittlestars although
there were only small densities of sea urchins (Echinus esculentus).
The relative paucity of the sedimentary communities along this coast (see above) is
contrasted with the apparent richness of the shallow rocky subtidal areas. This feature is
due in part to the position of Flamborough Head as a boundary between species with
northerly and southerly geographical distributions:
3.3.5 Fauna of the Sandy Beach
The fauna of the beach in Filey Bay was found to be dominated by organisms adapted to
the high energy conditions and mobile sands. Thus the dominant organisms were
amphipods crustaceans, mainly Haustorius and Bathyporeia, cumacean crustaceans,
Spionid and Nephtyd polychaete worms and the bivalve mollusc Tellina tenuis. In the
southern and central parts of the sandy beach, the upper shore areas were found to be
richer than the lower shore. Upto 750 amphipods and 25 Tellina and Nephtys were
found per square metre. The beach at Reighton in places had a community indicative of
organic enrichment as shown by the populations of Cirratulid and Spionid polychaetes
found there. In addition, it is not yet known whether parts of the beach are affected by
the freshwater run-off at Primrose Valley, Reighton Gap, etc.
The northern part of the beach had a more diverse community although densities of
organisms were lower than the other areas, upto 300 organisms per square metre. In
addition to the organisms occurring at the other parts, there were populations of
cumaceans and mysid crustaceans and the sand-mason polychaete Lanice.
The study has shown that the beach has a typical fauna of moderate diversity and
abundance. However, the organisms encountered are an integral part of the community in
the area. The amphipods and cumaceans taken in the sand at low water will migrate into
the water at high tide and thus be preyed upon by juvenile and inshore fish feeding in the
area. Similarly, the sediment dwelling polychaetes such as Nephtys and the bivalve
Tellina will also be taken wholly or in part by the fish especially juvenile plaice.
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Chapter 3: The Biological Environment
3.4 Filey Brigg
3.4.1 Introduction
Filey Brigg is a promontory of hard limestone, including some calcareous forms. It
projects into the North Sea in an east south-easterly direction. At the easterly end it
retains its covering of boulder clay and is then referred to as Carr Naze. The various
strata, of which the Brigg is comprised, dip in a southerly direction, producing large
gently sloping rock platforms. The scarp slopes of these platforms face in a northerly
direction and are almost vertical. Erosion by the sea, mainly on the northern side, has
produced large boulders, some of which remain in situ; the majority, however, have
been carried by the waves to the more sheltered southern side.
3.4.2 The Flora and Invertebrate Fauna
The plants and animals inhabiting Filey Brigg form a rich assemblage, the composition
and distribution of which is determined to a large extent by the orientation of the Brigg
itself. The north side is exposed to northerly and easterly winds and the waves they
generate whereas the south side is much less exposed, particularly at the western end in
the shelter of Carr Naze.
On the exposed northern side of the Brigg the higher rock platforms are colonised by
dense populations of common limpets (Patella vulgata) and the acorn barnacle
(Semibalanus balanoides). The former crawl over the rock surface feeding on
developing seaweeds as they progress, their finely toothed radulae (tongues) acting as
rasps. The barnacles, which are cemented head-down to the rock surface, push their
bristle-covered cirri (legs) out into the water where they catch tiny organisms which are
then transferred to the mouth. Many rock pools in this region have rich growths of the
seaweed Corillina officionalis. It is pink, purple or reddish in colour and the short
highly branched erect fronds are protected from the buffeting of the waves by a limey
skeleton. The rock surface of many of these pools takes on a pinkish-purple hue due to
the presence of a very hard encrusting film which is in fact another alga, Lithothamnion
sp.. The common periwinkle (Littorina littorea) is also common in these situations as is
the beadlet anemone (Actinia equina). The former feeds in a similar fashion to the limpet,
rasping plant material from the rock surface, whilst the latter use the sting cells on their
tentacles to capture and kill small organisms in the water; these frequently include the
juveniles of fish such as blennies. Fissures and small gullies in the rock surface also
support large populations of beadlet anemones, implying a rich source of food carried in
the tidal waters when they flow over the rocks. The almost vertical scarp slopes of
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Chapter 3: The Biological Environment
these high rock platforms frequently support large populations of rough periwinkles
(Littorina saxatalis (rudis)) and less commonly the small periwinkle (Malarapha
(littorina) neritoides). As with the common periwinkle both these species browse on
developing plants and lichens.
On the lower rock platforms the barnacles are almost entirely replaced by a carpet of
common mussels (Mytlus edulis). Occasional spaces in this covering are occupied by
common limpets and barnacles. The short, erect, dark brownish-red fronds of the
seaweed Mastocarpus stellatus often grow up between the individual mussels; it
is frequently the commonest alga present on these surfaces. Seasonally, the seaweed
Porphyra umbilicalis which is sometimes known as laverbread attaches itself to the
mussel's shells. Their shapeless fronds, which resemble sheets of dark purplish-red
polythene, may cover considerable areas. Another mollusc which occurs with the
mussels is the dog whelk (Nucella lapillus). This gastropod uses its modified radula to
bore a hole through the shell of a mussel prior to devouring the soft tissue inside. The
mussels themselves use their extensive gills to filter small planktonic organisms from
the tidal seawater. These dense patches of mussels often trap fine particles of sediment
and are able to hold moisture when the tide is out. This moist, sheltered micro-habitat
gives a foothold to many creatures which would otherwise be washed away by the
waves, or would desiccate during the low tide period. The green ragworm (Eulalia
viridis) is common in the interstices of these mussel mats as are a whole host of other
invertebrates, most notable of which are the amphipods (sand hoppers). Rock pools in
these regions frequently contain species of kelp (Laminaria digitata and L. saccharina),
and anemones. These latter also occur in fissures in the rock, beadlet anemones
tending to colonise the steep slopes whereas the dahlia anemone (Urticina felina) tends to
occupy the bottom. On the steep scarp slopes of these rocky platforms, near to low
water mark, the encrusting alga Lithothamnion sp. is very common, together with
several species of kelp and Alaria esculenta. The presence of this alga is indicative of
severe wave action. The plant is characterised by a long narrow frond which is very
thin with the exception of a very prominent mid-rib. When mature it attains some 90150
cm. (3-5 ft.) in length.
Running along the outer edge of the north side of the Brigg and extending for between a
half and one third of its length is a large rock platform. Between it and the rest of the
Brigg is a depression which is filled with seawater, the depth of which varies with the
state of the tide. This miniature arm of the sea contains many boulders, the majority of
which are exposed only at low water of spring tides. The outer rock platform, being very
substantial, affords the area behind it some protection from the most severe wave-
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Chapter 3: The Biological Environment
action. The boulders themselves increase the sheltering effect, particularly where the
spaces between them are narrow. The fauna is quite rich and comprises: several
species of sponge, hydroids, bryozoans, common starfish, bloody starfish (Henricia
sanguiolenta), brittle starfish, sea urchins, star ascidian (Botryllus schlosseri),
anemones, five species of crab, etc.. One of the sponges, the bread-crumb sponge
(Halichondria panicea) attracts the sea lemon Archidoris pseudoargus (a sea slug) which
feeds upon it.
At the eastern end of the Brigg the rocks are fairly low, flat and highly fissured. Most
notable is the large number of anemones, sponges and hydroids which line the fissures.
The southern side at the end of the Brigg comprises an extensive dip-slope which
usually supports very dense mussel populations. At irregular intervals tens of
thousands of common starfish (Asterias rubens) migrate from deeper water and feed on
the mussels. Due to the starfish's inability to withstand a great deal of desiccating they
rarely move above mid-tide level. After several weeks of this intense predation almost all
the mussels are removed up to a distinct 'predation line' which approximates to mid-tide
level. Once all the available mussels have been eaten the starfish return to deeper water.
The newly denuded rock surface is usually very rapidly colonised by the green seaweed
Enteromorpha intestinalis; the moist environment created by this plant is ideal for
recolonisation by more mussels.
The large dip slope which constitutes the majority of the south side of the Brigg is more
sheltered than the northern. In consequence, on the upper boulder-free section some
wracks occur, namely flat wrack (Fucus spiralis), bladder wrack (Fucus vesiculosus) and
serrated wrack (Fucus serratus). However, their distribution is quite dynamic, being a
product of limpet grazing, denudation, sedimentation and recolonising.
The lower section of the south side is almost totally covered in very large boulders.
Depending upon their orientation it is sometimes possible to observe some of the sessile
fauna on the under surfaces; sponges, hydroids, etc.. It is also possible to glimpse
edible, shore and spider crabs and other animals. However, it is not possible to study
the populations in any detail or with any degree of accuracy.
Projecting into Filey Bay from the south side of the Brigg is the remains of a pier which is
held by some to be of Roman origin. It is exposed at low water of spring tides and is easy
and safe of access. The rocks and boulders are of manageable size and it is
possible to study the flora and fauna on both their upper and lower surfaces. Some
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Chapter 3: The Biological Environment
indication as to the rich variety occurring here may be estimated from the following
species list which is concerned mainly with the fauna found between rocks and
boulders, on their surfaces and beneath them.
Invertebrate Species List:
Sponges:
Halichondria panicea
Grantia compressa
Bread-crumb Sponge
Purse Sponge
Hydroids:
Dynamena pumila
Tubularia larynx
Sea mats:
Various species
Anemones:
Actinia equina
Urticina felina
Beadlet
Dahlia
Nemertine worms:
Lineus longissimus
Bootlace worm
Polychaetes (Bristle worms):
Lepidonotus sp.
Harmothoe sp.
Cirratulus cirratulus
Marphysa sanguinea
Eulalia viridis
Spirorbis borealis
Pomatoceros triqueter
Nereis pelagica
Scale worm
Scale worm
Red-threads
Red rock worm
Green ragworm
Tube worm
Tube worm
Rag worm (in kelp holdfasts)
Molluscs (Shellfish):
Lepidochitoza sp.
Chiton/Coat-of-mail-shell
Patina pellucida
Blue-rayed limpet
White tortoiseshell limpet
Acmea virginea
Gibbula cizzeraria
Littorina littorea
Nucella lappilus
Grey topshell
Common periwinkle
Buccinum undatum
Dog whelk
Netted dog whelk
Common whelk
Trivia monacha
Cowrie (rare)
Nassarius reticulatus
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Chapter 3: The Biological Environment
Archidoris pseudoargus
Aeolida papillosa
Sea lemon
Grey sea slug
Anomia ephippium
Hiatella arctica
Saddle oyster
Wrinkled rock-borer
Mytilus edulis
Common mussel
Crustacea:
Gammarus sp.
Sand hoppers
Idotea granulosa
Carcinus maenas
(an isopod)
Shore crab
Cancer pagurus
Edible crab
Pagurus bernhardus
Homarus vulgaris
Galathea squamifera
Hermit crab
Lobster
Squat lobster
Galathea strigosa
Hippolyte varians
Squat lobster
Prawn
Porcellana longicornis
Porcellana platycheles
Long-clawed porcelain crab
Broad-clawed porcelain crab
Hyas araneus
Verruca stroemia
Semibalanus balanoides
Spider crab
Acorn barnacle
Acorn barnacle
Pycnogonum littorale
Sea spider
Starfish and sea urchins:
Asterias rubens
Common starfish
Henricia sanguiniolenta
Bloody starfish
Ophiothrix fragilis
Echinus esculentus
Psammechinus miliaris
Brittle star
Common sea urchin
Green sea urchin
Solaster papposus
Sun star
Sea squirts:
Botryllus schlosseri
Star ascidian
The gently sloping rock platforms which occur in the shelter of Carr Naze at the
western end of the Brigg are frequently covered with seaweeds. These exhibit vertical
zonation (i.e. each species occurs within a given vertical range on the shore which is
determined by the plants requirements for immersion in the sea or emmersion from it).
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Chapter 3: The Biological Environment
The sequence, commencing with the plant which occurs highest up the shore is given
below:
Highest:
Pelvetia canaliculata (Channel wrack)
Fucus spiralis (Flat wrack)
Ascophyllum nodosum (Knotted wrack)
and/or
Fucus vesiculosus (Bladder wrack)
Fucus serratus (Serrated wrack)
Laminaria saccharina (Kelp)
Lowest:
Laminaria digitata (Kelp)
Some of the animals also exhibit vertical zonation. There are large numbers of common
periwinkles on the middle and lower shore of certain parts of this area. These are
replaced by rough periwinkles higher up the shore, particularly on the rock cliff at the
base of Carr Naze. Earlier in this account reference was made to two species of
anemone, the beadlet and the dahlia. The former almost invariably occurs higher up the
shore than the latter.
Some of the raised rock platforms in this region are colonised by limpets and barnacles,
the activities of the former inhibiting the development of plant cover. In contrast, the
platforms close to the bottom of the shore are covered in seaweeds or seed mussels.
Fine particles of sediment derived from the erosion of the boulder clay on Carr Naze and
elsewhere collects in the spaces between the mussels, building up to a depth of 2 cm. or
more. This sediment is colonised by many species of polychaete worm
including Polydora sp. and Fabricia sabella. Both species construct tubes in which
they live from small particles of sediment and remove fine food particles from the
environment. Fabricia rarely exceeds 5 mm. in length, but frequently occurs in
densities in excess of one million per square metre.
Thus far, this account has centred upon the distribution of the plants and invertebrate
animals which inhabit the Brigg. The vertebrates, if one excludes man, are represented
mainly by the birds and fishes. The species of fish which are associated with the
Brigg, either through feeding or habitat preferences, are discussed in detail below
(section 3.4.1.3), and the birds are discussed in section 3.6.2.
68
Chapter 3: The Biological Environment
3.4.3 Small Fishes
The fishes have been studied intermittently over a period of many years. Specimens
have been captured from under rocks and stones by hand, with nets and with
anaesthetic Quinaldine from the pools. The anaesthetic allows the investigator to
resuscitate his catch and return it to neighbouring pools after identification and
examination. Since the anaesthetic is fish-specific and is benign to other organisms in
the environment it is a most valuable tool.
Shore fishes are in the main small, which aids them in: avoiding mechanical damage;
hiding in narrow crevices in the rock; and accommodating themselves in small
rockpools, spaces under rocks and stones and in amongst damp seaweed during the
low tide period.
Shanny or common blenny (Lipophyrys (Blennius) pholis) is light brown with blotches
and attains a length of 15 cm.. It is almost certainly the commonest inter-tidal fish on the
Brigg. It feeds on small molluscs and crustaceans. Some specimens will remove the
cirri (legs) of feeding barnacles, whereas large fish are capable of removing the whole
animal: the teeth form 'plates' at the front of the jaw and act as pincers. During the low
tide period they take refuge in rock pools, in crevices, under stones and amongst
damp seaweed. The skin is scaleless and mucous covered which enables the fish to
breath through its skin. (Daniels, 1971) found that the fish could, under
experimental conditions, survive in moist air for upto three days. Also it is capable of
supplying 60% of its respiratory needs via its skin. This fish is of southern origin and
breeds in the summer, laying the eggs in a 'cave' which the male subsequently guards.
The butterfish or gunnel (Pholis gunnellus) has a long body (circa 20 cm.) which is
laterally flattened, enabling the fish to enter very narrow spaces. The skin is smooth,
brown and covered with mucous which helps to prevent desiccation, and the fish can
be found under stones and weed or in rock pools during low tide. It is of northern
origin and breeds in winter when the female lays a golf ball sized mass of eggs which is
frequently guarded by both parents. On the west coast this phenomenon can be
observed on the beach whilst on the east coast it usually occurs sublittorally.
The sea scorpion (Taurulus bubalis) has smooth mucous covered skin and a large head,
eyes, mouth and fins making it an ideal lurking predator. The large pectoral and caudal
(tail) fins enable it to lunge very rapidly at passing prey which it engulfs with its large
mouth. Relatively large prey organisms are taken including small shore crabs, other
69
Chapter 3: The Biological Environment
crustaceans, worms and small fish. The eggs are laid in winter onto kelp holdfasts and
other suitable substrates.
The five-bearded rockling (Ciliata mustela) has a long and eel-like mucous covered
body and five barbels on the head. It occurs in pools and under stones, and it feeds on
crustaceans, worms and some molluscs. The northern rockling (Ciliata septentrionalis) is
often mistaken for the five-bearded rockling due to its similar habit, size (16cm in
length) and general appearance. It was considered to be relatively rare in the area, but it
has now been shown to be much commoner than previously thought.
The eel-pout or viviparous blenny (Zoarces viviparous) does not usually exceed a
length of 18 cm. on the Brigg but can reach 40 cm.. The body is again long, eel-like
and mucous covered and the fish feeds predominantly on crustaceans, with some
worms and molluscs. Gravid (pregnant) females are found on the shore in winter
where they give birth to live, fully-formed young which are about 4 cm. in length.
The lumpsucker or sea hen (Cyclopterus lumpus) has a large, thick scale-less body
with four rows of boney plates along the sides and a large sucker on the underside.
Females can grow upto 60 cm. in length whereas the smaller males may only reach 50
cm.. This fish comes inshore to breed in February and occasionally males can be
found guarding their football-sized mass of eggs in pools or large crevices near low
water mark. Larvae, upto 2 cm. in length, can be found in rock pools in September
and October.
The sea or fifteen-spined stickleback (Spinachia spinachia) (10 cm. length) is not very
common on the Brigg but when it does occur it is always in the pools. This relative of
the three-spined stickleback has a very small mouth into which it sucks the small
crustaceans and other organisms which are its food.
Worm pipefish (Nerophis lumbiciformis), as the name suggests, are long (15 cm.) and
thin and they can occasionally be found under stones near low water mark. They are
related to the sticklebacks and feed in a similar way. In summer the males carry the
eggs about attached to the undersides.
The two-spot goby (Gobiusculus flavescens) (3 cm. in length) is not abundant on the
Brigg but occurs regularly. It always inhabits rock pools where it feeds in mid-water
on small crustaceans and other prey.
70
Chapter 3: The Biological Environment
Montagu's sea snail (Liparis montagui) is a small fish, approximately 6 cm. in length,
which at first sight resembles a tadpole. It has a well-developed sucker on the under
surface which it uses to attach itself to kelp fronds, the sides of pools and the under
side of rocks. It occurs frequently but in small numbers and feeds on a wide range of
small animals.
Juvenile specimens of ballen wrasse (Labrus bergylta) are occasionally taken in rock
pools low down on the shore, and small specimens of the flatfish toptknot (Zygopterus
puzctatus) are very occasionally found under boulders.
The fishes mentioned above can be found when the tide is out, but it should be
remembered that at high tide much larger fish from deeper water move onto the shore to
feed: cod, flounder and wrasse are but three examples. They consume a wide range of
Brigg fauna.
3 .5 L arg e r F is h es
3.5.1 Plaice
3.5.1.1 Introduction
The warm brown colour and brilliant red or orange spots, make the plaice arguably the
most familiar flat fish in northern waters. Much research has been directed, over a
period of many years, towards an understanding of the biology of this popular food fish,
which is common in Filey Bay where it is exploited commercially. It is the most
important flat fish in the European fishery with, for example, the total catch in 1963
being approximately 150,000 tons, a quarter of this going to the UK.
(Wheeler, 1969) summarises much of the research into the development, growth rates,
diet and dietary preferences of this species. The following is a precis of his account. It is
found in shallow water, from the shore-line down to about 73m in the UK, deeper
elsewhere. Spawning occurs in the North Sea from December to March, in Danish
waters from February to March and March to April in the south-west of Iceland.
