HELSINKI COMMISSION
HELCOM CORESET BD 3/2011
HELCOM CORESET Expert Workshop on Biodiversity Indicators
Third Meeting
Riga, Latvia, 15-17 June 2011
Agenda Item 4
Further development of core indicators and targets
Document code:
4/2
Date:
10.6.2011
Submitted by:
Secretariat
CANDIDATE CORE INDICATOR FOR MACROPHYTE DEPTH DISTRIBUTION
The Second HELCOM CORESET Expert Workshop on Biodiversity Indicators reviewed all
indicator proposals from working teams and classified them provisionally as candidate core
indicators, with the aim to further work with the science basis, linkage to pressures and the
target setting (Minutes of the Meeting, paragraphs 7.7-7.8). The Meeting also agreed to
develop the core biodiversity indicators to the same format as the eutrophication core
indicators on the HELCOM web site (paragraph 7.5). This document presents the candidate
core indicator for the depth distribution of macrophytes in the format of the web-based core
indicators.
The Meeting is invited to
- review the indicator,
- consider whether they should be core indicators or indicators to be published as
indicator fact sheets, and
- give advice to the working team to improve the indicator.
Note by Secretariat: FOR REASONS OF ECONOMY, THE DELEGATES ARE KINDLY REQUESTED TO BRING THEIR OWN
COPIES OF THE DOCUMENTS TO THE MEETING
Page 1 of 13
HELCOM CORESET BD 3/2011, Document 4/2
Macrophyte maximum depth distribution
The indicator for the maximum depth distribution of macrophytes was suggested by the
CORESET BD 2/2011 as a key indicator for the benthic communities. It is an indicator, which
has gone through scientific testing in many countries and has been intercalibrated in the EU
WFD Baltic GIG group. The indicator is assessed by national methods, which ensures
compatibility to EU WFD reporting. It focuses however only on depth distribution, not taking
into account other parameters, which have been used in the biological quality element of
macrophytes under the WFD. To avoid misunderstandings between these two frameworks, it
is suggested that WFD macrophyte BQE results will be shown as an additional information
under this indicator.
This version of the candidate core indicator has not been yet finalized, even though it has
been placed on the web format of the core indicators. Further work is required by experts to
finalize this indicator and to ensure correct methodology for the assessment.
[Main page]
How deep do macrophytes grow?
Key message
Macrophyte maximum depth is good in many areas of the Baltic Sea, but in
many areas, especially in the southern parts, the good environmental status has not been
acheived.
STATUS CLASS
HIGH
GOOD
MODERATE
POOR
BAD
Figure 1. Status
classifications of
macrophyte maximum
depth limits. Majority of
the classifications are
based on bladderwrack
(Fucus vesiculosus), but
also eelgrass (Zostera
marina) and the red alga
Furcellaria lumbricalis
have been used. The
targets are given for each
coastal water type and
intercalibrated in the
Baltic Intercalibration
Group under the EU
Water Framework
Directive. Note that data
from several areas is still
missing.
Page 2 of 13
HELCOM CORESET BD 3/2011, Document 4/2
Policy relevance
Eutrophication in the Baltic Sea has decreased the water transparency all over the sea
area and consequently the growing depth of benthic plants has decreased. Since many of
the larger aquatic plants are important habitat-forming species, this indicator reflects the
extent of many habitats and, hence, the status of biodiversity in coastal shallow waters.
Depending on macrophyte species, these habitats host a rich community of invertebrates
and fish and provide feeding and breeding grounds for species on higher trophic levels.
This core indicator is used also in the ecological status classifications under the EU Water
Framework Directive and its class boundaries have been intercalibrated by the Baltic
Intercalibration Group. The boundary between the good and the moderate status has
been set to reflect the good environmental status (GES) of the EU Marine Strategy
Framework Directive (MSFD).
The maximum depth limit of macrophytes assesses the HELCOM ecological objectives of
“Natural distribution of plants and animals”, “Viable populations of species” and “Thriving
communities of plants and animals”. The first one referring to the eutrophication segment
and the two latter ones to the nature conservation segment of the Baltic Sea Action Plan.
The core indicator applies also to the GES descriptor 1 (extent and condition of
populations, communities and habitats), 5 (effects eutrophication) and 6 (condition of
benthic communities) of the MSFD (Anon. 2010).
