Berrow Dunes
Local Nature
Reserve
For your safety
At low tide it is not advisable to walk towards the sea. The mudflats are soft and
the tide comes in quickly with strong currents. Please observe the safety signs
on the beach.
Visitors are asked to follow the Country Code:
• Guard against all risk of fire
• Keep your dogs under close control
• Clear up dog mess
• Keep to the paths
• Take your litter home
• Do not pick wild flowers
• Horse riders, please keep to the bridleways
Introduction
Berrow Dunes Local Nature Reserve (LNR)
is part of the much larger Berrow Dunes
Site of Special Scientific Interest (SSSI). It
is also next to a National Nature Reserve,
Bridgwater Bay, which is a wetland
habitat of international importance.
Sand dunes are relatively rare in the UK
and growing rarer across Europe. They
occur when sand, dried out at low tide, is
blown inland by onshore winds and
forms mounds that are anchored by
grasses growing on top of them.
The reserve at Berrow is managed by
Sedgemoor District Council, Natural
England and Berrow Conservation Group,
to maintain and enhance its important
habitats and make them attractive for
visitors. It is also used as an educational
resource by schools and colleges.
A car park opposite Sandy Glade Caravan
Park on Coast Road is provided for visitors
and has links to the waymarked footpaths
around the reserve. There is also access to
the reserve from Berrow Beach.
Public transport by bus, is available from
Burnham-on-Sea and Weston-Super-Mare
to Berrow stopping at Heron House, at
the southern edge of the reserve. There is
plenty to see all year round but an ideal
time would be on a warm, windless day in
June or July.
History of the sand dune system at Berrow
The sand dunes lie between the high
water mark and the Coast Road reaching
a height of 15 metres. They have been
formed from sand carried inland from the
extensive tidal flats and beaches by the
prevailing westerly winds.
Plants are essential to the development
and stability of the dunes, and a number
of different communities have become
established. The young, mobile dunes
near the sea have sparse vegetation with
hardy species such as Lyme Grass and
Marram Grass. Further inland, where
conditions are less harsh, grassland and
scrub communities can be found, on the
older fixed dunes. The scrub is
dominated by Sea Buckthorn, which was
introduced in the 1890’s, to stabilise the
dunes. It forms a dense cover over much
of the fixed dunes, and is threatening to
smother the open grassland.
During the Second World War, structures
- known as pillboxes - were built across
Somerset, including along the coast, to
offer protection for soldiers guarding the
land. One pillbox can be found in the
north western corner of the reserve and
another lies just outside the southern
boundary. More military relics include
the Victorian fort at the end of Brean
Down and the remains of gun and rocket
batteries on the islands that can be seen
from the beach -Steepholm and Flatholm.
At one time, sand from a large area of the
dune system was extracted on a
commercial basis but this stopped during
the late 1980’s. A large quantity of clay
was brought to the dunes to form a bank,
which reinforced a potential weak spot. This bank lies on the western side of the
large grassland area and runs roughly
north-south.
During the mid-1970’s, Sedgemoor
District Council began restoring the
dunes. High tides had washed away parts
of the foredunes and the wind had blown
gaps, known as blowouts, through the
dunes where the vegetation cover had
been reduced by trampling. Urgent,
remedial work was done, such as fencing
and planting. Access for cars was
restricted and pedestrians were asked to
use specific routes through the dunes.
In 1992, the council signed a
Management Agreement with Natural
England to ensure further protection and
restoration of its dune system which
became a Local Nature Reserve in 1993.
Conservation work on it continues today.
The Severn Estuary and mudflats
The River Severn is the longest river in
Britain and drains around a twelfth of the
Country’s land area, including much of
the Midlands and eastern Wales. It has the
second highest tidal range in the world,
rising and falling by
as much as 15.4m.
Where the Severn
meets the sea, the
boundary between
freshwater and
saltwater is neither
static nor clearly
defined, making the
estuarine waters salty
or brackish with the
salinity varying
according to the state of the tide.