Mature fish congregate in certain spawning grounds, to which they migrate over quite
considerable distances. One of the most important grounds lies in the southern North Sea
in about 37m of water. Once spawned, the eggs, 1.8 - 1.9mm in diameter, float to near
the surface, but sink gradually as development proceeds. Hatching, which is temperature
dependant, usually takes place in 18 - 21 days. The 6.5mm larvae
71
Chapter 3: The Biological Environment
eventually commence feeding on minute plant and animal plankton. These larvae are
similar to those of round fish like the cod etc. After about forty days, metamorphosis
occurs and the little flat fish settle on the bottom, length usually between 10 - 13mm but
may be as much as 17mm. Once on the bottom, they drift inshore into very shallow
water where they continue to grow and feed. They may attain 6 - 8cm in their first
winter, and 10 - 13cm in their second, when they are living in slightly deeper water.
Those which stay in inshore waters for their third winter, usually only a small
proportion of the population, average 15 - 20cm. Almost all plaice in their fourth
winter are in deeper water and their average length is between 25 and 27cm. Thereafter
they continue to grow until at nine years of age they have attained an average length of
41cm. Although the intensity of modern fishing usually does not permit, the plaice is
capable of achieving a length of 61cm at the age of 20 years, i.e. females; males rarely
live beyond ten to twelve years.
Just after metamorphosis, the young plaice feed upon polychaete worms and
harpacticoid copepods (crustaceans) As they grow the diet becomes more varied and
includes many more crustaceans. Further growth leads to the fish consuming more
molluscs, until they move into deeper water, where, from the third year onwards, they
eat mainly molluscs including: small scallops, dog whelks, cockles, the razor shell
Ensis, Mactra, Abra and many others. Crustaceans are also important in the diet and
include small individuals of most crab species: swimming crabs, shore, edible, hermit,
and masked crabs; brown shrimps; mysids; and Idotea. Worms are the other main
foo d group and include ragworm , lugworm , and the sea-mouse Aphrodite.
Echinoderms (mainly brittle stars) and fishes (mainly sandeels) provide the balance.
3.5.1.2 The Plaice of Filey Bay
The shelter afforded by the Brigg, and the sandy bottom in a larger area of the bay,
makes it a suitable nursery ground for this fish. Detailed studies of south-west coast
nursery grounds were carried out in the late 1960's and in order to facilitate
comparison, the work at Filey was intensified.
3.5.1.3 Spawning, distribution and movements of 0-group plaice
The major plaice spawning grounds in the North Sea occupy areas to the south and
east. There are some more minor ones to the west i.e. along the north-east coast of
England and Scotland (Fig 3.21), from Flamborough Head to the Moray Firth.
Although spawning may occur from November to April (Simpson, 1959), the greater part
of egg production between the Flamborough Off Ground and Berwick Bank
72
Chapter 3: The Biological Environment
occurs between February and April (Simpson, 1959) and (Harding, Nichols, &
Tungate, 1978).
From samples of plaice eggs and larvae, combined with current speeds and direction, the
same authors concluded that in 1976, the 0-group plaice, (i.e. up to one year old) which
recruited to the nursery grounds along the Yorkshire Coast, were spawned between
Flamborough Head and the Fame Deeps. Thus a link was established between
these two spawning grounds and Filey Bay. (Lockwood, 1974) recorded the arrival of
plaice larvae in Filey Bay during late May and June. The depth of water in which they
settle is unknown, except that it exceeds 5m. The distribution of the last stages of larval
development - stages IV - V is shown in figure 3.22.
On completion of metamorphosis the 0-group fish, length 16 - 20cm moved into
shallow water (2 - 5m) and concentrated in the region of Filey Town. The first larvae to
complete metamorphosis colonised the water just to the seaward side of the surf
zone. By maintaining this position these fish are able to exploit the intertidal region for
food and are less venerable to predators such as gadoids (cod etc) and larger flat fish.
The distribution depicted in fig 3.23 remained fairly constant throughout July and most of
August. In September and October (figs 3.24 and 3.25) the centre of population was still
identifiable, but was much less that previously.
Towards the end of August, the larger fish move into deeper water, their place near the
surf zone being taken by smaller members of the population. Lockwood suggests that
the length at which the fish start to move into deeper water is 40- 50mm. Winter
sampling was mot possible, so further information regarding movements of the 0group population were obtained from tagging experiments. This showed that the mean
length at which juvenile plaice first leave Filey Bay is 74mm and are longer than
118mm when they move well away from the bay towards Flamborough Head - many IIgroup fish were captured here. From this region, the fish begin to move north
against the residual current in the direction of the parental spawning grounds. It should be
noted that some larger plaice do remain in Filey Bay and these form the basis of the
fishery.
3.5.1.4 Food
Initially, 98% of the food of 0-group plaice in Filey Bay, comprises the tentacles of the
sand mason worm Lanice conchielaga (Lockwood, 1972) and (Lockwood, 1984).
This worm builds a tube of sand grains and shell fragments etc., from which numerous
tentacles are extended. These are moved over the sand surface where they collect small
74
Chapter 3: The Biological Environment
organic particles which constitute their food. The 0-group plaice 'graze' on the tips of
these tentacles. It is interesting to note that (Macer, 1967), working on 0-group plaice in
Red Wharf Bay (Anglesey) found them feeding upon spionid (polychaete worm)
tentacles. The principle prey species in Loch Ewe were the siphons of the mollusc
Tellina (Edwards, & Steele, 1968). As these tiny plaice develop in Filey Bay, their
food preferences change, with harpact harpacticoid crustacea becoming important prey.
Figure 3.26 shows the relative importance of various prey organisms on a monthly
basis and with increasing size of the fish.
The animal populations inhabiting Filey Bay form an interdependent community bound
together by predator/prey relationships. Table 3.1 gives some indication as to which
fish species prey upon one another. These data should only be taken as a rough guide,
given the size of some of the samples and the fact that they were obtained during a six
month period. Personal observations (ongoing investigations, D.B. Lewis) of weever fish
(Echiichthys vipera) diets in both Filey and Bridlington Bays, indicate that this sp ecies
sometim es eats large numbers of sandeels and gobies. At certain times this summer
(1991) cod were found to be feeding almost exclusively on the very numerous shoals of
herring (pers. comm. R. Watkinson).
Table 3.2 illustrates the relative importance of invertabrate organisms in the diet of the
fishes of Filey Bay. Again, these data should be taken as an indication as to food
preference, especially where the sample size is small. The data indicates that cod are
the only major predator on shrimps Crangon crangon, however, weever fish gut
analyses show that they too sometimes consume significant numbers of these
crustaceans. Cod caught on rod and line at Filey, immediately after a very severe storm
were found to contain up the 50 large lugworms per individual. The worms had been
dislodged from the sand by the waves (pers. obs. D.B. Lewis). The diet of 0-group
plaice in Loch Ewe, Filey and Red Wharf Bays indicates how variable the choice of
prey organism can be.
3.5.2 Sandeels
There are two main species present. The sandeel Ammodytes tobianus, maximum
length 20cm (8") which occurs closer inshore than Raitt's or the lesser sandeels
Ammod yt es marinus, maxi mum length 24cm (9.5"). The latter occurs more
commonly.
Sandeels are important dietary items of many of the fishes of Filey Bay, in fact small
specimens are frequently taken by mature individuals of the species. They are also of
77
TABLE 3.1
Piscivorous fishes.
Analysis of the importance of fish as prey by percentage occurrence, and a record of the maximum number of prey found in the stomach of one predator.
Predator Species
Sample
Size
No of Fish % Feeding
Prey Species
With Food
on Fish
in Stomach
Dab
Plaice
A B
Plaice
0 group
l+group
Dab
50-100mm
100+mm
Sole
Turbot
Flounder
Cod Family
Monk/Angler Fish
Sandeel
Lesser Weever Fish
Dragonet
Gobies
Pogge/Hooknose
Pleuronectes platessa
Limanda limanda
Solea sloea
Scophthalmus maximus
Platiciithys flesus
Gadoididae
Lophius piscatorius
Ammodytes spp
Echiichthys vipera
Callionymus spp
Gobius ssp
Agonus cataphractus
334
859
289
580
156
419
20
9
3
122
6
113
193
111
90
35
154
336
10
9
3
96
5
55
129
103
53
24
Column A - Percentage of feeding fish found with fish in stomach
Column B - Maximum number of fish in one stomach
Sandeel
A
AB
B
Gables
Cod
A B
AB
Herring
Sole
A B
Indeterminate
A
Lesser
Weever
A B
A B
12.9
1
2
-
-
9.8
5
0.2
1
-
- -
-
0.5
3
-
-
1.4
5
40
66.7
10
17.7
10
1.2
40
44.4
33.3
20
1
6
10
1
3
-
1
1
3
1
2
8
3.1
60
1
4
1
-
1
-
-
-
-
-
22.2
-
-
1
20
1.8
11.1
66.7
60
3
-
2.1
11.1
125
-
14
6.8
1.6
2
2
3
1.6
-
1
-
-
-
-
-
-
---
-
-
-
-
-
9.3
4.9
16.7
4.2
1
-
-
-
-
-
-
-
- -
-
-
-
-
-
12.5
TABLE 3.2
Analysis of stomach contents of all fish species caught in Filey Bay.
The food groups are those usedin describingthe dietof0-group plaice, withthe further separationof PiscesandCrangonfromthe general group'Others'. Other groups are separatedwhere they are Important The dashes
denote theoccurenceof a particular foodinsmall samplesof fish.
Species
Plaice
0-group
Pleuronectes platessa
> 0-group
Dab
0-group
50-105 mm
>100mm
Solea solea
Turbot
Flounder
Cod
Whiting
Saithe
Haddock
Monk/Angler Fish
Sandeel
Herring Family
Leaser Weever Fish
Dragonet
Gobies
Pogge/Hooknose
Pipe Fish
Butterfish
Gurnard
Soignette
Bullhead/Sculpin
5-Bearded Rockling
Sample
Size
No of Fish
With Food
in Stomach Errant
Polychaete RN
(worms)
Sedentary
Amphipods
(Crustacea)
RN
Cumaceans
(Crustacea)
RN
Molluscs
Others ' I
RN
RN
Brown Shrimp
C. crangon
RN
Fishes
(Pisces)
RN
334
45
14.9
64
25.6
16.3
18
19
0.3
0.7
859
279
10.2
75.2
1
0.3
1.9
11.2
19.9
0.9
228
156
419
20
9
3
15
64
35
21
2
83
10
0.5
83.1
14.5
80.5
3.6
6.8
17.5
1
1.3
11.1
11.1
14.5
52.6
39.8
50
33.3
50
11.1
27.3
20.8
12.5
123
4.2
123
222
45.4
45.8
25
6
113
19
193
111
90
35
19
10
6
4
3
2
1
58
5
64
8
37
11
10.9
9.1
1.8
1.8
20.4
1.9
1
Miscellaneous
Limanda Limanda
Sopthalmus maximus
Platicthys flesus
Gadus morhua
Merlangus merlangus
Pollachius virens
Melogrammus aeglefinus
Lophius piscatorius
Ammodytes spp.
Clupidae
Echiichthys vipera
Callionymus lyra
Gobius spp.
Agonus cataphractus
Synathus spp
Pholis gunnelus
Trigla spp
Buglossidium luteum
Myeacepholuslreurulus spf
Ciliata mustela
8
72.1
5
34.5
10
6
9
11
1.8
12.5
1.9
1
*1 'Others' Includes: Indeterminate remains, unidentified nematodes, trematodes and occasional crustaceans.
'2 Only whiting < 50mm had copepods in the stomach.
13.2
68
32.1
33.3
47.4
90
-
5.3
-
50.9 .
14.3
69.8
94.2
96.2
79.2
47.4
20
-
3
5
40
66.7
100
11.1
18.2
373
10
3.6
37.2
1
3.8
16.7
-
Star Fish Echinoderms 22.1%
22.1%
77..8
40 *2
45.8
373
Copepods 15.5%
Copepods 67.3%
Copepods 85.7%
Chapter 3: The Biological Environment
major importance to the birds, and in particular to the populations of breeding puffins,
guillemots and rezorbills etc. on Bempton Cliffs.
These fish are also important in man's economy. They form the basis of an industrial
fishery, being rendered into fish meat and oil for feeding livestock, etc. The first large
scale sandeel fishery in the North Sea commenced in 1953, when the Danes landed 4500
tons at Esbjerg (Popp Madsen, 1957). The fishery has grown rapidly since then, with UK
fishermen participating from 1960 exploiting the Dowsing Bank, some 60-70 miles off
the Humber ports (Macer, & Burd, 1970). This stimulated research into the biology of
Raitt's sandeels by (Macer, 1966) of the MAFF (Ministry of Agriculture, Fisheries and
Food) laboratory at Lowestoft. The food was found to consist of planktonic
animals including: copepods, amphipods, decapod crustacean larvae, annelid
worms and fish eggs and larvae. The range of food items is very large. It was observed
that fish of this species were caught almost exclusively during daylight hours and
seasonally i.e. mainly in Spring and Summer, with no fish available in the Winter.
In order to explain the above observations, (Winslade, 1974a, b and c) conducted a
series of laboratory experiments into the behaviour of these fish. The results showed that
Raitt's sandeel may swim freely in the water column or dive into the sand where they
adopt one of two postures
a)
they may lie partially emerged, with their heads protruding into the
water, or
b)
may lie totally buried.
When in the latter posture, the fish are only just under the sand surface. The fish
commence swimming just before it gets light. This is under the control of a circadian
rhythm (biological clock). They will continue swimming only if the light level is high
enough and food is present in the water. High levels of swimming activity were
recorded in light regimes of between 1000 and 100 lux, below this, activity declined
rapidly.
The threshold light intensity for swimming activity in the aquarium was estimated at
approximately 20 lux, although Winslade is of the opinion that on the fishing grounds it
m ight b e higher than this, possibly in the region of 100 lux. This level of
illumination is not normally reached in Winter on the Dowsing Bank and 20 lux is only
exceeded for a few hours each day. The very low levels of swimming activity in
Winter could therefore be related to low light intensities.
81
Chapter 3: The Biological Environment
As referred to above, swimming activity is only maintained if food is present and
sandeels, like that other important group of plankton feeders the clupeids (herring,
sprat and sardine etc.) are visual feeders. Winslade also demonstrated that the olfactory
sense (sense of smell) was not involved in sanded feeding behaviour. In addition low
temperatures were shown to inhibit swimming activity. An examination of the head of
A. marinus reveals that the dorsal side of the skull is very transparent and the pineal gland
("third eye") is clearly visible lying on top of the brain, which suggests that it might be
involved in light perception. Values of sensitivity of this gland in other species
range from 2x 10-2 - 10-6 lux (Morita, 1966); (Hanyu, & Niwa, 1970). Although
no values are available for A. marinnus, if however the sensitivity is comparable
with other species, particularly at the lower end of sensitivity range, then the pineal
gland should enable the fish to be aware of changes in illumination, even when buried in
the sand.
We are thus concerned with a fish which spends most of the winter buried in the sand
because of low levels of light, temperature and available food. In Spring, light
intensity and temperature increase and in consequence the phytoplankton (plant
plankton) reproduces rapidly, so that by April, the copepod crustaceans which feed on
phytoplankton have attained huge population densities. At this tim e light and
temperature levels are sufficiently high to stimulate swimming and feeding activity in
the sandeel population. This activity continues to increase, peaking in June.
Thereafter, there is a slow decline into Autumn and cestation in winter.
The breeding activity of the seabirds on Bempton cliffs is clearly synchronised with the
swimming activity and consequent availability of the sandeel population in April and its
peak in June.
Sandeels and to a lesser extent herrings are very important members of the food webs
and chains in Filey Bay, particularly with respect to other fish species and birds. In the
sea, as on the land, it is the plants alone which have the ability to absorb energy from the
sun and use it to synthesise organic compounds. The vast majority of plants in the sea
are very small and comprise the phytoplankton (plant plankton). The zooplankton
(animal plankton) obtains its energy by eating the phytoplankton. Plant produced
energy is obtained by the sandeels when they, in their turn, consume the zooplankton. To
the sea birds and many fish species, sandeels and herring represent a rich source of
available plant derived energy. The phytoplankton --> zooplankton --> sandeel -->
puffin food chain is somewhat similar to the way in which a sparrow-hawk obtains
82
Chapter 3: The Biological Environment
plant derived energy when it consumes a blue tit which has been feeding upon
herbivorous insects.
Dredging or similar activity leading to disturbance of the sea bed could affect the
sandeel population in several ways. Total removal of the sand would prevent the fish
from burrowing into the sea bed during the hours of darkness, to overwinter in safety, or
to avoid immediate danger from predators. If the operations resulted in large
amounts of very fine particulate matter in suspension in the water, then the resulting
lowering of light intensity and visibility could interfere with their feeding behaviour, they
are visual feeders. If low enough, the fish may simply remain buried in the sand; given
that the area of high turbidity extends over undredged areas. Lowering of illumination
could affect the production of the phytoplankton and in consequence the zooplankton
which constitute the food of the sandeels. If this were to occur, there would be a
knock-on effect involving breeding sea birds and many fish species.
3.5.3 Exploitation of the fish stocks
This is best considered by sub-dividing the region into the areas depicted on figure
3.27.
Area A. Much of this lies within the prohibited area, the limits of which are defined as
lying 'Between a line drawn true East by South-half-South from the extreme South end of
the Filey sea wall and a line drawn true North-East from the Coastguard station at
Speeton.' (taken from North Eastern Sea Fisheries Committee Year Book 1989- 1993)
(figure 3.28). The prohibition refers to trawling. The substrate is of rock.
Fishing method employed
i)
Long lining from Filey cobles, in winter for Cod, although som e other
ii)
economically valuable fish such as Whiting are also taken.
Gill netting. In summer and winter for Cod, Sole and some Angler (Monk) fish.
iii)
Trawling on the rock to the north of the prohibited area, for Cod. This is mainly
iv)
prosecuted by Scarborough boats.
Potting. Lobster pots are set in this area, mainly by Filey cobles, the catch,
lobsters and edible crabs.
83
Chapter 3: The Biological Environment
Area B. The substrate is of gravel; the coarser elements being to the North.
Fishing method employed
i)
Long lining in winter from Filey cobles, mainly for Cod.
ii)
iii)
Trawling in summer for Sole and other flat fish.
Trawling in summer at the interface with area A by both Scarborough and Filey
boats.
iv)
Potting for crabs and lobsters by Filey cobles, but less frequently than in area A.
Area C. The substrate is mainly of sand.
Fishing method employed
i)
ii)
Gill nets.
Small Otter trawls (approx. 10 metres)
Both the above are shot from Filey cobles for Sole, but they also land Dabs,
Plaice, Turbot and Brill. There is little fishing activity in this area in the winter.
Area D.Substrate mainly sand, it is similar to area C.
Fishing method employed
i)
Trawling by Scarborough boats in summer, for Sole, Plaice and other flat fish.
ii)
Trammel netting in summer, mainly for Sole.
Area E. Flamborough Ground. Substrate mainly rock.
Fishing method employed
i)
Long lining mainly in winter for Cod and Whiting.
ii)
Trammel netting all the year round, but concentrated in the winter, for Cod, Sole,
Plaice, Dabs, Lemon Sole and Rays.
iii)
iv)
Gill netting for Cod, Sole, Plaice, Dabs, Lemon Sole and Rays.
Potting for Lobsters and Crabs, all the year round, but more effort in the Spring
and Summer.