Authors
[All people and their institutes involved in developing the core indicator]
References
Anon. (2010) Commission Decision 2010/477/EU adopted by the Commission on 1
September 2010.
CIS (2003) Common Implementation Strategy for the Water Framework Directive
(2000/60/EC). Overall approach to the classification of ecological status and
ecological
potential.
Guidance
document
No
13.
Available
at:
http://europa.eu.int/comm/environment/pubs/home.htm
Krause-Jensen, D., Sagert, S., Schubert, H. & Boström, C. (2005) Empirical
relationships linking distribution and abundance of marine vegetation to
eutrophication. Ecological Indicators 8: 515-529.
Page 3 of 13
HELCOM CORESET BD 3/2011, Document 4/2
[1st sub-web page]
Maximum depths of macrophytes and temporal trends in the data series
This section misses more detailed description of the status and possibly temporal trends,
if available. This text requires “expert-level” details.
Key messages
The time series data is scarce and does not give an overall picture of the development of
the indicator. Locally, macrophytes have been observed to recolonize deeper areas, but
also opposite development has been observed.
A.
B.
Figure 2 showing GES boundary(A) and depth data (B) behind the status assessment.
[Text of the growing depths in different parts of the Baltic Sea, linking the development
also to the status maps on the main web page].
A.
B.
C.
D.
Figure 3 explaining basic information of the time series figures.
[Text of the temporal development in different parts of the Baltic Sea, linking the
development also to the status maps on the main web page].
References
[references to back-up the text above if different from the main page’s references]
Page 4 of 13
HELCOM CORESET BD 3/2011, Document 4/2
[2nd sub-web page]
Effects of anthropogenic pressures on the macrophyte depth limit
Increase of
nutrients
Other eutrophication-related factors
affecting the decline of macrophytes:
 increased herbivory
 increased organic matter
 competition with annual algae
Increase of
phytoplakton
Reduced water
transparency
Shift of benthic
plants upwards
Reduced habitat extent for
invertebrates and fish. Cascading
consequences for the trophic web.
Figure 4. Conceptual model of the impact of anthropogenic pressures on macrophyte
depth distribution and consequences to biodiversity.
Relevance of the indicator for describing the developments in the environment
The correlation between macrophyte depth distribution and reduced water transparency is
one of best known indirect effects of eutrophication in the Baltic Sea. It was first described for
bladderwrack (Fucus vesiculosus) 20-30 years ago (Kangas et al. 1982, Kautsky et al. 1986),
but later it has been also shown for other macroalgae and vascular plants (Nielsen et al.
2002, Dahlgren & Kautsky 2004, Krause-Jensen et al. 2005, Rosqvist 2010).
Bladderwrack is especially sensitive to eutrophication as the water transparency is not the
only factor reducing its depth distribution. Also competition with ephemeral algae and
mussels (both benefiting of slight eutrophication) and increased sedimentation of organic
matter may limit its depth distribution (Eriksson & Johansson 2003). Sedimentation of organic
matter increases as a result of increased phytoplankton abundance and it covers hard
substrata in deeper zones were wave motion does not disturb it.
In sheltered soft-bottom areas, such as coastal lagoons, vascular plants can grow even at
the depth of several meters and increased nutrient concentrations have been shown to
cause a local regime shift from phytobenthos dominated community to a phytoplankton
dominated one. Such a change reduces the extent of phytobenthos habitats, which are
important spawning areas of fish and feeding areas of coastal birds.
The maximum depth limit of perennial macrophytes, such as bladderwrack and eelgrass, has
been shown to correlate well with nutrient concentrations (Nielsen et al. 2002, KrauseJensen et al. 2005, Carstensen et al. 2008). As perennial species, they are however slow to
respond to changes in nutrient levels. The slow responses are mainly due to slow growth
rates, short colonization distances of reproductive propagules or lack of suitable new growth
substrates. There are however clear observations of recolonization of, for example,
bladderwrack in areas, where it was lost due to coastal eutrophication (Nilsson et al. 2004).