However, the fresh and salt waters are
mixed thoroughly when the tidal wave,
known as the Severn Bore, moves up the
estuary, which it
does twice a day on
about 130 days a
year.
The Severn carries a
huge amount of
sediment with it as it
flows to the sea and
at the same time, the
tides bring material
upriver from further
along the coast.
Some of the
sediment is
deposited to form the mudflats but some
is constantly on the move, carried up and
down the estuary by the strong tides.
Mudflats are harsh places to live as the
environmental conditions are constantly
changing. Those creatures and vegetation
that can survive the challenges often do
so in huge numbers because estuarine
waters are rich in
nutrients
supporting
microscopic plants
and animals. These
organisms are
eaten by muddwellers, such as
worms and
shellfish, which in
turn are eaten by
larger animals. Vast
numbers of birds feed on the mudflats,
especially during the autumn and winter. They include waders like Oystercatchers
and wildfowl such as Shelduck, which
moult during the
summer and
over-winter on the
mudflats. These
birds cannot feed at
high tide and can
sometimes be seen
roosting on the
beach.
Rising up from
below the sand and
silt are occasional
lumps of blue clay. The remains of an
old forest, which probably covered much
of the present estuary until about 6,000
years ago, are visible at very low tide.
The Foredunes
The foredunes are the first dunes to form
in the dune system and they develop
above the line of wave-deposited debris
(strandline) where only the strongest
waves during very high tides will reach.
The strandline may slow the wind-blown
sand sufficiently so that fast-growing,
pioneering plants can start to grow. At
Berrow, Lyme grass is among the first
plants to become established. This tall
grass is able to keep pace with the sand
that accumulates around it by rapidly
growing upward and outward, slowing
the sand down and
forming a narrow line of
low dunes. The sand
accumulates even more
quickly when Marram
grass arrives. Like Lyme
grass it forms tussocks
and grows rapidly in
response to being
swamped by sand.
At this stage, the dunes
are known as “yellow” or “white” dunes
because of the areas of bare, uncolonised
sand. There is little water and few
nutrients in them and they are unstable
so only a few other plants can survive.
Among the plants that can are Sand
Sedge, Sand Couch and Sea Spurge.
However, the dunes slowly become
enriched by decaying plant material and
droppings from the rabbits that feed
here. Mosses and lichens cover the bare
ground between the plants so the dunes
are sometimes called “grey” dunes at this
stage.
Marram and Lyme grass thrive when fresh
sand is being added to the dune but die
out if the supply ceases. This can occur
when a new line of dunes forms upwind.
The loss of these grasses or excessive
trampling can leave the dune open to
wind erosion, which may be so great that
a gap (blowout) is punched through the
dune. The sand blown out of the
foredunes will accumulate downwind and
as long as it is fresh, it will be recolonised
by Marram grass and the dunes will once
again become stable. Conservation work
is being carried out to
stabilise the parts of the
foredunes which are most
prone to windblow.
Dune stabilisation can be
achieved in a number of
ways but the most
cost-effective method is
sand fencing. Fences are
built across the blow out,
at right angles to the
prevailing wind. They may be made from
wooden posts and wire netting or from
cut branches of Sea Buckthorn, woven
into the wire netting as is the case at
Berrow. Wind speed is reduced by the
fence, allowing the sand grains to drop
out and build a replacement dune.
Inland, the dunes rise to a height of about
15 metres and the crests are covered in
thickets of Sea Buckthorn, Blackthorn and
Hawthorn. In summer, the tall, yellow
flowers of the Evening Primrose can be
seen all over the foredunes.
Oystercatcher
Dragonfly
Redshank
Evening Primrose
Shelducks
Blackcap
Butterfly
Sea Buckthorn
Sanderlings
The Dune Slacks
The sand dunes lie at right angles to the
prevailing wind and form a series of
ridges, running roughly north-south, with
lower lying areas between their crests.
The long, linear depressions formed when
a length of beach has been enclosed by
newly formed dunes are known as
‘swales’, while the smaller hollows are
called “slacks”.