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Chapter 3: The Biological Environment
The bulk of the fishing effort in this area is carried out by Bridlington boats with
occasional Scarborough trawlers and Filey long liners.
Area L Land Rock (Colloquialism for the rocky substrate adjacent to the coast). This
area is fished by all traditional methods. In addition, from the South side of Brigg, `J'
nets are fished, the main catch being Sea Trout and the occasional Salmon. In August
1991, nine nets were in operation, with two licences not taken up. This decline in
fishing effort trend seems likely to continue since there is less demand for 'wild' Trout
than the fanned product. This is apparently due in part to the colour of the flesh which
can be achieved by manipulating the diet of captive fish.
The fishing areas outlined above, are essential to the survival of the Filey coble fleet
and to the boats from Bridlington. They are also of lesser importance to the
Scarborough Fleet.
3.6 Bird Ecology
3 .6 .1 Bi rds As s oci ate d wi th t he Chalk Cli ffs of th e F l amb or ough
Headland
3.6.1.1 Introduction
The chalk of the Yorkshire Wolds ends abruptly at the East coast in a stretch of
precipitous cliffs between Sewerby and Speeton, thus forming the coastline of the
Flamborough headland. The cliffs, which rise to a maximum height of about 135 m.,
support the largest seabird colony in England with more than 100,000 breeding pairs.
This massive population is the result of a combination of factors which all contribute to
the location's suitability for seabirds. Firstly, the geology and structure of the chalk
has encouraged the cliffs to weather into numerous ledges and fissures, thereby
creating ideal nest-sites for several species of seabirds. The cliffs are amongst the
highest in Britain and thus act as a focal point for any seabirds searching for breeding
areas or migrating along the East coast. Also, the sheer size of the towering vertical
cliffs means that the nest-sites are very abundant and that they are inaccessible to most
predators. Another contributory factor is the development close inshore during the
summer months of the 'Flamborough front' - the surface boundary separating the
permanently mixed waters of the southern North Sea from the seasonally stratified
water of the northern North Sea - which extends roughly from Flamborough Head to
the German Bight (see section 2.1.2). Frontal systems such as this have been noted as
87
Chapter 3: The Biological Environment
areas of high plankton abundance due to either favourable light and nutrient conditions at
the front or a method of passive convergent accumulation towards the front. The
relative importance of these two different mechanisms is still unclear, but work on the
eastern end of the Flamborough front in the German Bight suggests that, in this case,
passive convergent accumulation is the dominant method. The elevated plankton
abundance may have a significant affect on the entire food web, instigating increased
productivity in higher trophic levels. In this way, the presence of the Flamborough
front in summer may indirectly enable the area to support elevated populations of
seabirds via increases in the productivity or abundance of fish and invertebrate
populations.
The cliffs of Flamborough Head are the breeding sites for close to 250,000 seabirds.
The north-facing cliffs support major colonies, some of international importance, with
about 75,000 pairs of kittiwakes (one of Europe's largest colonies), 30,000 pairs of
guillemots, 3,200 pairs of razorbills, 3,000 pairs of puffins (England's largest colony),
950 pairs of herring gulls and 830 pairs of fulmars, the largest numbers being found at
Bempton and Breil Nook. Bempton Cliffs were particularly noted as the only mainland
gannetry in the UK, with a population of 1250 breeding pairs in 1991, but this is no
longer the case since the establishment in 1988 of a small 'colony' consisting of only a
few breeding pairs at Troup Head, Aberdeen. Several lengths of the Bempton and
Buckton Cliffs, amounting to 2.5 miles, were purchased by the RSPB between 1969
and 1972. Further acquisitions have been made more recently. Although the birds
spend much of their time in the open North Sea and North Atlantic where they are
vulnerable to hazards such as oil pollution, this reserve affords them a permanent
sanctuary for their vital nesting season on land.
Most seabirds spend their winter months out at sea before they start returning to the
cliffs in early spring to locate favourable nest-sites. By June every available space is
occupied, and since each species prefers a slightly different situation on the cliff from
the others a zonation of species can often be identified. The birds are resident on the
cliffs from February to September/October although most species are there for a more
limited period. The parent birds spend a great deal of time at sea gathering food for
young, usually within a few kilometres of the shore but sometimes extending their
search to a radius of 25-30 kilometres offshore.
3.6.1.2 Ecology
Puffins (Fratecula arctica), guillemots (Uria aalge) and razorbills (Alca torda) are all
members of the Auk family (Alcidae). Being small, compact birds with stubby wings
88
Chapter 3: The Biological Environment
they are ideally suited to swimming underwater in search of fish, the prey consisting
mainly of sand eels, sprats and whitebait. The guillemot is the most numerous auk on
Bempton Cliffs, packing tightly together along narrow cliff ledges where they lay their
single, oval egg on the bare rock. Razorbills prefer the more secluded crevices or
holes, whilst the puffins rear their single chick within small caves, burrows or deep
fissures usually near the top of the cliff. Guillemots and razorbills return to the cliffs
early in the new year after assembling offshore, but they do not lay their eggs until late
April or early May. Puffins, however, come to land to breed from late March onwards,
and the young birds fledge in July or even early August. The Auks feed by diving
from the water surface, using their wings as paddles underwater to chase their prey
before catching in the beak. Sand-eels and other small fish (the major food source) are
carried back to the nests in the beak to feed the young during June and July. Most
Auks have deserted the cliffs by the end of July.
Gannets (Sula bassana) started nesting on Bempton cliffs during the 1920's. Although
there were only 21 pairs at Bempton in 1969, the colony grew markedly during the
1970's and '80's with 600 nests counted in 1985, about 810 breeding pairs in 1988
and 1250 in 1991. These large, majestic birds can span upto 6 feet with their narrow
wings outspread, the mature birds being pure white with black wingtips and yellowtinged napes. The immature gannets are brown, then mottled to a decreasing extent
until they reach maturity at 4 to 6 years when they gain their adult plumage. Some of
the Bempton gannets have originated from other colonies but others return after 2 or 3
years to their birth-place. These birds mix with the immature gannets to form 'clubs'
on the main, breeding colony's extremities so that there may be upto 400 non-breeding
birds associated with the colony each season. Gannets are renowned for their
spectacular fishing technique. An individual or group of birds will plunge head-first
into the sea from as high as 100 feet above the surface, grasping a herring, mackerel,
sand eel or sprat in their dagger-like bills and often swallowing it underwater. The
Bempton gannets return from the sea in January/February and lay their single eggs
early in April. The chicks hatch in May and are ready to leave the cliffs in late August
or September, and they can swim some distance out to sea before they are able to fly.
In their first winter they may fly as far south as the coast of West Africa. Gannets
gather seaweed and other flotsam from the sea with which to build their nests.
Unfortunately, this includes pieces of potentially lethal nylon line and netting discarded
from fishing trawlers. This can entangle both adults and young, condemning them to a
lingering death. In 1984 coastguards descended the cliffs and removed many sackfuls
of nylon from the nesting ledges.
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Chapter 3: The Biological Environment
By far the most numerous occupants of Bempton Cliffs are the kittiwakes (Rissa
tridactyla) which at the last census were estimated to be of the order of 75,000 pairs three times greater than the population of the 1960's. This gull spends most of its life
above the open sea feeding on sand eels and other small fish, only coming to land to
breed where it constructs a neat nest on a tiny ledge or buttress. Although some great
black-backed gulls (Larus marinus) wait below the cliffs to snatch any young seabirds
that accidently fall from the ledges, herring gulls (Larus argentatus) are the only other
species of gull to breed at Bempton, where they occasionally predate the eggs and
chicks of kittiwakes and Auks. These gulls should not be confused with the fulmar
(Fulmarus glacialis) which, although gull-like in appearance, is actually a member of
the petrel, or tube-nose, fam ily (Procellariidae). This species has undergone a
remarkable population explosion around the coast of the British Isles, possibly due to
its ability to exploit the fish offal from trawler fleets, and now numbers about 800 pairs
at Bempton. More naturally, fulmars feed on crustaceans, cephalopods and fish.
Fulmars nest in the broader ledges and in the alcoves of the cliffs from where the young
do not fledge until August or September.
Seabirds are not the only cliff nesting species; resident birds such as blackbirds (Turdus
merula), starlings (Sturnus vulgaris), house martins (Delichon urbica), rock doves
(Colu mba livia) and jackdaws (Corvus monedula) also inhabit the ledges and
platforms.
At the foot of the cliffs upto 40 shags (Phalacrocorax aristotelis) - large glossy dark
green birds, similar to the cormorant (Phalacrocorax carbo) - nest in the boulders and
caves feeding mainly on flat fish, and can be seen flying low and direct over the water.
The larger cormorant does not breed at Bempton but can sometimes be seen flying in a
similar way at the base of the cliffs.
The rocky foreshores, coves and bays around the headland are also populated by many
other species of bird, especially during the winter. Oystercatchers (Haematopus
ostralegus), dunlins (Calidris alpina), sanderlings (Calidris alba), turnstones (Arenaria
interpres), purple sandpipers (Calidris maritima), redshanks (Tringa totanus) and
ringed plovers (Charadrius hiaticula) are all relatively common visitors to the area.
Other birds found on the foreshore, particularly at the high tide mark, include rock
pipits (Anthus spinoletta), lapland and snow buntings (Calcarius lapponicus and
Plectrophenax nivalis) whilst closer to the water's edge, usually at rest, sandwich terns
(Sterza sandvicensis), black-headed gulls (Larus ridibundus) and lesser black-backed
gulls (Larus fuscus) may be seen.
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Chapter 3: The Biological Environment
3 .6.2 Bi rds As s oci ate d wi th F il ey B rigg and t he Be ach es of F ile y
Bay
There are a large number of birds associated with Filey Brigg and its neighbourhood and
the avian fauna is an integral component of the Bay as a whole. Large numbers of birds
can be observed, of which many are passage migrants and occasional visitors. A
comprehensive list is provided in the Filey Brigg Birds Report" (FBBR) which is
published by the Filey Bay Ornithological Group. Itemised below are some of the
commoner species together with notes on their biology:
A number of 'wading' birds can be seen on the large expanses of sand in the bay and
on the rocks of the Brigg, employing an interesting diversity of feeding habits. The
sanderling (Calidris alba) tends to run rapidly at the waters edge on the sands picking up
small animals disturbed or deposited by the waves, especially molluscs and worms, with
its short bill. These birds feed in flocks on the Brigg itself but are more
commonly found on the sandy beaches of the Bay. The following table shows the
FBBR population estimates of sanderling for 1989 and 1990:
-
Jan.
48
38
Feb. Mar.
,
Apr. May
Jun.
Jul.
Aug. Sep.
,
Oct. Nov.
Dec.
100
72
31
-
-
32
8
-
17
69
75
41
63
30
7
1
37
52
13
13
90
50
Dunlins (Calidris alpina) can often be seen feeding in flocks in the bay, probing the
muddier areas with their fairly long bill, catching worms, molluscs and crustaceans.
The table below shows the FBBR population estimates for 1989 and 1990, the figures
including birds counted on the Brigg, the beach and elsewhere in the Filey area. The very
high numbers in September and October represent passage migrants:
Jan.
Feb. Mar. Apr.
May
Jun.
176
120
40
200
250
75
Jul. Aug.
Sep.
2
5
1
110
73
15
-
4
6
48
207
305
Nov.
Dec.
448
72
145
20
35
180
The common redshank (Tringa totanus) can be seen on the Brigg feeding on
invertebrates including small mussels, the worms and amphipods which ocur in the
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Chapter 3: The Biological Environment
sediment between the mussels and the organisms which occur in crevices or under
seaweeds. A significant proportion of the population also feeds on the inter-tidal sands in
Filey Bay where they probe for small bivalve molluscs and worms such as the lugworm
(Arenicola marina) and the white ragworm (Nephtys sp.). Redshank also feed in the
fields adjoining the Bay, including the Country Park at the top of Carr Naze. Total FBBR
counts for 1989 are given below:
Jan.
76
Feb.
Mar.
Apr.
May
Jun.
Jul.
Aug.
40
46
7
1
1
23
25
,
Sep. Oct.
5
15
Nov.
Dec.
53
,
Oystercatchers (Haematopus ostralagus) can be seen probing the sand for food or
eating crustaceans, worms and molluscs off the rocks. The long chisel-shaped bill
enables them to remove limpets from the rock surfaces, open large mussels, eat large
mussels and crabs whole, or to probe the sand for molluscs and worms. The FBBR
population estimates for 1989 and 1990 suggest an overwintering population of 20-30
birds, with the high figure in August 1989 representing large numbers of birds on
migration:
Jan.
Feb.
Mar. Apr.
May
Jun.
Jul.
Aug.
Sep.
Oct.
Nov. Dec.
49
40
12
25
30
15
23
625
20
40
24
10
30
10
21
11
8
6
71
94
39
109
20
n/c
The ringed plover (Charadrius hiaticula) feeds on both rocks and the drier areas of sand
and mud by picking insects, molluscs, worms and some plant matter from the surface.
FBBR population estimates for 1990 are:
Jan.
Feb.
Mar.
Apr.
May
Jun.
Jul.
Aug.
Sep.
Oct.
10
21
5
-
6
1
3
14
8
9
Nov. Dec.
12
9
Turnstones (Arenaria interpres), as their name suggests, will turn over pebbles and bits
of seaweed to uncover sandhoppers, small worms and molluscs on the Brigg, but will
also feed on the open beach. The FBBR population estimates for 1989 and 1990 are
as follows:
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Chapter 3: The Biological Environment
Jan. Feb. Mar.
Apr.
May
Jun.
Jul. Aug.
Sep. Oct.
Nov. Dec.
53
1
70
30
40
2
17
26
54 55
10
92
40
60
21
12
20
8
37
30
70 70
n/c
4
Purple sandpipers (CaIdris maritima) feed on the rocks, in the crevices and among
seaweed capturing small crustaceans such as sand hoppers, worms and molluscs (eg. the
rough periwinkle Littorina saxitalis). Observations on a population of 40 purple
sandpipers at Robin Hood's Bay during the winter months suggested that they
consumed some eleven million rough periwinkles. Population densities of purple
sandpipers in 1989 quoted in the FBBR are shown in the table below. The high counts in
April and May represent birds of passage. There would appear to be a core
population of somewhere in the region of 30-40 birds:
Jan. Feb.
50
60
Mar.
Apr.
May
Jun.
Jul.
Aug.
Sep.
131
250
235
-
11
20
20
Oct.
70
Nov. Dec.
12
23
The rock pipit (Anthus petrosus), a member of the wagtail family, frequently feeds on
the Brigg, picking up small winkles, crustacea and insects particularly the wrack fly
Coelopa frigida. The FBBR estimated the population to average out at about 4 birds,
with 10 being recorded on the 17th December 1989. There was no change in the birds'
status in 1990 except when 15 individuals appeared around the Brigg on the 30th
October. In summer they are territorial, which may account for the fairly constant
population density.
Cormorants (Phalacrocorax carbo) and shags (P. aristotelis) are a familiar sight around
the Brigg where they swim and dive for food which consists mainly of fish (including
plaice, flounders and eels), and occasionally crustaceans and algae. They can
frequently be seen standing at the end of the Brigg with their wings held out as if to dry
them. The FBBR records the following numbers of cormorants in 1989:
Jan.
8
Feb. Mar.
Apr. May
10
Jun.
18
Jul. Aug.
n/c
and the following numbers of shags:
93
23
Sep.
Oct.
25
30
Nov. Dec.
10
5
Chapter 3: The Biological Environment
Jan.
Feb.
Mar.
2
8
n/c
Apr. May
_
11
7
Jun.
Jul.
Aug.
Sep.
11
1
6
26
Oct.
43
Nov. Dec.
56
117
Several species of gull can be seen in the area including the great and lesser blackbacked gulls (Larus hyperboreus and Larus fuscus), the common gull (Larus canus), the
black-headed gull (Larus ridibundus) and the herring gull (Larus argentatus). Kittiwakes
and fulmars visit the northern area of Filey Bay from their breeding sites on the chalk
cliffs of the Flamborough headland. The gulls will eat almost anything live or dead on
the Brigg, the beach, the waters of the Bay and local fields and they are also notorious
for their scavenging habits around sewer outfalls and refuse tips. On the Brigg itself
they have been observed consuming shore and edible crabs and fishes from rock pools.
FBBR records for 1989 indicate a population of upto 600 herring gulls early in the
year, with a maximum of 1500 being attracted by fishing activity in late November. In
1990 counts were only made in May and November yielding 200 and 400 individuals
respectively. The report suggests that 'low numbers in both winter periods possibly
reflect some reduction in fishing activity and/or catches'. Filey Bay attracts quite large
numbers of black-headed gulls, with the FBBR for 1989 recording 1000 in February
and 500 in October In 1990, 1000 were recorded in January and 1600 in February.
The common gull occurs regularly at Filey but the FBBR gives no indication as to
population size. It does, however, record upto 100 great black-backed gulls (mainly
immature) in January and April. The population fell to single figures during early
summer, although 60 had returned by July, 20 were noted in September and 60 in late
December. Lesser black-backed gulls occur in very small numbers in Filey Bay: the
FBBR records upto 4 individuals between March and November in 1989 and a similar
population in 1990.
Bar-tailed godwits (Limosa lapponica) are occasionally seen in Filey Bay, although
most individuals will only use the area as a stopping-off point on route to other sites.
The knot (Calidris canutus) is another passage migrant and occasional visitor. Both
these waders occur in small numbers except when they are on passage: for example, the
FBBR reports 406 of the latter in August 1990. Many other birds also visit the beach,
particularly in winter when food is scarce on land. Thus sparrows, rooks, crows,
pigeons etc. can be seen feeding at various times on the beach.
After the breeding season many sandwich and som e com mon terns (Sterna
sandvicensis and Sterna hirundo) pass southwards offshore and are frequently chased by
arctic skuas (Stercocarius parasiticus) which try to force the terns to drop or
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Chapter 3: The Biological Environment
disgorge their fish catch (which includes the ubiquitous sand eel). Although these birds
are mainly passing through the area on migration they do feed; the Bay is an important
're-fuelling station'. The FBBR records the absence of sandwich terns out of season in
1989 but with the following in season counts for 1989 and 1990:
Sandwich terns:
Mar.
Apr.
May
Jun.
Jul.
Aug. Sep.
Oct.
9
7
17
41
202
4
6
28
26
100
Mar.
Apr.
May
Jun.
Jul.
1
12
3
11
76
28
2
1
-
5
7
9
331
250
4
-
524
95
1
363
200
10
Aug. Sep.
Oct.
_
Common terns:
The arctic skua (Stercocarius parasiticus) is observed frequently, with the FBBR
recording 1372 individuals between July and November 1989. Other species of skua
also occur, and the following species are cited in descending numerical order: great
skua (Stercorcarius skua); pomarine skua (Stercocarius pomarinus); long-tailed skua
(Stercocarius longicauda). Looking out to sea you can sometimes detect manx
shearwaters (Puffinus puffinus) and common scoters (Melanitta nigra) passing and
occasionally sooty shearwaters (Puffinus griseus). During this period golden plover
(Pluvialis apricaria), whimbrel (Numenius phaeopus) and curlew (Numenius arquata)
are some of the waders that fly along the coast on migration.
