Achieving good and preventing deterioration in relation to indicator 4.3.1. (trends in numbers of functionally important selected groups/species: Biomass of Mesozoplankton)

To obtain data to assess the relevance of the indicators for the description of criteria 4.1 and 4.2 in cooperation with neighbouring countries.

Obtain data to upgrade the assessment to criterion 4.3 (abundance/distribution of key trophic groups/species) in cooperation with neighbouring countries.

The relevant missing metrics must be tested and harmonised at sub-regional level.

The development and harmonisation of methods to assess the situation on the basis of quality descriptors for food webs (D4), including the determination of the value relevant for assessment.