Phytoplankton (workpackage 4.1)
This workpackage aims at developing phytoplankton community indicators that reflect the impacts of pressures in the composition of phytoplankton determined by traditional microscopy and through analyses of pigments. Multimetric indices, which take into account species composition, size distribution and biomass parameters are tested and evaluated using data from coastal and transitional waters. Specific objectives of workpackage 4.1 are:
- to develop and validate multi-species or assemblage phytoplankton metrics,
- to evaluate the potential use of pigment data in phytoplankton assemblage metrics and
- to valuate sources of uncertainty on the determination of phytoplankton biomass and community composition due to temporal and spatial heterogeneity.
During summer 2009 field sampling was undertaken at seven sampling stations across Europe:
- Mondego Estuary (Portugal)
- Spanish Atlantic coast
- Lesina Lagoon (Italy)
- Coast of Mallorca (Spain)
- Inner Oslo Fjord (Norway)
- Helsinki Bay (Finland)
- Varna Bay (Bulgaria).
Field sampling focused on assessment of uncertainty related to sampling methods, sampling person, and small and large scale patchiness in phytoplankton. By June 2010 most samples have been analysed and preliminary results indicate differences in uncertainty related to the expert performing the analysis across the sampling locations. The most pronounced difference was found between two experts analysing samples from the Baltic Sea containing high numbers of filamentous cyanobacteria. A comprehensive analysis of the whole data set is currently being performed. Results are expected by spring 2011.
Outcome and products
A report on "Identification of type-specific phytoplankton assemblages for three ecoregions" has been finalised (Deliverable D 4.1-1) and provides an analysis of the reference conditions for phytoplankton community composition in the Baltic, the North-east Atlantic and the Mediterranean Sea. The compositions of phytoplankton communities in several water bodies in Europe that are considered to be at high ecological quality status are described. These communities are representatives of reference conditions in the respective regions. In addition, data from the non-pristine Baltic Sea are evaluated to provide a characterisation of phytoplankton under good or high ecological status. The Report also addresses the different methodologies for the study of marine phytoplankton communities. These methodologies involve a range of aspects: from the approach for selecting the most suitable data sets, to the laboratory techniques and the mathematical and statistical analyses employed.
Relevance for end users
The work on development of indicators within this workpackage is beneficial to the Geographical Intercalibration Groups and facilitates the intercalibration process for transitional and coastal waters in Europe. The estimation of uncertainty related to the biological quality elements will be helpful for realistic and sound boundary settings.