Of the ducks frequenting the Bay two species, the eider (Somateria mollissima) and the
common scoter (Melanitta nigra) are numerically significant. They both feed by diving
from the surface for molluscs and crustacea. Eider ducks are mainly winter visitors to
Filey Bay where they can frequently be seen near to the Brigg holding crabs in their
bills, or on it as the tide floods in. The FBBR estimates for the eider population in
1989 are:
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Chapter 3: The Biological Environment
Jan. Feb.
15
11
Mar. Apr. May
27
7
8
Jun.
Jul.
8
2
Aug. Sep.
2
10
Oct.
22
Nov. Dec.
143
8
and the FBBR estimates for the common scoter population in 1990 are:
Jan. Feb.
200
1
Mar.
9
Apr. May Jun.
25
1
13
Jul. Aug. Sep.
Oct.
Nov.
Dec.
21
231
500
500
60
46
The birds inhabiting the Brigg and the Bay can thus be seen to be very important in the
ecology of the area, relying on it for food items which range from worms through to
fishes.
3.7 Biological Summary
3.7.1 Overview of Biological Features
The area surrounding Filey is characterised by a large number of different biological
habitats; the sandy beach of Filey Bay and the rocky shore of the Brigg, the cliffs and
subtidal rock of Flamborough Head and the subtidal sand, mud and gravel of the
inshore subtidal area. Each of these habitats has its own fauna and flora but these are
integrated for the area as a whole with many habitats dependent on the others. Thus if
the biology of one habitat is disturbed, this may produce a change in one or more of the
other habitats.
The study indicates that the area is important as a fish, particularly plaice, nursery area
and as an inshore feeding ground of fish and birds. There is a gradation of sediments
both along the shore and with depth and distance offshore. The subtidal area's
hydrographic features have combined to produce the rich muddy areas and moderately
rich inshore sands with a poor coarse area sandwiched in between. The muddy areas
especially support large worm and shellfish populations which provide food for fish.
Filey Beach has a characteristic fauna although preliminary study indicates it has been
affected by man's activities.
The Brigg has a rich, rocky-shore assemblage with dense populations and it has many
features unique to this coast. Although more study is required, the plankton is likely to
be rich and diverse, partly as the result of the Flamborough front.
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Chapter 3: The Biological Environment
The area under study is very important for seabirds, both for its extensive breeding
colonies, and its passage migrants. This importance has been shown to be partly due to
the presence of the high, inaccessible cliffs of the area and partly due to the presence of
the Flamborough Front with its associated abundant plankton levels.
The elevated plankton abundance may have a significant affect on the entire food web,
producing increased productivity in the higher trophic levels. In this way the presence of
the Flamborough front in summer may indirectly enable the area to support its bird and
fish populations through an increased abundance of prey. In particular, the area supports
large sandeel populations which in many cases form a dominant food source for
seabirds.
The area has an importance not only for vertebrate predators but also for invertebrate
predators and scavengers such as large crustaceans. The crabs and lobsters in turn
supporting a commercial potting fishery dependent on the availability of suitable
substratum preferred by the macro-crustaceans. In addition, there is an extensive
fishery using angling, stationary netting, long-lining and trawling which are all utilising
the biological productivity of this area.
The analysis here has indicated that the available habitats (substratum) and the water
characteristics, such as the front, produce a moderate richness of fauna and flora. To
some extent this is tempered by the overall geographical position of Filey Bay within the
British Isles. North Atlantic hydrography dictates that the north-eastern English and
south-eastern Scottish coasts are not as rich as many other parts of the British Isles.
3.7.2 Impacts on the Biological Environment
Coasts and inshore areas are subjected to many actual and potential threats which often
harm their biological well- being and functioning.
q In the case of Filey, pollution by inert solid material such as litter and fishing debris
may harm seabirds.
q Overfishing will deplete the available stocks and cause excessive trawl damage on the
seabed.
q Dredging and spoil disposal, also pollution by inert solids, may smother the
benthos and affect water quality as well as physically removing the available habitat.
q Pollution by non-inert materials such as effluent and solids from industry and
domestic waste will change communities and favour the increase of pollution tolerant
forms.
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Chapter 3: The Biological Environment
q
q
q
Mineral (oil, gas, aggregate) exploration and extraction will change the seabed and its
communities and may affect water quality.
Recreational pressure can interfere with biological habitats.
Other threats such as marina development, reclamation or other coastal engineering
are unlikely in this area but all will have a biological effect.
At present there are few deleterious effects in the Filey area. There is no evidence of
stress or pollution on the subtidal seabed although an isolated area of the beach shows
the effects of sewage discharge. The upper beach. at Reighton has shown that although
the sediments are coarse and well- washed, they are still able to be polluted through
organic enrichment by sewage discharged upstream.
There are other m inor threats in the area. The extensive subtidal rocky area at
Flamborough Head, with its rich fauna and flora, provides a good recreational diving
ground. However, this also can impose a stress on the area through damage and faunal
collection by irresponsible divers. This has been overcome elsewhere by the adoption of
voluntary marine nature reserve status.
Th is report has concentrated on the seabed as any disturbance of it, such as by
dredging, could affect its biota. Removal of sand would prevent burrowing by
sandeels during darkness, for overwintering or to avoid predators. Increased
resuspended fine material in the water column would decrease water transparency and
could thus interfere with the feeding behaviour of those fish and mammals which are
visual predators. Increased turbidity would extend over those areas adjacent to dredged
sites and could affect phytoplankton productivity and hence zooplankton populations. It
could also affect sandeel vertical migration and thus food availability for the seabirds.
Changes in seabed sediments due to dredging may also affect the invertebrate prey of
fishes.
3.7.3 Conclusions
Animal populations, from worms and small crustaceans, through larger invertebrates
such as crabs, lobster and octopus, to vertebrates such as fish and birds, and ultimately to
the mammals such as seals and porpoises to man form an interdependent food web in the
Filey area. All, at the most basic level, are dependent on the quality of the sediments and
water column. It is evident here that if the physical and chemical status of the area is
protected then the biological system will take care of itself. Similarly, that
interdependence indicates that a removal of one biological component, e.g such as by
overfishing or substratum extraction, will also affect the remainder of the system. This
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Chapter 3: The Biological Environment
chapter has provided and presented data such that the biological effects of any future
well-defined threats to the area, such as dredging or effluent disposal, can be predicted
more accurately.
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Chapter 4: The Socio-economic Environment
4. THE SOCIO-ECONOMIC ENVIRONMENT
4.1 Introduction
4.1.1 Definition of Study Area
The landward area covered by this section of the report extends from Filey Brigg in the
North to Flamborough Head in the South, thus encompassing the coastal parts of the
following Civil Parishes:
North Yorkshire County:
Scarborough District:
Filey, Reighton,
Humberside County:
East Yorkshire District:
Bempton,
Flamborough.
Where certain statistical data are used (eg. for population, employment, etc.) they
mainly refer to the whole area of the parish(es) and not only to the coastal parts. In
some instances reference may also be made to locations outside the study area.
4.1.2 Aims and Structure
The principal aim is to establish, as far as possible, the absolute and relative importance of
key sectors of the coastal economy and thereby assess the likely impact of near-shore
developments within the Filey Bay area . Although it is assumed that the most likely
developments will relate to aggregate dredging within the Bay some assessment is also
given of the possible consequences of oil and gas related development likely to affect the
area around Flamborough Head. .
Following a brief general account of the study area, more detailed attention is paid to the
main economic activities in the area - tourism and fishing - together with a resume of
other economic opportunities. Finally, there is an assecssment of the likely impacts of
near-shore development, essentially dredging, on the economic and social structures of the
study area.
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Chapter 4: The Socio-economic Environment
4.1.3 Method of Analysis
Most of the information in this section of the report is derived from interviews with
selected key persons (see section 4.6). Additional information has been obtained from
reports etc. listed at chapter 7. Except where explicitly stated, all opinions expressed in
the report are those of the author and may not be attributed to any individual informant
4.2 Description of the Area
4.2.1 General
Filey Bay describes some 20 km of coastline from the tip of Filey Brigg, trending
generally southeastwards to Flamborough Head. In the northerly part, the extensive sandy
beaches are backed by relatively low cliffs (30 m.) made of soft boulder clays; by
contrast, the southern section is dominated by high chalk cliffs rising to heights of circa
135 m. at Buckton. Filey Bay thus contains a great diversity of natural and human
habitats and, though disfigured in parts by modern tourism development, provides a
fine scenic experience which in itself forms part of the resource base upon which the
local economy is built. In recognition of the important contribution of the coastline to the
national heritage, the southern section of the Bay - from Speeton southwards - is
designated as Heritage Coast. The extreme northern part of the study area (Filey Brigg) is
a Site of Special Scientific Interest (SSSI) and the area immediately to landward forms a
Country Park. The broad tenor of the Local Plan (1989) is for the protection of the
natural amenities of the Bay, together with the sympathetic and carefully controlled
development of the tourism industry.
4.2.2 Administrative Structure
Since the reorganisation of local government in 1974, the study area has been divided
between the counties of North Yorkshire and Humberside. The 'town' of Filey was
the most seriously affected by the reorganisation, losing its independent status as an
urban district and being transferred from the former East Riding of Yorkshire to North
Yorkshire as a constituent part of Scarborough District.
4.2.3 Population Structure
The population of the parishes which make up the study area in 1981 was 8690, an
increase of 660 or 8% over the previous ten years (see table 4.1). Although detailed
results of the 1991 Census are not yet available they are expected to show a continuing
growth in the area's population throughout the 1980's. A distinction can, however, be
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Chapter 4: The Socio-economic Environment
drawn between areas of rural depopulation affecting the smaller villages and the
comp aratively strong growth of the larger centres of Filey, Hunm anby and
Flamborough. Throughout the area, population growth is essentially sustained by a
substantial in-migration, mainly of retired persons, which is sufficient to offset a
natural population decline caused by the high age structure. The proportion of the
population of pensionable age is 33% for the whole area but as high as 35.7% in Filey more than double the national average. Future population growth will therefore
continue to rely upon migration into the area induced by an attractive physical
environment and an adequate level of service provision in the larger settlements.
Table 4.1 Population Trends 1961-1981
Population
1961
Filey
4703
Rest of Area 2879
Total
7582
Population 1981
%
Change
1971 1981 1971-81 Households % Popn.
% Popn.
Pensionable
<16
Age
Years
5336 5695 +6.7
2327
16.5
35.7
2673 2997
+12.1
1157
19.6
27.8
8009 8692
+8.5
3484
17.6
33.0
Source: OPCS: Census 1981: Ward and Civil Parish Monitors.
4.2.4 Settlement Structure
Filey (pop. 1981: 5695) dominates the settlement structure and service provision of the
area. Fo llowing the arrival of the Hull to Scarborough railway in 1847, Filey
underwent planned development led by J. H. Unett, a Birmingham solicitor, from a
fishing village to a small but thriving, fashionable, middle-class resort town - an image
which its public leadership has been reluctant to relinquish. Partly because of physical
constraints, but also as a result of conscious policy, Filey escaped much of the tourism of
the twentieth century. It thus retains an image of somewhat faded gentility and its
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Chapter 4: The Socio-economic Environment
urban structure combines elements of the old fishing village (Queen Street), the elegant
early Victorian hotel development (The Crescent), some later nineteenth and early
twentieth century housing development and, finally, extensive areas of post-war
residential development to the north and west of the town. Certain features of the more
popular holiday culture of the twentieth century, which had been deliberately excluded
from the town of Filey, began to appear in particular forms elsewhere within the study
area - first with the building of the Filey Butlin's Holiday Camp to the south of the
town, which provided 11,000 bed spaces until its closure in 1984, and more recently
with the growth of large holiday villages to both south and north of the town. In this
way, Filey has managed to capitalise upon its favoured image as a quiet family resort
with safe beaches and sheltered bathing in an unstressed environment, whilst still
benefiting commercially from the presence, outside the town, of very extensive modem
holiday accommodation. This policy has, however, left Filey without certain essential
features of a successful holiday resort - most noticeably an all-weather leisure facility.
The only other minor centres are the former agricultural villages of Hunmanby and
Flamborough now inflated by the influx of retired and commuter populations. The
smaller villages (Bempton, Speeton and Reighton) lack anything more than a bare
minimum of service provision though some of the larger 'holiday villages' may provide
seasonally available retail and other services intended for their client populations. For
most higher order services, including formal leisure and entertainment, the resident and
visitor populations of the study area look to the larger urban centres of Scarborough
(pop. 46,000) and Bridlington (29,000) which are situated only short distances beyond
the boundaries of the study area and are easily accessible by road and rail.
4.2.5 Employment Structure
In common with many small holiday resorts, the economic activity is narrowly based and
subject to strong seasonal variation: unemployment is high, especially in the winter season.
The study area is designated as part of the Rural Development Area of the respective
county authorities. Most of the employment within Filey is related directly or indirectly
to the tourism and fishing industries, which are discussed in detail below (sections 4.3
and 4.4). Commercial businesses within the town are mainly small family concerns
creating relatively little non-family employment. By contrast, the large 'holiday villages'
elsewhere along the coast generate substantial demands for seasonal employment which
cannot be fully satisfied from within the local labour pool.
Other employment opportunities within the area are scarce. Not surprisingly local
interests have restricted the development of significant manufacturing employment for
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Chapter 4: The Socio-economic Environment
fear that it would prove incompatible with the resort image. Apart from a makings in
Flamborough and a range of small industrial firms on the estate at Hunmanby, most of
the jobs outside the service sector and the fishing industry are in agriculture - a
nationally declining sector of the economy. Significant numbers commute to work
outside the area in the local engineering works at Gristhorpe or in the urban centres of
Scarborough and Bridlington.
4.3 Tourism
4.3.1 Introduction
Tourism is the most important single economic activity within the study area. It is
responsible, directly or indirectly, for the largest share of employment opportunities
and income generation. It imprints its particular characteristics on the area in markedly
different ways. Planning policies are designed to protect the industry's resource base and
to enhance its image and reputation.
For the region as a whole, the basis of visitor appeal is firmly located in the natural
amenities of the Yorkshire Coast, stretching from Staithes in the North to Flamborough
in the South, and its attractive rural hinterland. At specific locations along the coast,
most notably at Scarborough and Bridlington, the natural amenities have been
supplemented by the development of man-made leisure facilities in order to broaden the
visitor appeal.
The attraction of Filey Bay, however, is based almost exclusively upon the area's
natural resources: the spectacular scenery afforded by the broad sweep of the Bay; the
wide expanse of 'golden' sandy beaches and the safe, sheltered bathing waters in the
northern part of the Bay; and the fascination of one of Britain's largest mainland seabird
colonies in the southern part. With the exception of one major post-war development,
little has been done to 'enhance' the tourism appeal of the area through the building of
man-made facilities other than in accommodation. Nonetheless, the development of
tourism has given rise to certain paradoxes and tensions within the area.
4.3.2 National and Regional Trends
The hey day of the seaside resort in Britain came to an end in the 1970s with rising
disposable incomes, increased personal mobility, longer holiday leave and greater
opportunities for overseas holiday making through the growth of charter flights and
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Chapter 4: The Socio-economic Environment
package holidays. The British holiday resort was unable to meet the demand for
sunshine and adventure at low prices.
Although the number of leisure trips has increased as a reflection of rising car
ownership, the proportion of seaside destinations has fallen from around 30% in the
early 70s to 23% in the late '80s; the number of overnight holiday stays on the coast
declined even more sharply from around 180 m. to 115 m.; but the volume of
expenditure, at current prices, increased very considerably from £475m in 1973 to
£1845m in 1988, partly in line with inflation but also reflecting the changing nature of
the seaside holiday experience.
Today, the seaside resort accounts for only a quarter of all tourism trips and a third of
domestic tourism spending within Britain. There have been some signs of recovery in
the domestic seaside holiday industry in the last three or four years and further growth is
expected over the next few years - partly as a result of the failing fortunes of the package
holiday industry abroad and also as a consequence of greater innovation within the
domestic sector.
But the changes which have affected the seaside holiday industry were much more
profound than a simple decline in the volume of visitors and an increase in per capita
expenditure. The seaside resort was being used in a different way: as a destination for
day trips and as a venue for short breaks especially at weekends and out of season, in
addition to the traditional longer family holiday.
Even more critical is the changing nature of accommodation with movement away from
the traditional serviced sector (hotels and guesthouses) and towards unserviced
accommodation in the form of caravans and apartments. Thus the industry, in order to
survive let alone expand, was compelled to adapt to major shifts in the pattern of visitor
demand. The industry in Filey Bay has responded in very different ways to the
pressure for change.
4.3.3 Tourism Infrastructure: Visitor Accommodation
One of the principal contrasts within the study area lies in the provision of visitor
accommodation in the town of Filey and in the surrounding 'rural' areas. But any
attempt to arrive at reasonably accurate estimates of visitor accommodation is fraught
with difficulty. Only a proportion of the registered holiday businesses advertise
through the official accommodation lists (and an even smaller proportion are members
of the local Tourism Association). A much larger part of both serviced and unserviced
105
•
Chapter 4: The Socio-economic Environment
accommodation occurs in premises with fewer than six bedrooms and is therefore not
required to register for purposes of business rating; in many such instances, visitor
accommodation is unlikely to be the sole or even main source of income.
The last detailed survey of Filey's visitor accommodation was conducted in 1978,
when a total of 4,500 bed spaces was recorded within the urban area. Since that date
considerable changes have occurred. But even in 1978 only 14% of Filey's tourist
acco mmodation was in the traditional serviced sector; 39% was in rented
accommodation (flats, chalets, houses) and 47% in static and touring caravan sites and
tent pitches.
Time has taken its toll of serviced accommodation. The downward trend in hotel
accommodation began with the closure of the larger hotels at key sites within the town,
including the Victoria, Royal Crescent and Hylands all on the Crescent, and similarly in
the area fronting the sea (The Beach). It has continued with the conversion of smaller
hotels and guesthouses to flats and nursing homes in the inner part of the town. The
stock of serviced accommodation has fallen even below the 1978 level; its relative
scarcity represents a constraint upon the growth of the town's tourism industry and
there is unlikely to be much expansion in the future. There is now a noticeable lack of
large, highly rated hotels and, therefore, of even the smallest conference facility; today
the largest hotel in Filey has less than 20 bedrooms and is unclassified.
Much of the holiday accommodation within Filey is now unserviced - flats, caravan sites
and camping facilities. But a very much higher proportion of the rural area's
accommodation is in the unserviced sector. Excluding touring caravan sites on the edge of
Filey (adjoining the Country Park), at Muston and at Hunmanby, there are several very
large holiday villages, comprising a mix of fixed and mobile caravan pitches and chalet
accommodation, along the coast. Four, all now under the management of Haven
Holidays (Rank), lie within a 5 km. radius of the town; they have recently undergone a
major programme of capital investment to expand and improve accommodation and
facilities and are thus able to offer a modern holiday experience, still based on the
natural amenities of Filey Bay, to a maximum of 20,000 visitors. Their occupancy
covers approximately 22 to 24 weeks of the year though the sites remain open from
March to November mainly for the private use of caravans by those who own holiday
homes on the site. All told, unserviced accommodation in the study area probably
provides for around 22,500 visitors. The provision was once very much greater with
Filey Butlin's adding a further 11,000 bed spaces upto its closure in 1984.
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Chapter 4: The Socio-economic Environment
Table 4.2: Estimates of Serviced Accommodation, Filey 1991.