The most important, habitat forming species at the Eastern Baltic Proper coast is the red alga
Furcellaria lumbricalis. Dense stands of this species have an important role in providing
spawning substrate for fish, shelter for fish fry and supporting high marine biodiversity. Due
to commercial value of Furcellaria, its stock assessment was performed in late 1950s-1960s
in the Lithuanian coast (Kireeva, 1960a,b; Blinova, Tolstikova, 1972 cited by Daunys D., et
al., 2007). Thus, this is the only phytobenthos species for which the historical record dates
back to the pre-eutrophication time. The water quality assessment criteria were established
comparing the historical data with patterns of recent distribution of F. lumbricalis in the
Lithuanian coastal waters.
Page 5 of 13
HELCOM CORESET BD 3/2011, Document 4/2
References
Bäck, S. & Ruuskanen, A. 2000. Distribution and maximum growth depth of Fucus
vesiculosus along the Finnish coastline. Marine Biology 136: 303-307.
Carstensen J, Krause-Jensen D, Dahl K, Henriksen P. 2008. Macroalgae and phytoplankton
as indicators of ecological status of Danish coastal waters. Danmarks Miljøundersøgelser,
Aarhus Universitet, 2008. 90 s. (NERI Technical Report; No. 683)
Dahlgren, S. & L. Kautsky (2004): Can different vegetative states in shallow coastal bays of
the Baltic Sea be linked to internal nutrient levels and external nutrient load?
Hydrobiologia 514:243-248.
Eriksson, B.K. and Johansson, G. 2003. Sedimentation reduces recruitment success of
Fucus vesiculosus (Phaeophyceae) in the Baltic Sea. European J. Phycol. 38, 217–222.
Kangas, P., Autio, H., Hällfors, G., Luther, H., Niemi, Å. & Salemaa, H. 1982: A general
model of the decline of Fucus vesiculosus at Tvärminne, south coast of Finland in 197781. - Acta Bot. Fennica 118: 1-27,
Kautsky, N., Kautsky, H., Kautsky, U. & Wærn, M. 1986. Decreased depth penetration of
Fucus vesiculosus (L.) since the 1940's indicates eutrophication of the Baltic Sea. Marine
Ecology Progress Series 28: 1-8.
Krause-Jensen, D., Sagert, S., Schubert, H. & Boström, C. (2005) Empirical relationships
linking distribution and abundance of marine vegetation to eutrophication. Ecological
Indicators 8: 515-529.
Nielsen SL, Sand-Jensen K, Borum J, Geertz-Hansen O (2002) Depth colonization of
eelgrass (Zostera marina) and macroalgae as determined by water transparency in
Danish coastal waters. Estuaries 25:1025–1032
Nilsson, J., Engkvist, R. and Person, L.-E. 2004. Long-term decline and recent recovery of
Fucus populations along rocky shores of southeast Sweden, Baltic Sea. Aquatic Ecology
38, 587–598.
Rosqvist, K. (2010) Distribution and role of macrophytes in coastal lagoons: Implications of
critical shifts. Doctoral thesis. Department of Biosciences, Husö Biological Station,
Environmental and Marine Biology, Åbo Akademi University. Available at:
http://www.doria.fi/bitstream/handle/10024/66626/rosqvist_kajsa.pdf?sequence=1
Torn, K., Krause-Jensen, D. & Martin, G., 2006. Present and past depth distribution of
bladderwrack (Fucus vesiculosus) in the Baltic Sea. Aquatic Botany 84, 53-62.
Page 6 of 13
HELCOM CORESET BD 3/2011, Document 4/2
[3rd sub-web page]
Technical data on the macrophyte depth distribution core indicator
Data source
National monitoring programmes of the EU Member States in the Baltic Sea area.
Description of data
Denmark: Depth distribution of at least 10% coverage of Zostera marina.
Estonia: Depth limit single Fucus vesiculosus plants.
Finland: Lower depth limit growing zone of Fucus vesiculosus. Reference: Guidelines for
measuring the lower growth limit of the Fucus vesiculosus belt. Draft report by
Ari Ruuskanen.
Germany: ELBO index for shallow soft-bottom inner coastal waters measures depth
distribution (belt of at least 10% coverage) of angiosperms and charophytes.
BALCOSIS index for open coasts measures depth distribution (belt of at least
10% coverage) of Zostera marina (from 50 shoots/m2) and Fucus spp., Fucus
abundance (% dominance cover) in the Fucus zone (0-2 m depth). Reference:
Steinhardt et al. 2009.
