Phytoplankton
Summary text
Eastern Continental GIG
1. Description of national assessment methods
Two methods participate in the IC:
· HU: Hungarian lake phytoplankton index (HLPI)
· RO: Romanian Assess. Method for Ecological Status of the Water Body (natural lakes) based on Phytoplankton (RO-NL-PHP)
Member State / Method / StatusHungary / The composition metric is published: Padisák J, Borics G, Grigorszky I, et al. (2006): Use of phytoplankton assemblages for monitoring ecological status of lakes within the Water Framework Directive: the assemblage index Hydrobiologia 553: 1-14
Biomass metric has also been developed. It is available in English / intercalibratable finalized method
Romania / Romanian phytoplankton index, based on number of taxa, ID (Shannon), ratio of Cyanobacteria, total biomass, and Chl-a.
Description available in English (Annex)
The ratio of cyanobacteria as bloom metric is incorporated in the multimetric index. / intercalibratable finalized method
Methods and required BQE parameters
Assessment metrics for parameters (se-parate single metrics or multimetric) / A multimetric index, which consists of two single metricsAbsolute abundance of cyanobacteria is also considered as bloom metric / A multimetric index, which is based two biomass, two diversity and a bloom metric. /
National method Abundance parameter + Computation details / Chlorophyll-a metric is calculated. Boundaries are set for the metric, and based on these normalised EQRs are calculated / Two metrics are calculated: Chlorophyll-a metric and biomass metric based ont he biovolume of the taxa. Boundaries are set for the metrics and, based on these normalised EQRs are calculated /
National method Diversity parameter + Computation details / Diversity is not considered / Two diversity metrics are calculated: species number and Shannon diversity. Boundaries are set for both metrics, and based on these, normalised EQRs are calculated /
National method Parameter distur-bance sensitive taxa + Computation details / The applied composition metric is based on the “Assemblage index” (Q) published by Padisák et al. (2006). Q is given as
pi: the relative contribution of the ith functional group to the total biomass, F: is a factor number that is based on the distribution of functional groups of algae along a pressure scale. Boundaries are set for the metric and, based on these normalised EQRs are calculated / Relative biomass abundance of Cyanobacteria. Boundaries are established and based on these a normalised metric is calculated. /
Combination rule for multimetrics /
HLPI: Hungarian lake phytoplankton index
EQRQ : normalised EQR of the composition metric
EQRChl-a : normalised EQR of the biomass (Chlorophyll-a metric). This value is modified if Cyanobacteria biomass > 10 mgl-1 / Romanian phytoplankton Index = 0.05×TAX+0.2×CYANO+0.2×BIO+0.5×CHL+0.05×ID
Tax: number of taxa
Cyano: relative abundance of cyanobacteria:
BIO: absolute biomass
Chl: chlorophyll-a
ID: Shannon diversity /
HU: Biomass metric and composition metric has been elaborated. The index is the weighted average of this two metrics.
As a bloom metric the use of the absolute abundance of cyanobacteria is applied.
RO: Composition, biomass and bloom metric is incorporated in the multimetric index. During the calculation of the index different weighting factors are used.
The relative abundance of cyanobacteria is one of the composition metrics in the RO multimetric index.
