CENTRAL BALTICLAkeGIG – Benthic FAUNA

1. Methods and required BQE parameters

MS / Full BQE method / Taxonomic composition / Abundance / Disturbance sensitive taxa / Diversity / Combination rule of metrics
BE/FL / yes / number of EPT taxa; number of other sensitive taxa / Rel. abundance included / number of EPT taxa;
number of other sensitive taxa; mean tolerance score / Shannon-Wiener diversity index;
total number of present taxa;
number of EPT taxa;
number of other sensitive taxa / Average metric scores
EE / yes / EPT taxa richness / Rel. abundance included / EPT taxa richness;
ASPT index;
Swedish Acidity index / Shannon diversity;
total taxa richness / Average metric scores
DE / yes / Rel. Abundance of Odonata;
Rel. abundance of habitat typeLithal (% of abundance classes)
Rel. abundance of Chironomidae (% of abundance classes) for riverine lakes / Rel. abundance included / Faunaindex / Number of ETO-Taxa;
Margalef-Diversität
for riverine lakes / Average metric scores
LT / yes / number of EPTCBO-taxa
Rel. Abundance of EPC-taxa / Rel. abundance included / ASPT index / Shannon diversity / Average metric scores
NL / yes / KM% = rel. number of typical (for watertype) species in a sample
%DN = rel. abundance of dominant negative species
%DP = rel. abundance of dominant positive species / Rel. abundance included / See tax. comp. / KM% = rel. number of typical (for watertype) species in a sample. This metric is highly correlated with numer of taxa / Weighted averaging of metrics
UK / yes / Chironomid Pupal Exuviae Technique (CPET) / No (see footnote) / CPET / No (see footnote) / Not applicable

Footnote UK: CPET has a strong relationship to the pressure gradient for N and P ( r2 = 0.78),thisoftenbeing greater that that ofother benthic invertebrate metrics that include abundance and diversity indices.The inclusion of pure taxa richness and diversity metrics was tested, but resulted in significantly poorer correlations with the stressor

MemberState / Methodology used to derive the reference conditions
BE/FL / Expert judgement (based on data and expert validation)
EE / Existing near-natural reference sites, expert knowledge, least disturbed conditions
DE / Modeling (extrapolation, percentiles) combined with expert-judgement
LT / Percentiles based on existing near-natural reference sites, expert knowledge
NL / Expert knowledge, historical data, least disturbed conditions(no actual existing natural sites in lakes)
UK / Existing near-natural reference sites, expert knowledge, historical data, modeling (extrapolating model results)

3. National boundary setting

MemberState / Methodology used to set class boundaries
BE/FL / Boundaries used for most river types (resulting from intercalibration exercise) are applied to lakes as well
EE / Boundaries used for most river types (resulting from intercalibration exercise) are applied to lakes as well.Boundaries were adjusted by expert judgement based on pre-classified sampling sites
DE / Equidistant division of the EQR gradient
LT / Equidistant division of the EQR gradient
NL / Equidistant division of the EQR gradient, expert validation procedure
UK / CPET: Using paired metrics (percent relative frequency of sensitive and tolerant species) that respond in different ways to the influence of the pressure (GM boudary); other boundaries by equidistant division and expert judgement

4. Pressures-response relationships

MemberState / Metrics tested / Pressure / Pressure indicators / Strenght of relationship
BE/FL / Multimetric Index / Not tested for lakes yet, see footnote / - / -
EE / Multimetric Index / Hymo
Eutro / Phytoplankton quality, natural and semi natural landuse, tP / Phytoplankton: R2 = 0,33 (n=20)
Landuse: R2 = 0,41 (n=20)
tP: R2 = 0,1 (n=14)
DE / Multimetric Index (AESCHNA) / Hymo
(Eutro) / several morphological parameters, nutrients and trophic status / Morphology: R2 = 0.1 – 0.25 (significant)
Eutrophication: R2 <= 0.1 (some significant)
LT / Multimetric Index / (Hymo)
Eutro / tP, tN, chlorophyl-a, BOD / BOD: significant (Spearman)
NL / WFDi / Hymo
(Eutro) / Shore alteration%, Shore artificial%, Shore natural vegetation%, tP / Shore alteration%: R2 = 0,45 (n=32)
Shore artificial%: R2 = 0,15 (n=32)
Shore natural vegetation%: R2 = 0,16 (n=32)
tP: higher metric scores (>0,5) only at tP <0,1 mg/l
UK / CPET / Eutro / pressure metric: tN / mdepth * tP / R2 = 0,78 (n=166)

Footnote BE: Relationship was thus far only tested for rivers; it is assumed that the relationship is similar for lakes but this was not tested yet