Latvia: Fucus vesiculosus and Furcellaria lumbricalis present. Data missing.
Lithuania: Maximum depth limit of Furcellaria lumbricalis in the open coast and maximum
depth limit of potameids in the Curonian lagoon.
Poland: Macrophyte monitoring in Puck Bay. Data missing.
Sweden: Multispecies maximum depth index (3-9 species). Macroalgae used in most
areas. In the Bothnian Bay and other low salinity areas Charophytes and
vascular plants were used.
Geographic coverage
The geographical coverage of this core indicator is adequate, once national monitoring
programmes for the implementation of the EU Water Framework Directive will be finalized
and monitoring started. Currently, the monitoring data is scattered and in some areas the
indicator result may have low quality before longer time series have been collected.
Latvia, Poland and Russia have not provided data to support this indicator.
Temporal coverage
Data covers mainly the time period 2005-2010, but in Swedish coast there are sites where
assessment is based on data from 1997-2000.
The indicator aims at annual data, but less frequent data may be also adequate as the
changes in the depth distribution may take several years.
Harmonization of the sampling method could be considered.
Methodology and frequency of data collection
See references for methods above, under the heading “Data description”.
Methodology of data analyses
See references for methods above, under the heading “Data description”.
Strengths and weaknesses of data
The core indicator covers potentially the whole coastal Baltic Sea, because the depth
distribution of macrophytes can be measured in all coasts. Another strength is the wide
array of species, which respond similarly to the change in the environment and can,
hence, be included in the indicator. The boundary to GES has been intercalibrated among
the Baltic countries (excl. Russia), even though the target setting methods have differed
among countries and areas.
Page 7 of 13
HELCOM CORESET BD 3/2011, Document 4/2
The quality of the core indicator will improve with addition of more species (e.g. red algae)
and with possible addition of offshore reefs to the indicator. Currently, there are no target
levels set for offshore reefs. Including Latvia, Poland and Russia (Leningrad region and
Kaliningrad region) to the indicator will increase geographical coverage.
Target values and classification method
Reference values and classification can be achieved by light models and/or historical data
but the direct correlation of the indicator to the pressure can be interfered by biological
competition for space. Targets have been intercalibrated in the EU expert group for Water
Framework Directive „Baltic GIG‟. They are based on old data sets (Reference conditions
+ Acceptable deviations) and expert judgment. Targets for some species have been
estimated on the basis of wide datasets in varying environmental conditions.
Basis for setting of reference conditions. From: Baltic GIG milestone report no 4.
Country
Type and period of
reference conditions
Germany
ELBO
Historical data starting in
No currently existing
1880 for plant communities.
sites.
Modelling (extrapolating
About 20 historical data
model results) of depth limits
sites.
(Light model)
Germany
BALCOSIS
Estonia
Poland
Sweden
Number of reference
sites
Location of
reference sites
Reference criteria used for
selection of reference sites
whole German Baltic
inner coastal water No selection of current sites, only
historical sites.
(soft bottom
Historical data from 1880-1930 as
dominated), but less
assumed period with very low
sites for the western anthropogenic impact
inner bays
Historical data starting 1889
No currently existing
No selection of current sites, only
for depth limits, species
No currently existing
sites.
historical sites.
reduction.
sites.
Whole German
Historical data from 1890-1930 as
Modelling (extrapolating
About 16-20 historical Baltic outer coastal
assumed period with very low
model results) of depth limits data sites
water, but less sites anthropogenic impact
(Light model).
east of the Darß Sill.
Suitability of historical data for
Whole territorial sea: determination of reference conditions
was decided based on assumption
Expert knowledge, Historical
Northern Gulf of
data from 1959-1973
Approx. 500 historical Riga, southern part that actual level of human impact on
the coastal sea during this historical
(summer months), some
data sites.
of Gulf of Finland,
period (1960s) as very low
modelling.
Estonian
(especially in the area of West
Archipelago Sea,
Estonian Archipelago and waters
facing the Baltic Proper).
Pre-industrial times, low
concentration of nutrients; Biological
criteria:
High biomass of "positive" taxa
angiosperms and/or macroalgae ,
TW:, Expert knowledge,
presence of Fucus vesiculosus and
Historical data from the inner
Furcellaria lumbricalis (aegagrophila
No currently existing
Puck Bay (Puck Lagoon):
form)
sites.