For scientific literature and computation details see table in annex
Sampling and data processing
Member State / Sampled period / Sample number / Sampled layer / Sample processing / Biomasscalculation
Hungary / Vegetation period (June- September) / ≥4 / Zmax<3m: the whole water column
Zmax>3m: photic zone / Utermohl technique, (400 units are counted) / based on cell measurements using approximate dimensions from geometric formulae
Romania / Vegetation period (June- September) / ≥4 / Zmax<3m: the whole water column
Zmax>3m: photic zone / Utermohl technique (400 units are counted) / based on cell measurements using approximate dimensions from geometric formulae
National reference conditions
Table summarises the methodology used to derive the reference high status or the H/G boundary
Member State / Historical abiotic data / Hind-casting of abiotic data / Recent abiotic / biotic relationshipHungary / – / – / Chlorophyll-a, Secchi depth and depth of oxygen depletion
Romania / – / – / Chlorophyll-a, Secchi depth and depth of oxygen depletion
National boundary setting
Table : overview of the methodology used to derive reference conditions and H/G and G/M boundaries
Member State / Referenceconditions / H/G boundary / G/M boundary
Chl-a metric / Composition metric(s) / Chl-a metric / Composition metric(s)
Hungary / Expert judgement / Chl-a concentration at which the oxygen depletion might occur in 4ms depth / Relationship between the values of the multimetric anthropogenic stressor and the composition metric showed distinct discontinuity. The value where the decreasing tendency starts was considered as H/G boundary / Chl-a concentration at which the oxygen depletion might occur in 3ms depth. (This value is identical with the max. of the benchmark lakes) / Relationship between the values of the multimetric anthropogenic stressor and the composition metric showed distinct discontinuity. The middle section of the slope was considered as G/M boundary
Chl-a metric / Multimetric index / Chl-a metric / Multimetric index
Romania / Expert judgement / Chl-a concentration at which the oxygen depletion might occur in 4ms depth / The boundaries of the specific metrics were set by expert judgement. The final setting of the multimetric index is based on the relationship between the values of the multimetric anthropogenic stressor and the index (The value where the decreasing tendency starts was considered as H/G boundary) / Chl-a concentration at which the oxygen depletion might occur in 3ms depth. (This value is identical with the max. of the benchmark lakes) / The boundaries of the specific metrics were set by expert judgement. The final setting of the multimetric index is based on the relationship between the values of the multimetric anthropogenic stressor and the index (The middle section of the slope was considered as G/M boundary)
National boundary setting
Table : overview of the methodology used to derive M/P and P/B boundaries
Member State / M/P boundary / P/B boundaryChl-a metric / Composition metric(s) / Chl-a metric / Composition metric(s)
Hungary / Equidistant categories / Equidistant division of the G/M-P/B range / Minimum value of the heavily impacted lakes’ population / Lowest values of the composition metric at the higher range of pressures (MAS=2-2.5)
Romania / Equidistant categories / Equidistant categories / Minimum value of the heavily impacted lakes’ population / Equidistant categories
2. Results WFD compliance checking
List of the WFD compliance criteria and the WFD compliance checking process and results
Compliance criteria / Compliance checking conclusions1. Ecological status is classified by one of five classes (high, good, moderate, poor and bad). / HU and RO use five classes for state evaluation
2. High, good and moderate ecological status are set in line with the WFD’s normative definitions (Boundary setting procedure) / Boundaries were set in line with the normative definitions of the WFD.
3. All relevant parameters indicative of the biological quality element are covered (see Table 1 in the IC Guidance). A combination rule to combine para-meter assessment into BQE assessment has to be defined. If parameters are missing, Member States need to demonstrate that the method is sufficiently indicative of the status of the QE as a whole. / Phytoplankton composition, biomass and intensity of algal-blooms were considered during the method development in case of both (HU and RO ) metrics.
4. Assessment is adapted to intercalibration common types that are defined in line with the typological requirements of the WFD Annex II and approved by WG ECOSTAT / The intercalibration was feasible only for EC -1 lakes.
5. The water body is assessed against type-specific near-natural reference conditions / In the lack of reference lakes alternative benchmark lakes were selected.
6. Assessment results are expressed as EQRs / Results are expressed as EQRs
7. Sampling procedure allows for representative information about water body quality/ ecological status in space and time / The sampling procedure makes possible the investigation of the changes of the biomass and composition of the phytoplankton in the vegetation period
8. All data relevant for assessing the biological parameters specified in the WFD’s normative definitions are covered by the sampling procedure / The necessary data (composition and biomass) are covered by the sampling procedure
9. Selected taxonomic level achieves adequate confidence and precision in classification / Taxa were identified to species level.
General conclusion of the compliance checking:
· Compliance criteria 1. up to 9. are clearly met the requirement of the normative definitions WFD.
· Difficulties with compliance criteria nr. 5 (reference conditions could be defined by expert judgement) still exist and improvements should be reported in the 3rd RBMP.
3. Results IC Feasibility checking
Description of EC1 LAKE TYPES
Typology
The intercalibration is feasible for EC-1 lakes
Method / Appropriate for IC types / subtypes / RemarksHU / EC1 lake type / Appropriateness was checked for EC1 lakes
RO / EC1 type / Appropriateness was checked for EC1 lakes
Common IC type / Type characteristics / MS sharing IC common type
EC1 Lowland very shallow hard-water / Altitude <200m
Depth< 6m
Conductivity 300-1000 (µS/cm
Alkalinity 1-4 (meq/l HCO3) / HU Yes
RO Yes
EC2 Lowland very shallow but very high alkalinity / Altitude <.200m
Depth< 6m
Conductivity >1000 (µS/cm)
Alkalinity >4 (meq/l HCO3) / HU Yes
RO No
EC3 / Altitude 200-800m
Depth <6m
Conductivity 200-1000(µS/cm)
Alkalinity 1-4 (meq/l HCO3) / HU- No
RO -Yes
EC4 / Altitude 200-800m
Depth>6m
Conductivity 200-1000(µS/cm)
Alkalinity 1-4 (meq/l HCO3) / HU- No
RO -Yes
EC5 Reservoirs / Altitude 200-800 ?m
Depth>6m
Conductivity 200-1000(µS/cm)
Alkalinity 1-4 (meq/l HCO3) / HU- No
RO -Yes
Pressures
The intercalibration is feasible in terms of pressures
Conclusion ? what pressures do MS methods address - general degradation ?