Number
Bed Spaces
Rooms
Hotels (listed)
Guesthouses (estimate)
Bed + Breakfast (estimated)
Total (estimated)
7
80
200
20
100
200
25
50
100
52
230
500
4.3.4 The Season
On a fine summer's day, Filey's day-time population may well exceed 25-30,000, but
this is a relatively short-lived experience. Although Filey's hoteliers seem reasonably
satisfied with the length of the season, in effect the holiday period is limited to a fairly
short summer season of circa 12 weeks from mid-June to mid-September, largely
coincident with school holidays, when occupancy rates exceed 75%. Indeed only a
small proportion of both serviced and unserviced accommodation (together with
restaurants and cafés) is available all year round. In recent years, there has been some
increase in bookings in the shoulder months (May - June, September - October) and in
the off-season, usually for retired persons together with a growth in weekend breaks.
An encouraging sign for the lengthening of the season is the recent application from one
of the largest holiday villages to extend its period of opening to an 8 month run from
March to October. The marked seasonality of the holiday industry has a severe impact
on earnings in the retail trade.
4.3.5 Tourism Infrastructure: Amenities
One reason for the relatively short holiday season and one of the factors which helps to
shape the visitor profile (see section 4.3.6 below) is the absence of major
107
Chapter 4: The Socio-economic Environment
entertainments and all-weather facilities. At present the town of Filey is remarkable for
the absence of any sizeable man-made attraction - the result both of a lack of
opportunity and a considered lack of will within the town. Almost all the amenities are
open-air (beach, Country Park, putting greens, miniature golf, competition golf course,
riding, tennis, bowls, etc.): the only indoor provision is the Small Concert Hall and the
Sun Lounge where occasional concerts are held. As a result there is a large daily
movement of visitors in the summer season to the neighbouring resorts of Bridlington and
Scarborough, especially from the holiday villages. The holiday villages represent a very
considerable capital investment In addition to accommodation in chalets and fixed
caravans, they provide a wide range of entertainment, leisure, shopping and service
facilities for the resident holiday maker.
The holiday industry of Filey Bay thus rests fundamentally on its natural amenities -good
beaches, safe bathing, fine scenery - and the occasional opportunities for
essentially informal outdoor recreation: walking, riding, sailing, fishing, windsurfing and,
in the inland areas, hang gliding. The excellent Filey beach lends itself particularly well to
sand-yachting and recently failed only narrowly to be selected as the site for the European
Championships.
There are no plans to develop the tourism infrastructure within Filey, although there are
some expressions of need for a small-scale, all-weather facility principally for young
children. The only prime site within the town awaiting development (Deep Dene) is most
likely to be used for residential development. Outside the town, the site of Filey Butlin's
camp, abandoned in 1984, has been a focus of speculative interest although none of the
plans, including the most recent proposal for a fully serviced 'retirement village' with
hotel and golf course, has made substantial progress. Occupying a prime regional site
urgently in need of renovation, its development could greatly enhance the tourism
infrastructure of Filey Bay.
4.3.6 Visitor Profile
Gaps in the tourism infrastructure of Filey and district help to define the visitor profile
quite precisely. The absence of large-scale entertainment facilities (dance halls, discos,
amusement parks, etc.) reduce the area's appeal to the teenage and young adult markets
and, in a similar manner, the absence of large hotels constrains the industry's customer
base in social class terms. Thus, most of the resident visitors will be drawn from
young families with children and the retirement age group in the lower income groups
C2, D and E though there are some important seasonal variations. Family groups
predominate in the peak summer season and retired persons in the shoulder months.
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Chapter 4: The Socio-economic Environment
Some broadening of the profile may occur in the off-season when Filey attracts the
outdoor leisure interests from marginally higher social groups.
In general, peak season accommodation is occupied by weekly or, less frequently,
fortnightly bookings. Although Filey still draws heavily on the traditional regional
markets of West and South Yorkshire, there has been a noticeable widening of the
catchment area to include the East and West Midlands as well as North West and North
East England and a scattering of visitors from the rest of England and Wales. Three
quarters of Filey's staying visitors arrive by car; the rest (mainly pensioners) by rail and
coach. Day visitors are drawn from a broadly similar section of the population but, not
surprisingly, from a more strongly regional catchment in West and South Yorkshire.
All visitors are attracted to Filey by its natural amenities and/or as a quiet, safe and
stress-free base for touring the Yorkshire coast. For the summer family holiday the
beach and associated safe bathing are clearly the principal attractions. The Filey holiday
experience may become habitual, with many families returning regularly for their week
by the sea.
4.3.7 Employment and Income Generation
4.3.7.1 General
Scarborough District Council's tourism department has recently developed a computerbased Tourism Economic Activity Monitoring Programme' (TEAMP) which provides
estimates of expenditure and employment generated by the tourism industry by local
areas. The information is readily available for Filey but there are certain difficulties in
allocating the appropriate share of values for those parts of the study area which lie in the
neighbouring East Yorkshire Borough of Bridlington. As a very crude approximate for
the rural parts of the study area, 50% of the values for Scarborough Rural have been
allocated to Filey Rural and no additional values have been included to cover the
Bempton and Flamborough parishes in the South of the study area.
The model is based on an analysis of visitor accommodation, occupancy rates and
estimates of total visitor numbers combined with a series of standardised expenditure
and employment ratios. Thus, although the pattern of employment and expenditure will
reflect the different accommodation mix in the different local areas, it assumes that
expenditure and employment arise in the same locations as the accommodation
provision. This is demonstrably not the case in the study area where there are strong
daily flows of visitors between the place of overnight stay and the concentration of
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Chapter 4: The Socio-economic Environment
amenities. The results of the computer programme will, however, suffice to give a
broad indication of the industry's capacity to generate expenditure and employment.
4.3.7.2 Employment
There is likely to be a significant difference in the employment generated by the tourism
industry in the urban and rural parts of the study area. In the former, most tourismrelated businesses are small family concerns offering little regular employment outside
the family: such jobs as are created can be quite easily filled from within the town's
significant jobless population. By contrast, in the rural areas the large holiday villages
probably develop a far higher demand for seasonal labour which cannot be readily be
met from local resources.
According to the TEAMP, in 1989, tourism generated a total of 382 jobs in Filey
(mainly in the accommodation, food and drink sectors) and a total of 3,860 jobs in
Scarborough Rural which would equate to 1,930 jobs in the rural parts of the study
area and so give a total of circa 2,310 jobs for the study area as a whole (see table 4.3).
4.3.7.3 Expenditure
The patterns of expenditure will tend to vary markedly between local areas according to
the precise relationship between accommodation and amenity provision. Thus, in
reality, the rural areas which provide abundant accommodation but relatively little by
way of amenities will tend to have lower receipts than areas which combine substantial
accommodation, retail and amenity provision. The results of TEAMP, which take little
account of the leakage of expenditure from the study area to the major resorts of
Scarborough and Bridlington, indicates a gross expenditure of £28.9m in 1989, made up
of £4.6m in Filey town and £24.3m in the rural areas (see table 4.4).
Despite the imperfections of the model in providing accurate local estimates of
expenditure and employment and the complications of fitting the data to the study area, it
is clear that the tourism industry is responsible for creating substantial revenue
(£29m) and employment (2,300 jobs) in the study area.
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Chapter 4: The Socio-economic Environment
Table 4.3 : Tourism: Employment Generation 1989.
Number of Jobs:
Accommodation
Filey
Rest of Area
Total
123
866
989
%
43
Food and Drink
114
375
489
21
Leisure and Recreation
21
53
74
3
Shopping
32
178
210
9
Transport
5
21
26
1
87
437
524
23
382
1930
2312
Indirect Effects
Total
100
Based on: Scarborough Borough Council: Scarborough Tourism Economic Activity
Monitoring Programme, 1990.
111
Chapter 4: The Socio-economic Environment
Table 4.4 : Tourism: Generation of Expenditure, 1989.
£ 000's :
Filey
Rest of Area
Total
%
Accommodation
1245
8752
.
,
35
9997
Food and Drink
929
3055
3984
14
Leisure and Recreation
163
411
574
2
Shopping
943
5247
6190
21
Transport
148
617
765
3
Indirect Effects
1178
6202
7380
25
Total
4606
24284
28890
100
Based on: Scarborough Borough Council: Scarborough Tourism Economic Activity
Monitoring Programme, 1990.
4.3.8 Summary and Evaluation
Filey Bay forms an integral part of the regional tourism infrastructure, offering a
contrasting and complementary experience to that available in the more highly
developed resorts of Scarborough and Bridlington. Two distinctive sectors of the
tourism industry are represented within the area:
(a) Filey Urban: a small resort town with a narrow range of traditional visitor
accommodation and limited amenities;
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Chapter 4: The Socio-economic Environment
(b) Filey Rural: the extensive stretch of coastline south of the town with very little
hotel and guesthouse accommodation but a major provision of permanent and
touring caravan pitches together with some permanent chalet accommodation in the
form of modernised 'holiday villages'.
Thus, although Filey is the only resort town within the area and also the nearest urban
service centre for the outlying rural populations, most of the holiday accommodation lies
outside the built-up area of the town.
Despite the small scale of tourism development (other than in the accommodation
sector) and the brevity of the holiday season, tourism generates considerable revenues
(circa £29m) and employment (circa 2,300 jobs) for the area.
The principal attraction for the visitor lies in the natural resources of landscape, beach
and bathing waters. The beach, in particular, is a highly valued asset. Any threat of
permanent damage to the beach at Filey would have very serious repercussions for the
tourism industry. It would undermine the carefully nurtured image of Filey and
substantially weaken the product that Filey's holiday making industry has to offer. It
would put at risk a substantial number of jobs and a large share of local revenue - an
impact that would reverberate throughout the local economy. In a very real sense, the
beach at Filey represents the area's major source of wealth.
4.4 Fisheries
4.4.1 Introduction
The significance of Filey Bay for fisheries is indicated in two ways:
a)
b)
as an important nursery ground for 0-year plaice and also (according to local
fishermen) for sole, though this claim is not substantiated by MAFF scientists;
as an important inshore commercial fishing ground for whitefish (notably cod and
sole), salmon and trout and shellfish (lobsters and crabs) which is exploited by
fishermen from Bridlington, Filey and Scarborough and from much smaller bases at
North and South Landings.
Both aspects of the fishery depend upon the maintenance of a delicate equilibrium in the
conditions of the sea bed within Filey Bay. A combination of rock, sand and shingle is
responsible for the richness and diversity of the Bay's fisheries.
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Chapter 4: The Socio-economic Environment
Along the East Coast, fishing is in decline mainly because overfishing has reduced
stocks o f popular commercial species in the North Sea to the level of being
'dangerously overexploited' and because attempts to conserve and rebuild the stocks
have involved the imposition of restrictive quotas. The situation has been made worse by
high interest rates on borrowed capital for the building and equipping of modern fishing
boats. As a result, the numbers of fishing boats and active fishermen have fallen
sharply over the years and the structure of the industry is characterised by an aging fleet
with very few newly built boats.
4.4.2 Fishery Regulations
In general, the area within the 12 mile limit is at present reserved for fishing by coastal
state vessels except where special arrangements are made to allow other EC member
states with 'historic preferences' to fish within the 6-12 mile zone. Such preferential
arrangements have been made in respect of Dutch fishermen along the Yorkshire coast.
The area within 3 miles of the coast, reserved for inshore vessels, is subject to
regulation through bye-laws administered by the Sea Fisheries Committee (SFCs).
Within the study area, the North Eastern SFC has defined trawling exclusion zones
within Filey Bay "between a line drawn true East by South-half-South from the extreme
South end of the Filey Sea wall and a line drawn true North East from the coastguard
Station at Speeton" (see fig. 3.28).In practice the exclusion zone is continued to
Flamborough Head and beyond. This definition is currently under review by the SFC.
No other specific regulations apply within the study area.
4.4.3 Filey
Of the three fishing centres along the Yorkshire coast, Filey is naturally the most
dependant on the fisheries within the area of the Bay - not only for reasons of
geographical proximity but also because the absence of any harbour facilities at Filey
restricts the type of boat to the traditional Yorkshire coble with its twin keel design to
permit hauling by tractor across the beach at all states of the tide.
4.4.3.1 The Fleet
The fleet at Filey comprises 12 fishing cobles all under 10 m. and, therefore, outwith the
system of individual quotas imposed through MAFF. These work as 'dayboats' with
speeds of circa 6 knots and an operational range of upto 20 miles offshore. At the time
of the survey there were only 9 cobles actively fishing and one sea-ready boat expected
to participate in the fishing later in the year. Associated with these larger cobles,
there are approximately the same number of potting cobles, circa 5 m. in length,
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Chapter 4: The Socio-economic Environment
used for nearshore work with crabs and lobsters. There are a further three boats
involved in summer angling trips operated by retired fishermen or non-fishermen. At
North Landing, towards the southern end of the Bay, there are three more cobles
working gear both summer and winter.
4.4.3.2 The Fisheries
All the fishing units present in Filey are active throughout the year. It is estimated that
Filey boats will be fishing for between 45 and 48 weeks of the year with the slackest
period occurring in the first quarter of the year. To sustain a year round fishing activity it
is usually necessary to combine several different seasonal fisheries:
a)
Potting for crabs and lobsters is the principal activity earning upto 60% of
the value of the total annual catch. In most cases the season begins in March and
lasts through to the end of October though fishermen may continue to shoot their
pots upto Christmas in mild winters and at least one Filey man is engaged in year
round potting. Potting is an unregulated fishery, except for restrictions on
minimum landing sizes: fishermen can shoot their pots wherever they wish
according to custom, usually within three miles of the shore in the area between the
northern side of Filey Brigg and North Landing to the East of Flamborough Head.
Potting is traditionally a daily activity with the pots hauled and reshot every
twenty-four hours: modern equipment, however, permits the pots to remain in the
water for upto 4 days without damaging the catch.
b)
Salmon Netting is the only externally regulated fishery with licences defining
the period of the fishery and the size of the net granted annually by the National
Rivers Authority. The 12 week fishing season, usually lasting from May to
August, overlap that of the lobster potting. Drift nets upto 400 m. in length and
anchored to the seabed are visited daily and must be removed for a period of two
days each week to allow for the passage of some of the migratory salmon.
Salmon netting is usually conducted from the smaller cobles while pots are
worked by two men from the larger boat. At present 14 licences are available to
Filey fishermen though only 12 were operative in the 1991 season. The local
salmon fishery will be very seriously affected by the government's decision to
phase out the licensing of drift nets along the North East Coast of England.
c)
The end of the potting season in October usually marks the start of the autumn
fishery for whitefish (cod). Lining, the traditional method of taking cod and
ensuring a high quality, conservation-friendly fishery, is now highly restricted
115
Chapter 4: The Socio-economic Environment
largely because of its very labour-intensive form. It requires a 'shore crew' of
two or three persons to skein the mussels (bait), attach the snoods to the line and
bait the hooks. There is a scarcity of labour willing to undertake such tasks,
formerly done by the wives and daughters of active fishermen with the help of
retired and physically incapacitated fishermen. The scarcity of labour has largely
compelled a switch to fixed netting (gill nets and trammel nets) which can be
conducted throughout the year but is mainly concentrated in the autumn and
winter months. Some jigging (hand-lining) for cod also takes place off wrecks
throughout the year.
4.4.3.3 Employment and Earnings
It is estimated that there is a total of between 25 and 30 men employed full-time at sea
and a slightly larger number engaged onshore in the maintenance and repair of boats and
gear, preparing bait and preparing the catch for sale, though many of the shore jobs are,
in fact, part-time. A recent survey for Scarborough Borough Council gives significantly
higher figures for employment both at sea (54) and onshore (72) with a further 20 jobs
arising in indirect employment. It is difficult to see how these estimates square with the
existing number of boats fishing from Filey or with current catch values. Most of
the catch is sold at fixed prices to merchants who truck the fish to markets within
the UK or, in the case of lobsters, to the near continent. Some of the catch is sold locally
and one or two Filey fishermen have their own retail outlets in the town.
The tonnage and value of landings for 1988, 1989 and 1990 are given in table 4.5.
Although the volume of landings fell over the three years by 13%, the value of the catch
has risen by more than a third, reflecting the increasing scarcity of supplies of prime fish
but more particularly the strong growth in catches of shellfish which command high
unit prices. Over the three years the share of total value held by crabs and lobsters rose
from 30% to 60%.
Assuming a total of 11 units operating in 1990, the average gross earnings per unit was
£42,500; the customary allocation of the catch value, after expenses, allows 50% for
equal distribution among the crew. With between two and three men per fishing unit,
average earnings from fishing would fall well below £10,000 per man.
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Chapter 4: The Socio-economic Environment
Table 4.5 : Fisheries: Landings and Values 1988-90: Filey.
Value:
£ 000's
Vo lume:
tonnes
1988
1989
1990
1988
1989
1990
236
152
152
243
159
191
-
-
115
106
-
-
267
349
Demersal
Pelagic
-
Crabs and Lobsters
Other Shellfish
Total
72
-
308
138
-
290
-
249
277
-
408
-
468
Source: North East Sea Fisheries Committee.
4.4.3.4 Evaluation
The fishing industry at Filey provides direct full- or part-time employment for between 50
and 60 persons and grosses revenues of circa £0.5 m. per annum. It is wholly dependant
on the maintenance of the fishing grounds throughout the area of Filey Bay. Among the
main concerns expressed by local fishermen arising from possible aggregate dredging in
the Bay are:
a)
the disturbance of fishing activities during the period of dredging;
b)
the sterilisation of important whitefish and shellfish grounds both during and after
dredging operations;
c)
the destruction of the valuable plaice (and sole) nurseries within the Bay;
d)
a reduction of the natural protection afforded to the northern part of the Bay by the
30 m. submarine ridge which helps to reduce the 'surf and so allows boats to move
easily on and off the beach at all conditions of the tide and most times of the year;
117
Chapter 4: The Socio-economic Environment
e) disruption to the landing facility at Filey: if the sand beach at the Coble Landing were
removed to uncover the under lying boulder clay, tractor hauling of boats in and
out of the water would become difficult if not impossible. On a number of
occasions in recent years, storms have uncovered the boulder clays lying c. 0.5
m. below the sands at the Coble Landing; although remedial action has been
necessary in the form of dumping stones to form a temporary bed area, the beach
has quickly reestablished itself from supplies within the Bay.
Overall, therefore, dredging is seen as a serious threat both to the basic resources of the
fisheries and to existing operational systems.
4.4.4 Bridlington
The area around Flamborough Head is renowned as one of the most prolific inshore
grounds off the east coast of England but also recognised as a difficult area to work
because of variations in tidal currents, wrecks, etc.. It is exploited mainly by the
Bridlington fleet and by boats based at the North and South Landings. The Bridlington
fleet comprises 20 keel boats, mostly over 10 m., which form the offshore section of
the fleet operating as dayboats or as 'trippers' on voyages upto 10 days in length; 20
inshore boats - cobles or fast launches - usually under 10 m. and combining potting and
netting as at Filey; and 28 part-time angling cobles combining netting in winter with
angling and pleasure trips in the summer. Altogether employment at sea is estimated at
around 160 man years with an equivalent number onshore. Although there are good
shellfish grounds to the south of Flamborough and an abundant inshore fishery for sole to
the south of Bridlington, almost all of the Bridlington fleet is dependant in some
measure on the grounds off Flamborough Head.
The keel boats, engaged mainly in trawling for whitefish, account for a significant
share of the total landings of around 2400 t. valued at £3.34m in 1990 (see table 4.6).
One third of landings arise in the third quarter of the year (July to September). Unlike
Filey, where shellfish account for a very high proportion of the gross earnings, at
Bridlington it is the demersal fisheries which make up 85% of landings by value.