1950s (pre-industrial period),
Absence/low biomass of species
Historical reference site: Northern Poland
Data between 1957-2009
regarded as "eutrophication
inner Puck Bay (Puck
(June – September) used for
indicators", negative taxa, i.e.:
Lagoon )
Pilayella littoralis, Ectocarpus
the classification
siliculosus, Cladophora glomerata,
development
Chaetomorpha linum, Enteromorpha
sp.,
ref = 50% of index value noted in 50s
(6.61), i.e. 3.3
Expert knowledge, Historical No actual reference
Two data sets from
Not provided
data (1940-ties), Least
sites
the 1940-ties, one in
Page 8 of 13
HELCOM CORESET BD 3/2011, Document 4/2
Basis for setting of reference conditions. From: Baltic GIG milestone report no 4.
Country
Type and period of
reference conditions
Number of reference
sites
Disturbed Conditions
Denmark
Eelgrass
depth
Finland
Lithuania
Location of
reference sites
Reference criteria used for
selection of reference sites
the Gräsö region,
Åland Sea and one
in Gullmaren,
Swedish west coast.
The historical data
Historical data (1883-1929)
are distributed
around year 1900: eelgrass A large net of historical across most of the
meadows covered most of data amounting to
Danish coastal
the Danish coastal waters several hundred in total waters / fjords with
and grew deep
the majority along
the open coasts
It was assumed that the period
1880s-1920s represented a period
with low nutrient loads characteristic
of reference conditions. Moreover, as
the majority of the Danish eelgrass
populations were killed by the widespread 'wasting disease' in the early
1930s we used data before 1930 to
describe the reference.
Expert judgment: on data
None actual reference
from 1993-2010 and historic
sites.
data
Historical data on nutrients, secchi
depth and Fucus
There are no reference sites.
Historical data (historical
data from before 1959's
Single note from
and1968) based on expert literature 1968
knowledge (Minkevicius,
Pipinis, 1959).
Northern CW: maximum depth record
of the red algae Furcellaria
lumbricalis at the Lithuanian coast
late 1950s: 19 m (Kireeva,1960). >20
m depth limit is used as reference
conditions at CW.
Sites from exposed TW: the maximum depth records of
the red algae Furcellaria lumbricalis
part of the eastern south off Palanga in late 1950s,
Baltic considered
when the species was found in
and Northern and depths of 17 m (Kireeva, 1960) with
central parts of the patterns of recent distribution of F.
lumbricalis. >18 depth limit is used as
Curonian lagoon.
reference conditions for TW (plume
of the Lagoon in the Baltic Sea).
Biological criterium from literature:
Maximum depth limit of potameids is
more than 3.0 m (reference defined +
20 percentage)
Basis for defining the class boundaries for High status, Good status and Moderate status.
Member State
Germany
ELBO
Type of boundary setting:
Expert judgment –
statistical – ecological
discontinuity – or mixed
for different boundaries?
Using discontinuities in the
relationship of
anthropogenic pressure and
the biological response.
For the latter for each subwater type a “degradation
chain” was defined,
describing which vegetation
types are considered to
prevail in the five classes
(normally from certain Chara
species at high status to “no
Specific approach for
H/G boundary
Changes in vegetation
association structure – the
lack of specific charophyte
communities
The eco-physiological light
demands of angiosperms
were assumed to be 10 %
for charophytes to be 40 %
of the surface irradiance
(SI). Reference values are
Page 9 of 13
Specific approach
for G/M boundary
BSP: method tested
against pressure
Changes in vegetation
association structure –
the lack of specific
charophyte
communities and 5%
No, but is currently being
light reduction for
conducted
depth limits of
angiosperms and 25
% light reduction for
depth limits of
HELCOM CORESET BD 3/2011, Document 4/2
Basis for defining the class boundaries for High status, Good status and Moderate status.
Member State
Germany
BALCOSIS
Estonia
CW
Poland
CW & TW
Type of boundary setting:
Expert judgment –
statistical – ecological
discontinuity – or mixed
for different boundaries?
vegetation at all” at bad
status). The specific depth
limits for certain water types
were modelled by a salinitydependent calculation of
water transparency and,
thus, light levels at certain
depths.
