Comparison of assessment methods across water categories (workpackage 6.3)
Different taxonomic groups respond differently to human induced stress, and this information can be used to design robust monitoring programmes. Indeed, the finding that different BQEs (organism groups) respond differently to stress is one of the cornerstones of the European Water Framework Directive.
However, not only different taxonomic groups but also the different habitats within systems (e.g., pelagic versus benthic habitat in lakes, riffles vs. pools in rivers, seagrass beds vs. non-vegetated beds in coastal waters) and different systems (lakes, streams and transitional/coastal) may "respond" differently to different stressors. In workpackage 6.3 we test this conjecture by comparing the response signatures of different BQEs in different water categories and habitats to degradation.
Moreover, as aquatic systems are not isolated, but interconnected with both terrestrial-aquatic and aquatic-aquatic linkages, a second objective is to study how different systems are connected in space and time, and the importance of this connectively for explaining local species composition (e.g. using meta-community theory).
The data for testing the response of different taxonomic groups to different stressors has been collated by the different workpackages in Modules 3 and 4. Species by sites data matrices (both presence/absence and abundance) combined with spatial coordinates, water chemistry and land use/cover will be analyzed using ordination and regression techniques.
Relevance for end-users
Knowledge of stress-response relationships of different taxonomic groups in different habitats and water categories will be used to develop guidance on selecting the "best" indicator (i.e. high sensitivity, but low uncertainty with respect to data generation and analysis) for the pressure of interest. This information should result in more robust and cost-effective monitoring programmes.