Nonetheless, it is estimated that the inshore fisheries account for perhaps as much as
60% of all landings made by the Bridlington fleet.
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Chapter 4: The Socio-economic Environment
Table 4.6 : Fisheries: Landings and Values 1988-90: Bridlington.
Vo lume:
tonnes
1988
4001
1989
Val ue: £ 000's
2392
1990
2222
1988
3716
1989
2476
1990
2824
104
410
1
24
71
0
Crabs and Lobsters
222
187
156
348
391
481
Other Shellfish
29
109
55
14
54
39
2434
4102
2992
3344
Demersal
Pelagic
Total
4356
3098
Source: North East Sea Fisheries Committee.
4.4.5 Scarborough
Scarborough's fishing industry conforms in broad outline to the pattern of activity at
Bridlington though with an even stronger emphasis upon whitefish which accounted
for 93% of gross earnings in 1990. The 20 keel boats over 10 m. make up the bulk of
the catching power. Of these, 5 of the larger boats make trips of 5 or 6 days fishing the
central and northern North Sea in summer but converting to dayboats in the winter
trawling the Yorkshire coast southwards to Flamborough Head. The remaining keel
boats make shorter trips (upto 36 hours) in summer and fish as dayboats in winter.
The inshore fleet, comprising 20 full-time cobles and 20 part-time cobles work the area
from Robin Hood's Bay in the north to Filey Brigg in the south, potting during the
summer season and netting for cod in winter. Very little salmon netting is undertaken by
Scarborough boats. Some of the inshore boats also engage in wreck fishing, using
special gear. As with the Bridlington fleet, almost all Scarborough boats will fish the
waters off Filey Bay at some period of the year. In total landings at Scarborough have
fallen by a third in volume and by 13% in value since 1988 (see table 4.7). As at
Bridlington, one third of landings occur in the summer months (July to September).
Fishing provides for some 150 man years employment at sea and a somewhat larger
number on land: unlike Filey or Bridlington, Scarborough has its own daily auction
market with fish destined either for local consumption or for the major inland markets.
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Chapter 4: The Socio-economic Environment
Table 4.7 : Fisheries: Landings and Values 1988-90: Scarborough.
Value:
Vo lume:
tonnes
1988
4001
1989
104
Crabs and Lobsters
£ 000's
1990
2222
1988
3716
1989
2476
1990
2824
410
1
24
71
0
222
187
156
348
391
481
Other Shellfish
29
109
55
14
54
39
Total
4356
2434
4102
2992
3344
Demersal
2392
Pelagic
3098
Source: North East Sea Fisheries Committee.
4.4.6 Overview
The waters of Filey Bay and the adjoining areas of Filey Brigg and Flamborough Head
support an important inshore fishery exploited by the fleets of Bridlington, Filey and
Scarborough. All told the fishery yields an annual revenue well in excess of £1.0m and
contributes in varying degree to the employment of some 350 persons at sea and a
roughly similar number onshore. Most fishermen are active throughout the year but
there is some seasonal concentration of effort and earnings especially at Filey where the
summer crabs and lobsters dominate the pattern of landings. Although damage to the
fishing grounds within Filey Bay would be of greatest concern to the Filey fishermen, it
would also have a major impact on those fishing from Bridlington and Scarborough. At
its worst, dredging for marine aggregates could totally destroy the Filey industry and
seriously displace fishing effort at the other ports, putting added pressure on stocks in
adjacent waters. It should, however, be pointed out that there is a comprehensive Code
of Practice for Extraction of Marine Aggregates (AT H), which allows for close
consultation between the Crown Estates Commission and the fishery and dredging
industries in the event of licenses for prospecting and extraction being granted. The
Code of Practice is currently under review.
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Chapter 4: The Socio-economic Environment
4.5 As s es s men t of Imp acts
Any assessment of the impact of nearshore developments upon the economic and social
conditions of Filey and the surrounding areas must focus on two particular aspects tourism and fishing - which together make up a significant proportion of local
employment and revenue. For tourism, the potential risks arising from the dredging of
aggregates within the area of Filey Bay are obvious. The beach, a natural focus for the
summer holiday maker, could be permanently damaged if the supply of sand for the
renewal of the beach is removed. The beach at Filey is probably the resort's most
important single amenity and destruction of the beach would tear the heart out of Filey's
summer holiday industry. Similarly, the removal of the natural, submarine ridge that
shelters the waters of the Bay from heavy seas would both expose the beach to more
extensive erosion and modify the reputation for safe bathing within the Bay. Increased
erosion would further undermine the sea wall which protects Filey town and also
supports a modest range of low-key amenities.
The impact of nearshore developments upon the fishing industry are rather more a
matter for speculation because little is known of the long-term impact of aggregate
dredging on the marine ecosystem and the habitats in which the fish live. This is an
area where further research is essential to establish the facts and allay prejudices. There
seems little doubt, however, that the local fishing industry could suffer as a
consequence of disruption to fishing operations, longer term damage to the fishing
grounds and, specifically, increased difficulties in hauling boats on and off the beach if
the sand is removed and the underlying boulder clay substrate is permanently exposed.
The repercussions from nearshore dredging operations could extend beyond the more
im med iate consequences for the tourism and fishing industries. Any loss of
employment and revenue from these two sectors would have serious implications for
the town's service economy which at present relies very heavily upon seasonal receipts
from summer visitors. At present the opportunities to replace lost jobs elsewhere in the
local economy are virtually non-existent.
Damage to the area's natural environment and to the service economy would render it
much less attractive to the large inflow of retired persons which presently account for
almost a third of the population and which largely sustain the area's demographic
development.
In short, the ramifications arising from damage to Filey Bay's natural resources would
penetrate the whole of the area's economic and social structure with seriously
121
Chapter 4: The Socio-economic Environment
detrimental effects. Significantly, there are no foreseeable local benefits arising from the
dredging operation: the operations would be conducted entirely at sea and the 'harvest' of
aggregates landed at ports outside the study area for use in the construction industry in
north east England.
4.6 List of Consultees
Mike Carter: Chairman, Filey and District Tourism Association (and Don
Driscoll, Secretary).
Mrs. Freda Coultas: Chairperson, Filey and District Chamber of Commerce.
David James: Director of Tourism and Amenities, Scarborough Borough
Council.
Fred Normandale: Chairman, Scarborough Inshore Fisherman's Society.
George Traves: Chairm an, Bridlington and Flamborough Fisherm an's
Association.
Bob Watkinson: Member, North Eastern Sea Fisheries Committee.
Ray Williamson: Forward Planning, Department of Technical Services,
Scarborough Borough Council.
Mrs. Susan Wilson: Chief Executive, Yorkshire and Anglia Fish Producers
Organisation.
122
Chapter 5: Conservation
5. CONSERVATION
5.1 Introduction
Filey Bay, defined as the stretch of coastline from Filey Brigg in the north to
Flamborough Head in the south, is an area of outstanding importance for wildlife,
landscape and amenity. Almost all of the coastal area is afforded protection either
through designation under national conservation policies or through local planning
policies.
The area owes its conservation importance, at least in part, to the significance of
Flamborough Head in the general hydrographic and biological character of the western
side of the North Sea. These characteristics are described more fully elsewhere (see
chapters 2 and 3). Briefly, a strong frontal system, separating the permanently wellmixed waters of the southern North Sea from the seasonally stratified water of the
northern North Sea, develops close inshore in summer giving increased plankton
growth and secondary productivity in the areas around Flamborough Head. As a
result, the coastal waters are important spawning and/or nursery grounds for fish and
rich feeding areas for the nesting and young seabirds which occupy sites on the cliffs
around Flamborough Head.
5.2 Nature Conservation
The cliffs around Flamborough Head contain some internationally important colonies of
seabirds, totalling around 250,000, including England's largest puffin colony, the only
mainland gannetry in Britain and one of Europe's top breeding sites for kittiwakes,
with around 80 000 pairs, together with large numbers of razorbills and guillemots.
Although these birds spend much of their life out at sea, they make intensive use of the
inshore areas for feeding their young. The seabirds are resident on the cliffs from
February to October with the breeding season, differentiated for different species,
lasting from May until August or even as late as October. The fledged birds also spend
time feeding in the inshore areas before leaving for the open seas and several species
are present in the area throughout the year.
The sheltered waters of Filey and Bridlington Bays are also important wintering areas
for sea ducks and for other seabirds during rough weather.
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Chapter 5: Conservation
The danger from nearshore dredging for sands and gravels is the disturbance and
eventual destruction of the benthic communities in inshore waters which provide the
major food supplies for the breeding birds and their fledglings, thus making potentially
very serious inroads into the breeding success. This could culm inate in the
abandonment of what is one of the finest breeding sites in Europe.
Two areas have been identified by the Nature Conservancy Council (now English
Nature) as Sites of Special Scientific Interest (SSSIs): Flamborough Head, first notified in
1952 and renotified in 1986 under section 28 of the Wildlife and Countryside Act 1981,
covering a total of 315 hectares, extending over 8 km of coastline from Reighton Sands
to North Sands on the edge of the built-up area of Bridlington; and Filey Brigg, a smaller
site occupying 28 hectares, first notified in 1985. Detailed specifications of both sites
are given at Appendix C. At Flamborough the level of environmental protection
goes further: the area of Bempton Cliffs fulfils the criteria for designation as an Special
Protected Area (SPA) under the terms of the European Community Directive 79/409/EEC
on the Conservation of Wild Birds. Parts of Bempton and Buckton Cliffs are owned and
managed by the Royal Society for the Protection of Birds, who claim that the reserve is
visited by circa 95,000 people a year.
5.3 Landscape and Amenity Conservation
The whole extent of Filey Bay affords opportunities for the enjoyment of outstanding
coastal scenery and of public access along the coastal footpaths. Such is the importance
of the southern part of the Bay that the 20 km. length of chalk cliffs from Reighton to
Sewerby was designated in 1979 as Heritage Coast. The designated area, embracing
about 330 ha. of cliff-top land is administered by the Countryside Commission in
association with the relevant local authorities (Humberside County Council, East
Yorkshire Borough Council, North Yorkshire County Council and Scarborough
Borough Council). A management plan for the Heritage Coast in the Flamborough
Head area defines a number of management zones as a means of ensuring that visitor use
and related development are appropriate to the character of different parts of the coast.
Landscape and wildlife conservation are given priority and other uses
(particularly recreation) are considered in the light of the zoning policy.
At the northern end of the Bay, the landward area adjoining Filey Brigg was designated a
Country Park in 1971 by the former East Riding County Council. Despite the
absence of a formal management plan for the park, the site provides a range of outdoor
recreational opportunities together with extensive caravan and car parking sites, and it is
popular with visitors. It affords particularly striking panoramic views over the Brigg
124
Chapter 5: Conservation
and Filey Bay and is also the start/finish point for two designated long-distance
footpaths: the Cleveland Way and the Wolds Way.
Although stretches of coastline outside the designated Heritage Coast have been
degraded by intensive post-war holiday development, the entire extent of Filey Bay from
Reighton northwards has been scheduled for planning protection under the tourism
area development policy incorporated within the Filey Local Plan. Its broad aim is to
conserve the natural amenities of the coast and enhance the area's tourism potential (see
section 4.3).
The six miles of sandy beaches which fringe the northern part of Filey Bay are an
important natural amenity, fundamental to the tourism industry. The beaches,
•
renowned for their safety and cleanliness, are amongst the finest on the Yorkshire
coast. Their quality can be judged from the fact that they were included in the Marine
Conservation Society's Good Beach Guide, given a 'Clean Beach Award' in 1988 by
the Tidy Britain Group and received the coveted Blue Flag designating their pollutionfree status under the EC scheme in 1990. Moreover, they emerged with a high rating in
the Consumer Association's own survey of British beaches undertaken in 1991, at a
time when the majority of English coastal resorts came in for severe criticisms on
grounds of health and safety.
5.4 Marine Protected Areas
The sub-littoral zone off Filey Bay does not enjoy the benefits of any protected status.
Little progress has been made nationally in the designation of Marine Protected Areas
(MPAs); only two MPAs have so far been designated, both off the west coast of
Britain. It is, however, clear that the waters off Flamborough Head merit serious
consideration mainly for their biological importance. A proposal in 1982 to establish a
voluntary marine conservation area around Flamborough Head lapsed, due mainly to
concerns about restrictions on fishing and recreational diving activities.
5.5 Summary and Conclusions
Filey Bay is an important area in terms of wildlife, landscape and amenity conservation.
Above the mean low water mark certain stretches of coastline are well protected under
SSSI, Heritage Coast and Country Park designations; other areas rely mainly on local
planning policies. The vulnerable littoral zones are afforded no statutory protection.
Yet these zones are rich in marine fauna, provide vital feeding grounds for the fish and
seabird populations and are essential components of the area's natural amenities.
125
Chapter 5: Conservation
Particular concerns arising from the threat of aggregate dredging in the Bay are for the
marine communities which form indispensable links in the natural food systems with
important ramifications for both wildlife and economic resources. More generally, the
threat is to the extent and quality of the beaches which are integral parts of the area's
important landscape amenities, again with potentially decisive repercussions for the local
economy.
Protection of the sublittoral zone from serious disturbance and damage is, in fact,
essential to the sustainability of the area's rich environmental and economic resources.
126
Chapter 6: Conclusions
6. CONCLUSIONS
This report is intended to bring together the many existing sources of information on
the physical, biological and economic environment of Filey Bay and to add to these data
specifically collected for the study. In doing so, this report provides the first overall
statement on Filey Bay and thus represents an important contribution to our knowledge of
this area. The report has, however, gone further than this. In collating the data
sources on the physical, biological and economic environment it has identified the
interactions between these various elements and thus provides more than a mere
compilation: it provides an holistic view of the ecology of Filey Bay.
The picture which emerges from such an holistic interpretation of the large data set
assembled here is one of complexity, as may perhaps be expected. More important ,
however, is the characterisation of Filey Bay as an extremely sensitive area, one which
has developed unique attributes of biological richness and physical stability in the face of
immense pressures, both natural and human which constantly threaten. Thus the contrast
between the relative stability of the coastline of Filey Bay and the chaotic erosional
activity of its southern neighbour — the Holderness coast, has been shown here to be
largely the result of a delicate balance between seabed sediment losses around
Flamborough head during northerly storms and the gain of equal amounts of sediment
carried north from Bridlington Bay by tidal currents and from cliff erosion within Filey
Bay itself.
Again the biological diversity and richness of the Bay is shown here to be the outcome of
the complex frontal systems which characterise the offshore marine environment here
and which cause nutrient accumulations, resulting in planktonic enrichment and
subsequent enhancement of the entire food web. It is on such a complex interaction
that the unique ornithological and fishing interests of the area depend, yet the
importance is not merely a parochial one since both birds and fish distributions over
much of the North Sea depend on Filey Bay as a vital nursery area.
The human activity of the area is no less dependent on a sensitive adjustment to a
difficult and complex environment. The fishing industry may of course be seen as part of
the food web already described but the tourist industry depends on the interaction
between both physical elements of the landscape such as the stability of Filey's beaches
and the biological elements — birds, fish and fishing.
127
Chapter 6: Conclusions
The vulnerability of such a complex of interaction has been stressed throughout the
report. Such vulnerability is not postulated on purely academ ic grounds. Past
experience has shown that interference, often of a minor nature, can result in gross
changes in the Bay. Extraction of sand from the beach was shown in the 1960's to
result in lowering of beach levels and accelerated cliff erosion with very serious effects
for both the fishing and the tourist industries. Trawling within the Bay was recognised
early in this century as having a deleterious effect on nursery fish stocks and a North
Eastern SFC prohibition has been in force since 1920 - one of the earliest forms of
voluntary conservation practiced in this country.
The many forms of environmental pressure now threatening Filey Bay must, in the face
of the sensitivity described above, be viewed with some alarm. These pressures may
be local in origin, for example, proposed marinas or the need to dispose of sewage
effluent, or they may represent national and international economic pressures - such as
hydrocarbon exploitation or aggregate dredging. In all cases the intrusion of foreign
structures or substances into this vulnerable marine system must result in overall
change reflected in both physical and biological components. The question which must
be addressed in all such cases is whether these changes in the Filey Bay environment
may be justified by the necessity for the development. It is the intention of this report not
only to demonstrate that such development will result in changes which will ramify
throughout the Filey Bay system, but also to provide a sound data base on which to
construct an informed judgement as to the ecological and economic cost-benefits of
such actions.
128
Chapter 7: References
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marinus (Raitt). I. The effect of food availability on activity and the role of ofaction in
food detection. J. Fish. Biol., 6, 565-576.
Winslade, P. R. (1974b). Behavioural studies on the lesser sandeel, Ammodytes
marinus (Raitt). II. The effect of light intensity on activity. J. Fish. Biol., 6, 577-586.
Winslade, P. R. (1974c). Behavioural studies on the lesser sandeel Ammodytes
marinus (Raitt). III. The effect of temperature on activity and the environmental control of
the annual cycle of activity. J. Fish. Biol., 6, 587-599.
Wood, E. (1988). Flamborough Head Sub-littoral Survey (832). Nature Conservancy
Council (English Nature).
131
Appendix A
Filey Bay Wav e Regime - Summery Report.
B. Denness, Bureau of Applied Sciences.
F i l e y B a y
Environmental Statement:
Appendices
Institute of Estuarine and Coastal Studies
Univers ity of Hull
December 1991
FILEY BAY WAVE REGIME
Summary Report
B y
BRUCE DENNESS
FILEY BAY WAVE REGIME
Summary Report
b y
Bruce Denness
Bureau of Applied Sciences
Zeta House
Daish Way
Dodnor Park
Newport
Isle of Wight
P030 5XJ
ENGLAND
1991
SUMMARY
The extraction by dredging of sand and gravel has been
proposed for Filey Bay. The neighbouring coastline is
sensitive to instability as may be the ecology of the
seabed and water column. Therefore it is appropriate to
explore the theoretical implications of the proposed works.
This report examines data relating to the characteristics
of neighbouring wave regimes and other physical information
with a view to providing input parameters for refraction
modelling, an essential prerequisite of the necessary
sediment transport analysis. It is concluded that the most
influencial waves come from the north and that a
significant deep-water wave height of 9 metres is the most
appropriate.
CONTENTS
Page
SUMMARY
1.
2.
INTRODUCTION
1.1.
Background
1.2.
Objectives
ANALYSIS
1
1
1
3
2.1.
Waves
3
2.1.1.
FLAMBOROUGH HEAD
3
2.1.2.
HOLDERNESS
4
2.1.3.
DOWSING
5
2.2.
Climate/Weather
6
2.2.1.
LONGTERM
6
2.2.2.
SHORTTERM
6
2.3.
Tidal Currents
6
2.4.
Residual Currents
7
2.5.
Bathymetry
7
2.6.
Sedimentology
7
2.6.1.
SOLID GEOLOGY
7
2.6.2.
BED FORM
8
2.6.3.
SEDIMENT DISTRIBUTION
8
2.6.4.
MEAN SAND SIZE
8
Page
3 . WAVE REFRACTION PARAMETERS
9
4.
CONCLUSIONS
10
5.
ACKNOWLEDGEMENTS
11
6.
REFERENCES
12
APPENDIX 1: FIGURES
13
APPENDIX 2: TABLES
41
FILEY BAY WAVE REGIME
Summary Report
1. INTRODUCTION
It is appropriate to consider the background to this
project from both an organisational and technical point of
view. This influences the presentational as well as
technical objectives.