Type / Member State / Pressure or combination of pressures / Pressure indicators / Strenght of relationshipEC-1 / Hungary / General degradation(?) fishing / TP, TN, COD and lakeuse are combined in a multimetric stressor (MAS) / R2=0,42
p<0,01
Romania / General degradation(?) fishing / TP, TN, COD and lakeuse are combined in a multimetric stressor (MAS) / R2=0,33
p<0,01
Assessment concept
The assessment concept is similar. The biomass metric is identical.
Method / Assessment conceptHU / Epilimnion is sampled.
Phytoplankton biomass is incorporated into the index. In the composition metric the emphasis is on the relative abundance of the impacted taxa. The majority of the impacted taxa are cyanobacteria.
RO / Epilimnion is sampled.
Phytoplankton biomass is incorporated into the index. In the composition metric the emphasis is on the diversity and on the relative abundance of the cyanobacteria.
4. Description IC dataset and data acceptance criteria
Data collection within the GIG.
DatasetSize of common dataset: total number of sites / 26 sites 55 lakeyear
Number of Member States / 2
Repackage/disaggregation of samples/WB results?
Gradient of ecological quality / Fully covered
Coverage per ecological quality class / High: number of sites: 13; Lake-year: 22
Good: number of sites:14; Lake-year: 21
Moderate: number of sites: 5; Lake-year: 6
Poor: number of sites:1; Lake-year:1
Bad: number of sites: 3; Lake-year: 4
Member State / Number of sites or samples or data values
Biological data / Physico- chemical data / Pressure data
Hungary / 211 / 211 / 211
Romania / 12 / 12 / 12
Data acceptance criteria used for the data quality control and describe the data acceptance checking process and results
Data acceptance criteria / Data acceptance checkingData requirements (obligatory and optional) / HU: data from the vegetation period
RO: data from the vegetation period
The sampling and analytical methodology / HU: sampling of the euphotic layer, determination of the absolute and relative abundance of taxa by inverted microscope.
RO: sampling of the euphotic layer, determination of the absolute and relative abundance of taxa by inverted microscope
Level of taxonomic precision required and taxalists with codes / Taxa have to be identified to species level
The minimum number of sites / samples per intercalibration type / One type can be intercalibrated. The database contains 55 lake-year data
Sufficient covering of all relevant quality classes per type / Data cover a wide range of stressors
Other aspects where applicable / In order to have data in the heavily impacted lake category, data for lakes that smaller than 50 ha had also to be used
5. Common benchmarkig
There are no reference sites in the EC-1 lake-type, therefore alternative benchmarking was used
Common approach for setting alternative benchmark conditions
During the benchmarking a multistep process was applied. The main steps of this process were the followings:
· Compilation of a common database in which morphometric features of the lakes, biological, chemical data and various pressures (land-use, lake-use, TP, TN, COD )are collected.
· Experienced staff of the regional water authorities was asked to propose lakes of “good quality” on basis of best professional judgement.
· Reference criteria used by EU countries and specified in the most recent Intercalibration Guidance (EC 2010) were applied to these lakes. We investigated, which are those criteria that are common for all the proposed “candidate lakes”. These criteria are the so-called alternative benchmarking criteria for the EC-1 lakes.
· The benchmarking criteria were applied to the whole lake population. The lakes that fulfilled all the benchmarking criteria were selected as alternative benchmark lakes.
· The rest of the lake population was divided into an impacted, and heavily impacted lake population.
Description of criteria for screening of alternative benchmark sites
· absence of major point sources in catchment
· no (or insignificant) artificial modifications of the shore line
· complete zonation of the macrophytes in the littoral zone
· no mass recreation (camping, swimming, rowing
· low/moderate fishing (Fish stock <50kg/ha)
(The impact of land-use has also been investigated but it showed no relationship with the metrics)
Alternative benchmark sites for each Member State in each common IC type