Macroinvertebrates (workpackages 4.3)
Objectives
Workpackage 4.3 is dedicated to the development of indicators for hard-bottom benthic macroinvertebrate communities to assess the impact of environmental pressures on transitional and coastal waters. Habitat-specific reference conditions provide the basis to develop ecological quality assessment systems. Possible sources of uncertainty are identified and quantified to estimate the risk of misclassification. In particular, workpackage 4.3 aims:
- to identify the pressure-response relationships of coastal and transitional benthic invertebrates based on existing data and new data obtained during the joint field sampling survey,
- to analyse the response of single and multimetric methods to pressure gradients in distinct aquatic systems (bays, lagoons, estuaries and fjords),
- to develop indicators for hard-bottom (rocky) substrate benthic macroinvertebrate communities, based upon data from a new field campaign,
- to refine numerical models linking biological and environmental aspects to define reference conditions (e.g., using multiple and logistic regression and multivariate methods),
- to define reference conditions, particularly concerning the role of single and complex habitats, in ecological status assessment of transitional waters (estuaries and lagoons) and
- to determine the risk of misclassification using different indicators and scales (sampling station, water body, etc.).
Data
An extensive field campaign including five transitional and coastal water stations across Europe (Varna Bay in Bulgaria, Lesina lagoon in Italy, Mondego estuary in Portugal; Basque coast in Spain and Oslofjord in Norway) generated additional data needed to develop new indicators and set reference conditions. Very often, sites on transitional waters are impacted by different pressures in parallel.
Outcome and products
A "Manuscript on the responses of existing indicators to different pressures" for transitional and coastal waters has been drafted to investigate the response of 21 benthic macroinvertebrate community measures (metrics) along different pressure gradients (D4.3-1). The metrics are largely consistent in their response to pressure gradient, except of some particular cases. Inconsistencies between indicator responses were mostly in transitional waters and highlight the shortcomings of the generic application of indicators irrespective of the specific estuarine or lagoonal environment. Yet, some metrics (e.g., ecological groups, diversity and richness measures) and multi-metric indices (e.g., BAT index, M-AMBI index, NQI index) were able to detect such general gradients in both transitional and coastal environments. The manuscript highlights the importance of survey design and good reference conditions for indicator development and application and has been submitted for publication (in revision).