1.1. Background
This study was carried out for the Institute of Coastal and
Estuarine Sedimentology (ICES) of the University of Hull as a
sub-contract to ICES's main contract from Filey Town
Council. The main contract is broadly to assess the likely
impact of proposed sand and gravel dredging in Filey Bay on
the stability of the seabed and neighbouring coasts and the
local biota. This sub-contract requires the derivation of
inpu t dat a on rel eva nt wa ve cha rac ter ist ic s for
mathematical wave refraction modelling matched against
existing seabed sedimentary information.
Wave forecasting has a long and distinguished international
history, led to a large degree by British oceanographers.
However, despite having a massive library of data on
worldwide wave regimes the national archives at the Marine
Information and Advisory Service (MIAS) of the Institute of
Oceanographic Sciences (I0S) hold only limited data
relevant to Filey Bay. Their paucity and short duration
requi re s pec ial i nte rpr etat ion bey ond t he s cope of
conventional analysis.
1.2. Objectives
It is required that this report leads to an assessment of
input data for wave refraction analysis across the proposed
site of marine dredging and neighbouring inshore waters.
However, the nearest archival information relates to
Flamborough Head, a much more exposed site, and is in any
case of only just over one year's duration. Fortunately
other data from a physically similar and possibly more
represe ntati ve site a t a more dis tant lo calit y off
Holderness are available (although of similarly short
duration), as are significantly longer term data from the
weather ship at Dowsing, some 90 kilometres southeast of
Filey Bay. This report seeks to optimise the route between
these disparate sets of data.
1
It cannot be ignored that the initial quotation for this
work was 60% higher than the figure currently available for
this stage of the project. As a consequence, bearing in
mind that there is no way of reducing the collection and
analysis of necessary data (otherwise the original
quotation would have been lower!), this report is
essentially of a rudimentary nature. It leads the reader
very abruptly through the supporting information and its
interpretation. Substantiation of a type suitable for indepth or legal presentation has necessarily been prepared
in order to derive the design criteria and conclusions
given here but is not included in this report.
The figures and tables referred to in the text are
presented in the appendices.
2
2. ANALYSIS
An extensive catalogue of information is summarised here
relating to various types of water movement relevant to the
sea condition in Filey Bay and its environs. Reference is
made to the graphical reduction of these nationally
archived data which are linked in an orderly if basic
fashion.
2.1. Waves
The main type of water movement likely to influence the
seabed stability in the wake of sand and gravel extraction
from Filey Bay is considered to be that generated by waves.
Therefore, it is necessary to establish the likely wave
regime across the extraction site and in neighbouring
waters for the more severe (indeed, most severe) seastate
conditions expected within a reasonable "lifetime" of the
site and proposed works, say 50 years. Here we briefly
examine means of aquiring the necessary design data from
suites of varying duration at neighbouring and distant
sites, all of which are located on Figure 1.
2 .1 .1 . FL AMB O RO U G H HE AD
The recording station off Flamborough Head provides
valuable information relating not only to significant wave
heights (the essential input to defraction modelling) but
also to wave periods and approach directions.
Unfortunately the archived records effectively lasted for
only 17 months (January 1985 - May 1986) so that they are
not necessarily representative of the longterm condition.
However, let us look at this limited resource.
Figure 2, based on Table 1 (rearranged from Table 4a of
Clayson and Ewing, 1990), describes the directional
variation of waves of different significant height passing
a Datawell WAVEC buoy off Flamborough Head:
it is a
compendium of all data during the 17-month deployment.
Figures 3-6, based on Tables 2-5 (rearranged from Tables
4b-e of Clayson and Ewing, 1990), repeat this exercise for
the winter, spring, summer, and autumn seasonal data
respectively. In this case winter is defined as Dec - Feb,
spring as Mar - May, summer as Jun - Aug and autumn as
Sep - Nov.
These figures show that the main deep-water wave approach
direction throughout the year is from the northern 450
sector for all significant wave heights with secondary
approach directions from the southeast 450 sector for low
waves and from the northeast and east 450 sectors for higher
waves. The data suggest that the higher waves come
overwhelmingly from the north and it is these that would be
3
responsible for the great majority of any seabed sediment
transport when refracted into Filey Bay. The lower waves
from the southeast should theoretically result in the
return of fines to the north in winter to give a slight
gradation of sediment increasing in coarseness to the south
(see Sections 2.6.3 and 2.6.4).
Figure 7 merely rearranges the information in Figure 2 into
t h e mo r e fa m il i ar ( bu t l es s ea s il y i nt e rp r et e d
quantitatively) presentation of a rose diagram.
Figure 8, based on Table 6 (from Table 5a of Clayson and
Ewing, 1990), describes the directional variation of all
waves of different period passing the buoy during its 17month deployment. Figures 9-12, based on Tables 7-10 (from
Tables 5b-e of Clayson and Ewing, 1990), portray the
seasonal data for different wave periods as previously
above for wave heights.
These figures confirm that the main deep-water wave
approach direction for all significant waves is from the
north with secondary approach directions form the southeast
for low-period (high frequency) waves, associated with
lower wave heights, and from the northeast and east for
l o ng er pe ri od (h ig he r) w av es . A s d ee p- wa te r w a ve s
generally exhibit a close relationship between wave height
and period these figures indicate that the whole of the
Flamborough data set are internally sound and representative of the duration of their record.
Figure 13 merely rearranges the information in Figure 8
into the more familiar rose diagram. Figure 14 compares
the maximum and mean significant wave heights at
Flamborough and Dowsing for the whole of the year 1985 on a
m o nt hl y b as is , e xc ep t f or t h os e Do ws i ng r ec o rd s
indicating missing data. It can be seen that the two sites
generally experience similar sea-state conditions, although
the Dowsing data is non-directional, with Flamborough waves
averaging 10% greater height in general and 61% for one
month. It is interesting that, in general terms for this
particular year the winter season, normally associated with
generally heavier seas, is Nov - Jan for both sites (unlike
the Dec - Feb assumed by Clayson and Ewing, 1990): this is
further explored in Section 2.1.3.
2.1.2.
HOLDERNESS
Bacon a nd Car ter ( 1988) repo rted t he re cord of tw o
Waverider buoys, one nearer shore than the other from March
1986 to March 1987 (13 months inclusive). Figure 15
compares the significant wave heights at the two sites with
those off Flamborough Head on a daily basis for the two
months early - March to early - May, 1986, during the only
4
period in which both sites were operational at the same
time. The similarity in both scale and contemporaneity is
most encouraging for the entrapolation of more distant
longer term more southerly records to Flamborough and
beyond into Filey Bay, the reason for performing this
comparison.
2.1.2.
DOWSING
The Dowsing Light Vessel has deployed a Shipborne Wave
Recorder from 1970 to the present with a few breaks in
recording, particularly during 1971-1975. Bacon (1989)
reported on the period up to 1985. Figure 16 is based on
the data in Table 11 (itself taken from Table 8 of Bacon,
1989, and completed with averaged data for those months
with missing data): the broken contours exphasize the
uncertainty arising from this procedure. Both the mean
monthly significant wave height for the whole period and
that for most individual years suggest that the "winter"
period, generally associated with the highest seas (the
condition most relevant to this study), is Nov - Jan rather
that the Dec - Feb favoured by Clayson and Ewing (1990) for
Flamborough. However, we have already seen (Section 2.1.1)
that this may have been a misleading interpretation on
their part, perhaps borne from a review of British climatic
data which does exhibit a "winter" of Dec - Feb for several
w e a t he r -r e l at e d p a r am e te r s . N o rt h Se a w av e da t a ,
especially that from a northerly direction as prevails in
deep water off the northeast coast, is strongly influenced
by the weathe r pat tern in th e Nort h Atl antic whic h
experiences a different seasonal variation than that over
Britain:
hence the difference between wave and local
climatic seasons.
Figure 17 is based on the data in Table 12, which is taken
from Table 9 of Bacon (1989), duly enhanced as above. This
shows essentially the same seasonal pattern for maximum
significant wave heights as does Figure 16 for their means
and further emphasises the advisability of utilizing wave
data for the Nov - Jan period rather than Dec - Feb for all
northeast coast sites in relation to assessing seabed
transport characteristics of Filey Bay.
The mean and maximum winter (Nov - Jan) significant wave
height records, subjected to a moving average smoothing,
are given in Figure 18, with periods of uncertainty (most
of them) indicated by a broken line. The figure also
portrays the variation of h5(50), the height of the maximum
significant wave with a return period of 50 years ( a
rep res en tat iv e s ite op era ti on inf lu enc e l if eti me )
interpreted for different whole years of data using a
Fisher-Tippett Type 1 model fitted to monthly maxima.
These interpretations range from 7.43 m in 1975 - 1976 to
5
9.26 m in 1979 for a probability approaching 0.999999, a
variation of 25%. This has significant implications for
interpreting records both near to and further from Filey
Bay. For tunat ely, as wou ld be expec ted, t here is a
tentative correlation between the forecast h5(50) and the
general trends of observed winter wave heights.
2.2. Climate/Weather
It is appropriate at this stage to explore relationships
between the variation of both observed and forecast wave
height data and real and modelled climate and weather time
series. This could facilitate a more logical forecast of
h5(50) than might otherwise arise from the analysis of the
relatively shortterm nearest record (off Flamborough Head)
to Filey Bay.
2 .2 .1 . L ONGTE RM
A correlation has already been shown between the forecast
h5(50) at various times between 1970 and 1985 and observed
winter significant wave heights at Dowsing (Figure 18).
This is further seen in Figure 19 in the general relation
between the variation of the significant winter wave height
at Dowsing and a model of the variation of the natural
component of global temperature change from Denness (1987a,
1990, etc), again as would be expected. As the climate
model is time-based and deterministic it can be used to
assess the likely variation of future significant wave
heights to check on the advisability or otherwise of using a
standard Fisher - Tippett interpretation alone. This is
incorporated in the overall assessment in Section 3.
2 .2 .2 . S HOR TT ER M
Figure 20 takes the consideration of shortterm climate
(weather) a little further by comparing averaged 24-hour
wind speed at Dowsing, with no account taken of direction,
with the variation of the maximum significant wave height
off Flamborough Head for January, 1986, a month for which
the weather data is coincidentally to hand. This month is
common to both possible "winter" seasons and shows a
tenuous correlation of winds (weather) with wave height:
This shortterm climate analysis complements the earlier
long-term review to some degree.
2.3. Tidal Currents
The maximum tidal streams at mean spring tides are shown in
Figure 2 1. Th is sug gests that the ma ximum spee d of
movement (essentially north or south) of the water column
6
Filey Bay on an approximately semi-diurnal basis is about
an order of magnitude less than likely major wave-induced
movement and is unlikely to cause significant permanent
uni-directional transport of clas tic sedim ent in a
superimposed dredging regime even under the influence of
simultaneous major wave action.
2.4. Residual Currents
The general residual current pattern off the northeast
coast, including Filey Bay is shown in Figure 22, taken
from Denness (1987b). The residual current integrates to
the offset of movement of the water column, or various
parts of it, after a complete tidal cycle and is therefore
no more significant as a sediment transport agent than the
tides themsel ves. How ever, in Filey Bay t he winte r
residual currents are to the south so that fines (smaller
than clastic particles) would be winnowed out by tidal
action, even without wave activity, and transported south
to lead to the overall coarsening of sediment during
dredging.
2.5.
Bathymetry
The general variation of the depth of
and its immediate environs relevant
refraction diagrams is shown in Figure
the local large scale Admiralty Chart.
be sufficiently accurate to match the
input wave characteristics.
2.6.
water in Filey Bay
to preparing wave
23, extracted from
This is thought to
sensitivity of the
Sedimentology
In the present context a review of sedimentological factors
benefits from an understanding of the solid geology beneath
the superficial deposits on the seabed, the local and
neighbouring physical bed form, generally observed sediment
distribution and the local variation of sizes of sand
particles within the sediment.
2.6.1.
S O L I D GE OL O G Y
The submarine solid geology under Filey Bay comprises a
suite of Jurassic rocks. The current solid geology map
published by the British Geological Survey, enlarged here
in Figure 24, shows undifferentiated Jurassic rocks
throughout the bay and its surrounding area: this provides
no indication of the likely impact of dredging.
7
2.6.2.
BED FORM
The bed form offshore from Filey Bay is shown in Figure 25
which has been enlarged from the bedform map published by
the British Geological Survey. The figure shows rock or
gravel at or near seabed surface, accompanied by streaks,
elongated patches, or ribbons of sand to within about 6
kilometres of the shore, landward of which the bedform is
undifferentiated. Sand streaks, ribbons, ripples or waves
are indicative of natural transport of clastic sediment,
suggesting that the movement of some superficial materials
is already underway prior to dredging.
2.6. 3. S ED I MEN T D I S TR I BU T ION
Figure 26, from the sediment map published by the British
Geological Survey, portrays the distribution of sediment
types in and adjacent to Filey Bay. It shows more or less
gravelly sand throughout most of the area grading to a
coarser deposit of sandy gravel centred on part of the area
of propos ed dred ging. A n interr upted b and of mu ddy
m a te ri al s i s fo un d be tw ee n ap pr ox im at el y 3 an d 12
kilometres offshore in the north of Filey Bay, approaching
closer to shore to the south but missing from the centre of
the bay. As there is no indication whether this is due to a
variable source or winnowing this
volunteers little
information in itself relating to sediment transport.
2.6.4.
MEA N SA ND S I ZE
The mean grain size of the sand fraction of seabed sediment
off the Filey coast is shown in terms of phi values in
Figure 27 which is enlarged from the phi map published by
the British Geological Survey. This suggests that the sand
fraction coarsens offshore. This does not necessarily
imply that the whole sediment experiences a similar trend
but may suggest that wave influence is significant in
winnowing perpendicular to the coast.
8
3. WAVE REFRACTION PARAMETERS
Using all data from the 1985-1986 wave record off
Flamborough Head, Clayson and Ewing (1990) show the
estimated local deep-water hs(50) to be 8.80 metres with a
probability of 0.99999. Though no direction is attributed to
this it is clearly likely to arrive from the north (Figs 26). Comparable estimates for the offshore station at
Holderness for 1986-87 and for the 1970-85 record at
Dowsing are 5.52 metres and 7.99 metres respectively.
It has been shown here that it is possible to extrapolate
from the well-separated sites of Flamborough, Holderness
and Dowsing. It has also been shown that the winter wave
season at these sites tends to be during Nov-Jan instead of
the more commonly asserted Dec-Feb: this would tend to
increase h5(50) slightly.
We have also seen that at Dowsing, which boasts the longest
term record, estimates of h5(50) vary, according to Bacon
(1989), depending on the part of the record that is
examined but that the estimates (and the seastate on which
it is based) relate to the natural climate model (and the
real climate record) of Denness (1987a, 1990, etc).
In summary, we have conflicting views on the interpretation of
a representative significant wave height to put into a wave
refraction diagram. This is further aggravated by the fact
that the commonly used Weibull interpretation gives
between 10 and 22% lower estimates of h5(50) than the
Fisher-Tippett Type 1 used here.
The description of the rationale leading to the optimum
selection, incorporating all the above considerations and
more, is long and tedious. However, it leads to the
selection of h5(50) = 9.00 metres from a northerly direction as
the worst condition thought likely to have the greatest
impact on the coast and inshore biota. It would also be
sensible to prepare refraction diagrams with h5(50) = 7.00
m from the northeast, h5(50) = 6.00 m from the east and hs(50) =
5.00 from the southeast to check the possible impact of
waves from less influencial directions. After these
diagrams have been prepared estimates could be made of the
likely influence of lesser seastates in the shorter term.
9
4. CONCLUSIONS
As there are no archived wave characteristics data for
Filey Bay it is necessary to extrapolate from records
remote from the site and to interpret indirect information
relating to the local and neighbouring seabed in order to
assess appropriate significant waves for the preparation of
wave refraction diagrams and subsequent sediment transport
analyses. Large discrepancies are present between
published interpretations of these data, depending largely
on the duration of the records and the method of
interpretation. Nevertheless experience dictates that a
sensible path can be chosen through the conflicting time
series and interpretation techniques. This results in the
selection the design waves in Section 3 with particular
emphasis on the worst case of h5(50) 9.00 metres from the
north.
10
5. ACKNOWLEDGEMENTS
The writer is grateful to John Pethick of ICES for
providing a clear brief and recognising the constraints
imposed by the project budget. Thanks are also due to the
Sons of Neptune of Scarborough for permission to use
residual current information from a report the writer
prepared for them in 1986-87.
11
6 . R EF E RE N C ES
BACON, S. (1989): Waves recorded at Dowsing Light Vessel
1970-1985. Rep No. 262, Institute of Oceanographic
Sciences, 6 Opp.
BACON, S and D.J.T. CARTER (1988): Waves and wave spectra
recorded at two sites off Holderness 1986-1987.
Rep. No. 260, Institute of Oceanographic Sciences,
88 pp.
CLAYSON, C.H. and J.A. EWING (1990): Directional wave data
recorded off Flamborough Head. Rep. No. 273,
Institute of Oceanographic Sciences, 45 pp.
DENNESS, B. (1987a): Sea level modelling: the past and
the future. Prog. Oceanog., 18, 41-59.
DENNESS, B. (1987b): Sewage Disposal to the Sea. Sons of
Neptune, Scarborough, UK, 68 pp.
DENNESS, B. (1990): Determining natural and manmade climate
change: historical review and implications for the
1990's and beyond IN Greenhouse Effect, Sea Level and
Drought (eds. R. Paepe, R. Fairbridge and S.
Jelgersma). Kluwer Academic Publishers, Dordrecht,
41-74.
12
Appendix 1: Figures
73
Figure 1: Site location map
14
Figure 2: Direction of all significant
waves off Flamborough
15
Figure 3: Direction of significant
winter waves off Flamborough
16
Figure 4: Direction of significant
spring waves off Flamborough
17
Figure 5: Direction of significant
summer waves off Flamborough
18
Figure 6: Direction of significant
autumn waves off Flamborough
19
Figure 7: Flamborough wave
height rose
Figure 8: Direction of all wave
periods off Flamborough
21
Figure 9: Direction of winter wave
periods off Flamborough
22
Figure 10: Direction of spring wave
periods off Flamborough
23
Figure 11: Direction of summer wave
periods off Flamborough
24
Figure 12: Direction of autumn wave
periods off Flamborough
25
Figure 13: Flamborough wave
period rose
Figure 14: Significant wave heights at
Flamborough and Dowsing during 1985
27
Figure 15: Comparison of significant
wave heights off Flamborough
and Holderness
28
Figure 16: Monthly mean significant
wave height at Dowsing (1970 - 1985)
29
Figure 17: Monthly maximum significant
wave height at Dowsing (1970 - 1985)
30
Figure 18: Mean and maximum
significant winter wave heights at
Dowsing versus 50-year forecast max.
31
Figure 19: Global temperature
versus significant wave height
Figure 20: Wind speed and significant.
wave height at Dowsing (Jan 1986)
Figure 21: Maximum tidal streams in
Filey Bay at mean spring tides
34
Figure 22: Residual winter currents
off Filey Bay
35
Figure 23: Bathymetry in and
around Filey Bay
36
Figure 24: Solid geology in and
around Filey Bay
37
Figure 25: Bed form in and
around Filey Bay
38
Figure 26: Seabed sediments in
and around Filey Bay
( F o lk . R. L. 1 9 7 4: P e t r o l og y o f s e d i m e nt a r y ro ck s .