The boundaries for depth
distribution of the 2 species
were calculated based on
light reduction in percent
from the known depth limit
of both species (10m) and
the total light requirement
over the vegetation period
(10% SI).
At least 25% reduction =
poor status and >75% bad
status.
For all other factors
reference values were set
by the evaluation of
historical data and
boundaries were set upon
expert knowledge and
ecological discontinuity.
Boundaries have been
st
adjusted from the 1
intercalibration exercise for
eelgrass depth limits. The
intercalibrated reference
value is now 9.4 m.
BSP used is based on
concept of Acceptable
Deviation described in
Andersen et al. 2006 and
2010 and also used in
HELCOM Eutrophication
assessments (HELCOM
2006, 2009
Expert judgment,
Poor = 70-90% deviation
from reference
Bad = >90% deviation from
reference
Specific approach for
H/G boundary
site specific set by
historical data or by a light
model. 1% light reduction
represents the transition
from the high/pristine to
good ecological status for
the depth limits of
charophytes and
angiosperms
Specific approach
for G/M boundary
BSP: method tested
against pressure
charophytes
represents the
transition from good to
moderate status
1% light reduction
represents the transition
from the high/pristine to
good ecological status for
depth limits.
For biomass of
opportunists ≤1% vs. >1%
represents the transition
from the high/pristine to
good ecological status.
For species reduction a
reduction from 9-10
defined taxa to 7-8
represents the transition
from the high/pristine to
good ecological status.
For Furcellaria biomass a
reduction from ≥30% to
below 30% represents the
transition from the
high/pristine to good
ecological status.
For Fucus abundance a
reduction from ≥75% cover
to below 75% represents
the transition from the
high/pristine to good
ecological status.
5% light reduction
represents the
transition from good to
moderate status for
depth limits
For biomass of
opportunists ≤10% vs.
>10% represents the
transition from good to
moderate status.
For species reduction
a reduction from 7-8
defined taxa to 4-6
represents the
transition from the
Yes – Quantitative
good to moderate
(documentation available
status.
in German)
For Furcellaria
biomass a reduction
from ≥20% to below
20% represents the
transition from the
high/pristine to good
ecological status.
For Fucus abundance
a reduction from
≥50% cover to below
50% represents the
transition from the
high/pristine to good
ecological status
High status: 0-20%
deviation from reference
G/M boundary is set
through acceptable
deviation standard of
50 %.
High status:0-10%
deviation from reference
Good status = 10-40%
deviation from reference
Page 10 of 13
Moderate status= 4070% deviation from
reference
Yes, documentation
provided in file:
Pressure_Estonia.pdf
No
HELCOM CORESET BD 3/2011, Document 4/2
Basis for defining the class boundaries for High status, Good status and Moderate status.
Member State
Sweden
CW
Denmark
Seagrasses
Type of boundary setting:
Expert judgment –
statistical – ecological
discontinuity – or mixed
for different boundaries?
Boundaries are set at two
levels, scoring boundaries
for selected species and
index boundaries. Scoring
boundaries are set in
relation to reference depth
limits for each species
based on expert
judgement, index (mean
score) boundaries are just
an equidistant division of
the EQR gradient into five
classes.
Historical data
Historical data (on nutrient
load) in combination with
Denmark
modelling (of nutrient
Macroalgal
concentration based on
cover,
loads and of algal variables
No. of perennial
on nutrient concentration
sp. , ratio of
and salinity) were used to
opportunists
define reference levels and
boundaries.
Finland
CW
Lithuania
CW & TW
Calibrated against preclassified sampling sites
Expert judgment, the same
for CW and TW:
Specific approach for
H/G boundary
Specific approach
for G/M boundary
BSP: method tested
against pressure
Not provided
Not provided
Yes theoretically very
well documented with
lots of data on depth
distribution against
pressure (see KrauseJensen et al 2008
doi:10.1016/j.ecolind.20
07.06.004). Index
against pressure not
tested.
Eelgrass depth limits have
been shown to respond to
changes in water clarity
which again relates to
nutrient levels. Historical
data on depth limits from a
period with high water
clarity (1880-1930) and low
nutrient levels were used to
characterise the reference
situation The reference is
defined as the 90%
percentile of historical data.