The slacks and swales are sheltered from
the wind and salt spray. They are often
quite damp and may support temporary
or even permanent ponds, because at
certain times of the year the water table is
not far below the surface. Also, plant and
animal remains tend to accumulate in the
slacks and this aids water retention. It
means that species which cannot tolerate
the harsher conditions on the crests of
the dunes can become established here.
Further inland, the slacks contain species
that are common to damp pasture land,
including many grasses, vetches, Hairy
Hawkbit and Stinking Iris. The pale fleshy
flowers of the parasitic Broomrape may
be seen in the summer. Many of the
plants found here provide food for the
larvae of moths. Burnet Moths may be
seen on Bird’s-foot-trefoil and their
caterpillars construct cocoons high up on
grass stems where it is difficult for
predators to reach them. The orange and
black ringed caterpillars of the Cinnabar
Moth feed on ragwort.
The insect and plant life of the slacks
attracts many different birds, such as
Blackcaps, Cuckoos and Magpies. Larks
nest amongst the grass but are more
likely to be heard than seen. Many birds
such as Linnets, Bramblings and
Chaffinches appear in the area during the
autumn and winter but nest further north
during the summer. The Long-eared
Tawny Owl preys on the many small
mammals found in the dunes.
The Fixed Dunes
The fixed dunes were once mobile like
those nearer the sea. Over time, new
dunes have formed to the seaward side
and interrupted the supply of fresh sand.
The once dominant Marram grass and
Lyme grass have been replaced by new
plant communities and thin, impoverished
soils have developed on what was raw
sand.
The fixed dune grassland is dominated by
Red Fescue Grass and the spikes of small,
yellow flowers of Lady’s Bedstraw. A wide
range of flowering plants, including
Restharrow, Bird’s-foot-trefoil and various
types of vetches and clovers, provide food
for many different moths and butterflies.
Particularly apparent during the summer
months are Common Blue and Meadow
Brown butterflies together with Cinnabar
and Six-spot Burnet moths. Many animals
can be found here, including invertebrates
like the Banded Snail.
The fixed dune grassland is rich in lowgrowing herbaceous plants and grasses
because the low levels of nutrients in the
soil prevent many other more aggressive
species from growing. The grassland was,
in the past, maintained by the grazing of
cattle and sheep. This system of
management lapsed early last century and
since then no agricultural activity has
taken place on the dunes. The absence of
grazing has encouraged the development
of scrub, except where rabbit grazing is
occurring. Rabbits are now the only large
grazing animals on the reserve and are
vital to the survival of the grassland areas.
One of the major aims of the management
of the Reserve is to preserve the species
diversity within the dune grassland, which
has been threatened by the increasing
amount of nutrients (especially nitrates) in
the soil. These come from plants like
vetches, clovers and Sea Buckthorn which
are able to convert atmospheric nitrogen
into that found in the soil and so allow
taller, more aggressive plants to thrive. This
process is being reversed by regular
cutting back, clearing and treating the
invasive vegetation. Also, the existing
grassland is mowed after the plants have
flowered and set seed.
The scrub which surrounds the grassland
is mainly composed of Sea Buckthorn, with
patches of Sallow, Elder and Hawthorn.
These bushes offer cover for a variety of
birds, including the Blackcap. Cuckoos may
be seen in the summer. The female Cuckoo
lays her eggs in the nests of many different
species, including warblers and pipits.
During the last hundred years or so, a
number of alien species have been
introduced to the area. The most obvious
of these are the Evening Primroses, whose
large yellow flowers open at night,
providing nectar for visiting moths.
The Ponds
About 20 years ago, a number of ponds
could be found in the dune slack areas.
These areas remained wet throughout
most of the year, supporting wetland
plants such as Marsh Pennywort, the less
common Narrow-Leaved Reedmace,
Meadowsweet, Wild Mint and three or
four species of orchid, including the
Heath-Spotted Orchid and the Marsh
Helleborine.
In recent years, due to a lowering of the
water table in the area, these ponds have
dried out completely or become dry
during the summer months.