Hemphill Pub. Co, Austin. Texas, 182pp.)
39
Figure 27: Mean grain size of sand
fraction in and around Filey Bay
(phi units)
40
Appendix 2: Tables
41
TABLE 1:
Direction of all significant wave heights off Flamborough
Bearing
H s(m)
0
45
90
135
0-0.5
68.6
10.2
20.7
24.1
5.6
3.7
1.0
2.6
136.5
0.5-1.0
159.1
18.8
25.1
71.9
24.1
9.9
17.8
24.6
351.5
1.0-1.5
90.3
20.8
20.8
49.9
19.2
2.1
6.6
3.5
223.2
1.5-2.0
66.6
21.7
10.2
18.7
4.2
-
4.4
6.3
132.1
2.0-2.5
32.8
13.7
4.7
6.6
1.5
0.3
0.3
2.0
61.9
2.5-3.0
17.1
12.1
4.4
4.1
0.5
-
0.2
1.6
40.0
3.0-3.5
9.3
3.7
3.0
2.6
-
-
-
2.1
20.7
3.5-4.0
7.3
2.9
0.2
0.2
-
-
-
0.8
11.4
4.0-4.5
6.1
2.0
0.5
-
-
-
-
-
8.5
4.5-5.0
4.8
0.3
-
-
-
-
-
0.2
5.3
5.0-5.5
4.7
-
-
-
-
-
-
-
4.7
5.5-6.0
3.2
0.1
-
-
-
-
-
-
-
-
-
-
-
-
-
-
3.2
0.1
16.0
30.3
6.0-6.5
Totals
470.0
106.2
89.6
178.1
180
55.1
42
225
270
315
Totals
53.7 1000
TABLE 2:
Direction of significant winter wave height5 off Flamborough
Bearing
Hs(m)
0
45
90
0-0.5
39.7
135
180
225
21.6
12.7
-
270
-
9.1
315
-
Totals
83.1
8.1
203.9
14.6
5.8
11.3
7.6
96.5
55.1
4.8
0.5-1.0
233.1
26.6
7.3
48.4
6.5
5.1
92.4
34.2
12.4
1.0-1.5
8.1
14.8
201.9
56.1
25.0
14.8
65.9
17.1
-
1.5-2.0
0.8
6.9
103.3
38.9
23.5
9.9
17.9
4.1
0.8
2.0-2.5
80.8
15.3
13.1
16.5
-
2.9
29.9
2.2
0.8
2.5-3.0
9.8
2.9
10.5
-
-
14.3
14.3
-
2.2
3.0-3.5
9.8
0.8
-
-
-
19.0
6.9
-
1.5
3.5-4.0
1.8
-
16.5
3.3
-
-
11.4
-
-
4.0-4.5
-
-
-
-
-
8.8
8.1
-
0.8
4.5-5.0
-
-
-
-
-
4.4
4.4
-
-
5.0-5.5
-
-
-
-
-
5.1
-
-
-
5.5-6.0
5.1
-
-
-
-
-
-
-
-
6.0-6.5
Totals
413.5
159.1
67.0
195.8
43
72.6
12.1
36.4
42.3
1000
TABLE 5:
Direction of significant autumn wave heights off Flamborough
Bearing
0
45
90
135
180
225
270
315
Totals
Hs(m)
-
-
-
0-0.5
37.5
5.4
0.5-1.0
196.1
12.5
1.0-1.5
96.7
19.7
11.6
9.0
61.8
51.0
45.7
1.5-2.0
98.5
10.7
12.5
14.3
2.0-2.5
51.9
27.8
2.7
-
-
2.5-3.0
13.4
3.6
-
3.0-3.5
4.5
23.3
-
0.9
-
9.0
-
3.5-4.0
6.3
-
4.0-4.5
7.2
-
0.9
-
4.5-5.0
9.0
-
5.0-5.5
13.4
5.5-6.0
6.0-6.5
5.4
-
Totals
,
540.0
-
20.6
9.8
17.0
18.8
8.1
0.9
2.7
-
2.7
36.7
19.7
54.6
374.2
247.1
-
144.1
-
-
-
-
-
83.3
40.3
-
-
-
-
-
-
-
0.9
-
14.3
7.2
-
-
-
-
-
7.2
-
-
-
-
-
-
9.0
-
-
-
-
-
-
-
13.4
-
-
-
-
-
-
-
5.4
-
98.5
92.2 131.7
47.5
46
10.7
19.7
60.0
1000
T AB L E 7:
Direction of 5ignificant winter wave periods off Flamborough
Bearing
Period
(Sec)
0
45
90
135
180
225
270
315
Totals
-
-
-
-
-
-
-
-
-
2.0-2.5
-
-
-
-
-
-
-
-
-
2.5-3.0
-
-
-
1.8
2.6
3.0-3.5
-
-
-
12.7
3.5-4.0
-
-
-
4.0-4.5
-
1.8
-
4.5-5.0
-
1.8
1
.5-2.0
-
-
-
-
4.3
13.8
3.7
3.3
-
33.3
3.6
6.9
5.1
8.3
-
23.9
14.2
8.4
2.6
14.3
0.8
42.1
0.8
9.8
15.1
-
5.9
0.3
34.1
11.6
33.6
14.3
0.8
3.7
10.3
87.4
5.0-5.5
13.0
5.5-6.0
6.1
4.3
5.8
21.9
2.9
-
0.8
5.1
47.2
6.0-6.5
9.5
10.6
4.3
35.6
6.6
-
-
6.9
73.6
6.5-7.0
12.8
14.8
9.8
21.6
2.2
-
-
8.8
70.1
7.0-7.5
15.3
27.2
8.4
13.9
-
-
-
3.7
68.7
7.5-8.0
24.4
48.8
17.9
24.1
-
-
-
3.7
119.1
8-9
46.3
31.9
7.6
2.9
-
-
-
0.8
46.3
9-10
67.2
11.6
0.8
-
-
-
-
1.3
81.0
10-11
111.5
6.1
-
-
-
-
-
-
117.7
11-12
80.3
-
-
-
-
-
-
-
80.3
12-13
13-15
20.0
7.2
-
-
-
-
-
_
-
-
-
-
-
-
-
-
Totals
413.6
158.9
67.0
195.7
72.8
48
12.2
36.3
42.4
20.0
7.2
1000
TABLE 8:
Direction of significant spring wave periods off Flamborough
Bearing
Period
(Sec;
0
-
45
90
135
-
1.5-2.0
180
225
270
315
Totals
-
-
-
-
-
0.6
-
-
-
0.6
0.6
2.0-2.5
-
-
-
0.6
-
2.5-3.0
-
-
-
-
1.1
1.8
-
0.6
3.5
3.0-3.5
0.6
-
3.5
13.8
4.6
5.3
3.6
0.6
31.9
3.5-4.0
0.6
C.6
6.4
28.9
7.6
0.6
8.6
2.9
56.1
4.0-4.5
4.0
2.4
20.5
46.6
5.8
0.6
4.6
6.4
90.8
4.5-5.0
5.2
1.7
17.7
40.9
5.7
-
2.3
11.0
84.5
5.0-5.5
13.5
9.9
25.1
34.5
2.8
1.1
2.3
11.0
100.4
5.5-6.0
18.1
12.9
9.3
20.3
0.6
-
-
4.1
65.3
6.0-5.5
48.1
36.0
22.8
32.1
0.6
-
-
6.4
145.9
6.5-7.0
36.0
18.6
11.5
2.3
-
-
-
1.8
70.3
7.0-7.5
26.5
21.4
5.2
1.1
-
-
-
3.6
57.8
7.5-8.0
26.7
23.4
-
1.8
-
-
-
3.6
55.4
8-9
47.9
13.8
-
0.6
-
-
-
1.8
64.2
9-10
41.6
10.3
-
-
-
-
-
-
52.1
10-11
52.2
0.6
-
-
-
-
-
-
52.8
11-12
51.0
-
-
-
-
0.6
-
-
51.6
12-13
15.6
-
-
-
-
-
-
-
15.6
13-15
0.6
-
-
-
-
-
-
-
0.6
Totals
388.2
151.6
122.6
223.5
28.8
10.0
21.4
49
53.8
1000
TABLE 9:
Direction of significant summer wave periods off Flamborough
Bearing
Period
(Sec)
0
45
90
135
180
225
270
315
-
-
-
-
-
-
_
-
2.0-2.5
-
-
-
-
2.0
3.1
2.0
2.5-3.0
-
-
-
3.1
6.1
15.4
3.1
3.0-3.5
-
-
1.0
4.1
7.2
9.2
3.5-4.0
-
1.0
1.0
12.3
15.4
4.1
4.0-4.5
6.1
1.0
17.4
31.8
19.5
4.5-5.0
13.3
3.1
13.3
27.7
5.0-5.5
20.5
5.1
21.5
Totals
_
1 .5-2.0
7.2
-
27.7
12.3
3.1
36.9
19.5
13.3
66.6
-
7.2
13.3
96.3
12.3
-
-
15.4
85.0
35.9
8.2
-
-
6.1
97.3
12.3
-
-
-
2.0
47.1
18.4
1.0
-
-
6.1
84.0
5.5-6.0
24.6
1.0
7.2
6.0-6.5
42.0
1.0
15.4
6.5-7.0
32.8
-
-
11.3
-
-
-
-
44.1
7 .0-7.5
74.8
2.0
-
5.1
-
-
-
-
82.0
7.5-8.0
80.9
1.0
-
-
-
-
-
-
_
-
-
-
109.6
,
82.0
109.6
-
-
-
9-10
92.2
-
-
-
-
-
-
-
92.2
10-11
41.0
-
-
-
-
-
-
-
41.0
1.0
-
-
-
-
-
-
-
1.0
-
-
8-9
1 1 -12
12-13
13-15
Totals
-
-
-
-
-
-
-
-
-
-
-
-
-
-
538.8
15.2
76.8
162.0
71.7
50
31.8
44.1
59.3
1000
TABLE 10:
Direction of significant autumn wave periods off Flamborough
Bearing
Period
(Sec)
0
45
90
135
180
225
270
315
Totals
-
-
-
-
-
-
-
-
-
2.0-2.5
-
-
-
-
-
-
-
-
-
2.5-3.0
-
-
-
-
1.8
-
2.7
-
4.5
3.0-3.5
-
-
-
1.8
2.7
4.5
6.3
-
15.2
3.5-4.0
-
-
-
14.3
4.5
6.3
8.1
9.0
42.1
4.0-4.5
-
0.9
0.9
17.9
10.7
-
2.7
14.3
47.4
4.5-5.0
1.8
0.9
0.9
23.3
9.8
-
-
16.1
52.8
5.0-5.5
1.8
7.2
4.5
26.9
13.4
-
-
9.0
62.7
5.5-6.0
9.0
8.1
2.7
19.7
3.6
-
-
3.6
46.6
6.0-6.5
21.5
21.5
36.7
19.7
0.9
-
-
6.3
106.5
6.5-7.0
21.5
4.5
20.6
5.4
-
-
-
0.9
52.8
7.0-7.5
25.1
17.0
12.5
2.7
-
-
-
0.9
58.2
7.5-8.0
36.7
21.5
1.8
-
-
-
-
-
60.0
99.4
15.2
6.3
-
-
-
-
-
120.9
9-10
119.1
1.8
5.4
-
-
-
-
-
126.2
10-11
82.4
-
-
-
-
-
-
-
82.4
11-12
49.2
-
-
-
-
-
-
-
49.2
12-13
51.9
-
-
-
-
-
-
-
51.9
13-15
20.6
-
-
-
-
-
-
-
20.6
1.5-2.0
8-9
Totals
540.0
98.6
92.3
131.7
51
47.4
10.8
19.8
60.1
1000
TABLE 11: Monthly mean H5 at Dowsing (1970-1985)
Month
Year
1
/970
(1.67)
1.14
1971
2
3
(1.43) (1.42) (1.23)
1.24
1.37
(1.67)
1973
(1.67)
1974
(1.67) (1.43) (1.42)
1975
(1.67) (1.43) (1.42)
1977
1978
1979
1.20
(1.43) (1.42) (1.23)
1.10*
6
0.80
1.51
1.33
1.09**(1.23) (1.05) (0.86) 1.16**
1.74
1.60
(1.67)
1984
2.06
1.82
1985
Average
0.89
1.09
10
1.50
(1.23) (1.05) (0.86) (0.89) (0.95) (1.20) (1.37)
1.52
.22
1.22
1.41
1.92
2
1.63
11
1.58
12
1.69
1.54
1.14
0.92
0.62
1.44
0.74
0.81
1.32
1.51
1.43
1.33
1.35
1-29
1.64
1.43
1.27
2.1 9
1.68
1.49
1.04
1 . 0 4
1.08
1.11
1 . 4 7
1.18
1.65
2.23
1.24*
1.23
1.08
0.80
0.95
0.81
1.02
1.10
1.17
1.06
1.48
1.57
1.94
2.00
1.86
2.19
1.21
2.12
1.13
1.14** 1.02
0.85
0.85
0.76
0.85
0.85
1.22
1.43
1.48
1.30** 0.85
0.83
0.50
0.76
1.27
1.52
1.25
1.55
1.04
1.46
1.36
0.79
1.20
0.89
1.11**(1.42) (1.23) (1.05) 0.57** 0.72
0.60
1.00
1.40
0.93
1.32
1.01
1.58
1.95
1.29
1.43
1.13**1.19
1983
9
(1.05) (0.86) (0.89) (0.95) (1.20) (1.37) (1.65) (1.69)
1.29
1.81
8
(1.05) (0.86) (0.89) (0.95) (1.20) (1.37) (1.65) (1.69)
2.21
1982
1.03
1.84
1.98
1.62
1981
7
(1.23) (1.05) (0.86) (0.89) (0.95) (1.20) (1.37) (1.65) (1.69)
1980
(1.43) (1.42)
1.11 *'(0.89)
(0.95) (1.20) (1.37) (1.65) (1.69)
(1.67) (1.43) (1.42) (1.23) (1.05) (0.86) (0.89) (0.95) (1.20) (1.37) (1.65) (1.69)
= 10-20% missing
data
**
. >20% missing data
()
= Average
_
5
(1.43) (1.42) (1.23) (1.05) (0.86) (0.89) (0.95) (1.20) (1.37) (1.65) (1.69)
1972
1976
4
= 1970-1985 maximum
52
TABLE 12: Monthly maximum H5 at Dowsing (1970-1985)
Year
Month
1
1970
2
(4.29) (3.79)
1971
2.48
4
(3.94) (3.60)
7
8
9
1.78
3.94
3.58
3.39
10
4.77
11
4.09
12
4.83
(2.95) (2.32) (2.65) (3.07)
(3.21) (3.84)
(4.04) (4.46)
(3.94) (3.60) (2.95) (2.32) (2.65) (3.07)
(3.21) (3.84)
(4.04) (4.46)
1973
(4.29) (3.79)
(2.94) (3.60) (2.95) (2.32) (2.65) (3.07)
(3.21) (3.84)
(4.04) (4.46)
1974
(4.29) (3.79)
(3.94) (2.60) (2.95) (2.32) (2.65) (3.07)
(3.21) (3.84)
(4.04) (4.46)
1975
(4.29) (3.79)
(2.94) (3.60) (2.95) (2.32) (2.65) (3.07)
(3.21) (3.84
2.96
3.67
2.52
4.45
2.85
1977
1978
5.69
3.71
1979
4.93
6
.29
6.05
1980
1981
5.01
3.59
4.73
4.26
1952
1953
2.75
2 .42* *(3 .60
3.33
3.65
4.12** 2.36
3.25 '
(4.29)
(3.79) (3.94)
4.93
19E5
Average
3.57
5.27
1.77
(2.95) (2.32)
2.47
3 59*
7
2. 4
4.70
3.61
5 . 0
4
3.53
2.52
2.96
.
w
1984
*
4.16
3.54
2.51*
6
(4.29) (3.79)
4.13
3.53
5
1972
1976
4.53
3
2.45
3.09
3.10 •. 2.70
5.23
3.94
2.97
2.76
4.03
3.18
4.13
4.43
4.12
3.09
3.91
4.91 5 . 6 1
2.53
3.11
2.92
1.59
2.52
2.81
3.67
2.35
5.04
2.62
2.60
3.16
2.68
5.33
5.53
4.67
3.20 2.67 * * (2.65)
(3.07)
(3.21) (3.84)
3.25
3.04 2 . 9 5
3.27 w*
2.90
1.96
2.05
2.70
2.94
1.39
2.51
3.90
2.63
2.91
2.14
3.68
3.03
2.90
3.52 2.10 * * (3.94)
(3.60) (2.95) 0.94 w* 2.37
3.78
(4.29) (3.79) (3.94) (3.60) (3.95) (2.32) (2.65) (3.07)
= 10-20% missing data
**
= >20% missing data
()
= Average
_
= 1970-1985 maximum
53
•
(4.04) (4.46)
3.71
3.48
3.20
3.10
4.58
4.61
3.90
3.21
3.30
2.74
2.52
(3.21) (3.84)
3.60
4.32
(4.04) (4.46)
Appendix B
F iley Bay P roject . Report 91/2.
J. Hardisty, Unico GeoSystems Ltd.
Filey Bay Project
Report 91/2
J.Hardisty
August 1991
F ile y Ba y P roj e c t : R epo rt 91/ 2
SUMMARY
1.
2.
3.
An introduction to the assessment of seabed and nearshore sediment transport in
Filey Bay and within the context of dredging proposals is given. In particular the
threshold grain condition, transport path and wave regime criteria which are
utilised to assess dredging proposals are discussed.
The shoaling wave heights, peak oscillatory currents and resulting threshold
grain sizes are modelled for the fifty year significant wave heights from north,
north-east, east and south-easterly directions (Cases I to IV respectively). The
results suggest that all existing nearshore sediments will be mobilised by each of
these wave regimes except, perhaps, for the coarser material lying in deeper
water to the north of the Bay in Case IV.
The orthogonal sediment transport rates under Cases I to IV are modelled. The
results suggest that beach draw down and onshore sediment transport from
beyond the breakers will lead to net erosion and transport towards the breakers
of between 1 and 4 m3/m/day of sediment
4.
The longshore sediment transport rates around the Bay under cases Ito IV are
modelled. The results suggest that points of convergence are developed within
the Bay in Cases II to IV, and longshore rates are sufficiently large to
redistribute material brought into the surf zone from offshore. The Bay is thus
closed under these conditions, and only under the fifty year northerly waves is
there net transport, and this is towards the south.
5.
The change in the nearshore wave regime which results from the removal of 2m
of seabed material between 1,000m and 2,000m offshore for a southeasterly
orthogonal (Case III) is modelled. The results suggest that there is an increase of
about 2% in nearshore wave heights under such conditions.
6.
The amplitude of broadband, resonant edge waves in the Bay is modelled. The
results suggest that significant wave energy will be present under storm
conditions as edge waves and it is suggested that further work on this particular
aspect of the problem may attract research council funding.
The Remainder of this report (Appendix B) contains numerous mathematical formulae
and is of a highly technical nature. It can be examined by application to Filey
Against Dredging. Email [email protected]
Appendix C Deals with the specifications for Special Sites of Scientific Interest in the
area of Filey Brigg and Flamborough Head. More comprehensive and up to date
details of such sites, together with maps can currently be found at:
http://www.english-nature.org.uk/special/sssi/