The H/G boundary is at an
EQR value = 0.9
At good status the
eelgrass meadows
grow deep, deviating
only by 26 % from
reference depth limits
corresponding to a
Good/ moderate
boundary with EQR =
0,26 as
Intercalibrated in
phase 1
We assumed that the
We used the period around period around 1965
represented the G/M
year 1900 as reference
boundary. Based on
period. Nitrogen loads from TN loads from this
1900, corresponding
period we derived
corresponding TN
nitrogen concentrations
concentrations and
and salinity of the area in
entered these along
question were entered in a with the salinity for the
linear regression model to area in question in the
calculate the
linear regression
corresponding level of algal model that then
provided the
variables.
corresponding level of
algal variables.
The maximum depth
distribution of Fucus
The maximum depth
for G/M boundary by
distribution of Fucus for
evaluation of historic
high EQR by evaluation of
data
historic data
Northern CW: High status
is defined according to the
maximum depth record of
Page 11 of 13
Northern CW:
G/M boundary is set
Yes:
Quantitative
but for less than 26 %
deviation from the
reference
Yes
Quantitative
No
No
HELCOM CORESET BD 3/2011, Document 4/2
Basis for defining the class boundaries for High status, Good status and Moderate status.
Member State
Lithuania
TW
Type of boundary setting:
Expert judgment –
statistical – ecological
discontinuity – or mixed
for different boundaries?
Poor status is defined by the
maximum depth record
within the 5-9 m range (4-9
TW), which is classified as a
critical limit determining loss
of dense overgrowths at
lower depths.
Bad status is defined by the
maximum depth limit at less
than 5 m (4m TW), which is
considered as a very high
risk of F. lumbricalis
extinction at the Lithuanian
coast due to competition
with opportunistic
filamentous algae, reduced
area of available substrate
and strong wave effect.
Reference conditions:
Maximum depth limit of
potameids is more than 3.6
m. Moderate status has
been defined as recent
depth limit of potameids.
Other classes have been
defined taking into account
degradation of potameids
belt in zones of active
hydraulic process
Specific approach for
H/G boundary
Specific approach
for G/M boundary
these red algae at the
Lithua-nian coast late
1950s: 19 m (Kireeva
1960). H/G boundary is set
at 10% from reference.
Good status is defined by
the maximum depth record
within the 15-19 m, a range
which generally
corresponds with recent
distribution of F.
lumbricalis.
TW good status: H/G
boundary is set at 6% from
reference. Between 14 to
17 m range for transitional
waters which generally
corresponds with recent
distribution of F. lumbricalis
These limits did not change
significantly during the
recent five decades (Olenin
et al. 2003; Bucas et al., in
press; unpublished data
cited by Daunys et al.
2007).
at 25% deviation from
reference. Moderate
status is defined by
the maximum depth
record within the 9-15
m range (up to 55%
from reference). It is
suggested that
decline of depth limit
up to 15 m will result
in subsequent
reduction of the most
valuable dense
overgrowths at lower
depths, which may be
interpreted as habitat
alteration. If the
maximum distribution
depth will decline to 9
m it is unlikely that the
dense overgrowths at
lower depth will
survive.
TW: G/M boundary is
set at 22% deviation
from reference
Moderate status = 914m
High status - depth limit 3,0
m (Minkevicius; Pipinis
1959).
Moderate status has
been defined as
recent depth limit of
potameids.
BSP: method tested
against pressure
No
Further work required
See recommendations under “Strenghts and weaknesses”.
References
Steinhardt, Tim, Rolf Karez, Uwe Selig & Hendrik Schubert (2009): The German
procedure for the assessment of ecological status in relation to the biological quality
element “Macroalgae & Angiosperms” pursuant to the European Water Framework
Directive (WFD) for inner coastal waters of the Baltic Sea. Rostocker Meeresbiologische
Beiträge, 22: 36 pp. Available at: http://www.biologie.uni-rostock.de/oekologie/RMB.htm
Page 12 of 13
HELCOM CORESET BD 3/2011, Document 4/2
[4th sub-web page]
Data set on the macrophyte depth distribution in coastal water areas
Links to excel files with the data.
Page 13 of 13