Investigations have shown that the water
table exists at a depth of about half a
metre below the surface and a number of
ponds have recently been dredged. The
ponds are now beginning to re-establish
with plants
such as the
Common
Reedmace and
Gypsywort.
A rich
invertebrate
fauna is
associated with
the wetland
habitats with
fourteen
species of
dragonfly
having been
recorded in the
area, including
the Hairy Dragonfly and the Ruddy Darter.
Beetles are also well represented, with
many notable species, such as the
nationally rare Greater Silver Diving
Beetle.
The Sallow bushes growing nearby
provide protection and food for many
insects, including the larvae of the
Buff-Tip Moth and the Lackey Moth,
whose caterpillars leave a tent of silky
threads behind when they hatch. Many
smaller insects, such as Greenfly, find
Sallow a suitable food plant and
consequently, a variety of insect-eating
birds can be seen feeding around these
bushes. Two nationally rare species of
Soldier Fly are also present.
Conservation and management
Berrow Dunes has long been recognised
as an important area for nature
conservation. The Local Nature Reserve is
part of the Site of Special Scientific Interest
(SSSI) and next to the internationally
recognised and protected Bridgwater Bay.
Working in partnership since 1992,
Sedgemoor District Council and Natural
England have focused primarily on
revitalising the ecological interest of the
dune habitats. Their Management Plan
identified the threats to the Reserve’s
different habitats and a programme of
remedial work for them. It also
acknowledged that a lowering of the
water table in recent years had led to
some of the ponds drying out so a number
have been excavated in the hope that
water will remain in them all year round.
Conservation volunteers have
concentrated on cutting down large
quantities of scrub, mainly Sea Buckthorn,
and then treating the stumps with an
approved herbicide to limit regrowth. Since its introduction less than a century
ago, the Sea Buckthorn has spread out
over about half of the Reserve, leading to
the loss of much of the species-rich
grassland habitat.
Volunteers have also cleared scrub from
alongside the footpaths, to widen them
and prevent ‘trenches’ developing (which
can encourage erosion). The footpath
routes have been waymarked in order to
direct people to the beach and to improve
public access throughout the Reserve. The sand dunes are essentially robust but
they are at risk of being damaged by the
trampling by large numbers of visitors
during the summer months. Visitor
pressure has dramatically affected the
stability of the foredunes, particularly at
the northern end near the access road to
the beach. Traffic has been discouraged
from the dunes by the wooden bollard
barriers along the dune edge. Where
erosion has occurred within the foredunes,
sand fencing has been placed in the
blow-outs to allow sand to accumulate,
encouraging the processes of dune
formation.
A small car park exists in an area of cleared
scrub next to the Coast Road. Interpretation panels explaining the
different habitat types have been installed
here and at other places within the
Reserve.
The continued active management of the
Reserve, which is monitored and surveyed
by the Berrow Conservation Group in
order to study the processes by which the
dune habitats become re-established, will
allow the wildlife of the dunes to coexist
with our desire for informal recreation and
education.
Further information
Text:
Janette Burton, Sedgemoor District
Council
Photography:
Joe Cockram, Avalon Wildlife (birds) ©
Ken Grainger (Berrow dunes/beach) ©
Vicky Banham (Berrow dunes/beach/
flora) ©
Natural England/Peter Roworth (Sea
Buckthorn in berry) ©
Illustrations:
Mark Smith
Design: Sedgemoor Graphic Design
Acknowledgements:
The Council gratefully acknowledges the
kind assistance of Natural England,
Berrow Parish Council and Berrow
Conservation Group in the production of
this booklet.
Information Centre, South Esplanade,
Burnham on Sea, Somerset, TA8 1BU
Tel: 01278 787852
Useful websites:
www.visitsomerset.co.uk
www.somersetwildlife.org
Berrow Dunes Local Nature Reserve
Berrow, Somerset
(opposite holiday park, postcode TA8 2AX)
Sedgemoor District Council
Bridgwater House, King Square, Bridgwater, TA6 3AR