Danish scientific appraisal of HELCOM’s and OSPAR’s indicators in relation to the monitoring programme under the marine strategy framework directive:status 2020

The road map includes the following indicators:Page number: D1 Biodiversity D1 Biodiversity (Marine mammals) Abundance and Distribution of Cetaceans M4-B Abundance and distribution of harbour porpoises (candidate) Key site density of harbour porpoises (candidate) Nutritional status of marine mammals Reproductive status of seals Seal pup weight at weaning Marine Mammal Health D1 Biodiversity (Birds) Number of drowned waterbirds in fishing gear / Marine bird bycatch Abundance of waterbirds in the breeding season / Marine bird abundance (breeding) Abundance of waterbirds in the wintering season / Marine bird abundance (non-breeding) Distribution marine birds/seabirds Non-native/invasive mammal presence on island seabird colonies Marine bird habitat disturbance Waterbird breeding success/failure D1C6 Pelagic habitats Diatom / Dinoflagellate index Seasonal succession of dominating phytoplankton groups Phytoplankton community composition as a food web indicator Phytoplankton species assemblage clusters based on environmental factors Phytoplankton taxonomic diversity Zooplankton mean size and total stock (MSTS) Changes in Phytoplankton and Zooplankton Communities Changes in Plankton Diversity Changes of plankton functional types (life form) index Ratio Changes in Phytoplankton Biomass and zooplankton Abundance Chemical ocean acidification indicator Production of phytoplankton [Candidate] D2 Non-indigenous species Trends in arrival of new non-indigenous species (D2C1) D4 Food webs Changes of plankton functional types (life form) index Ratio FW5 Biomass, species composition and spatial distribution of zooplankton FW6 Biomass trophic Spectrum (BTS) FW8 Ecological network analysis (Foodwebs FW9) D5 Eutrophication Nutrient concentrations Chlorophyll concentration Water clarity Shallow water bottom oxygen Phytoplankton spring bloom intensity based on chlorophyll a Biomass ratio of opportunistic and perennial macroalgae D5C6 (eutrophication) D6 Seafloor integrity Condition of the Benthic habitat D6C4 -HELCOM Population structure of long lived macrofauna communities (under D6C3) State of the soft-bottom macrofauna community (Eutrophication D5C8) Condition of the benthic habitat-Chronic effect on bivalves (BH5) Condition of the benthic Habitat communities BH2 Habitat loss BH4-OSPAR Cumulative impact on benthic biotopes State of the hard bottom communities State of soft-bottom macrofauna communities D6C5 D10 Marine litter Beach litter -Amounts and composition on reference beaches Microlitter in water column and sediments D11 Underwater Noise Continuous low frequency anthropogenic sound (HELCOM) Ambient noise (OSPAR) Distribution in time and space of loud low-and midfrequency impulsive sounds (HELCOM) Distribution of Reported Impulsive Sounds (OSPAR) Impulsive noise impacts (OSPAR)harbour porpoise, a 30% decline over 3 generations corresponds to an annual decline of 1.77% or just over 9% over the 6 year reporting cycle". Description of challenges and reservations:Historical data on abundance and distribution are lacking, so it is impossible to base the favourable reference value on historic abundances.Thus the indicators must focus on current trends and as such AU supports the suggested threshold as described above.The possibility to detect trends should be improved by increasing the frequency of large-scale surveys to every 6 th year.Furthermore, to date, large-scale surveys have been undertaken during summer, resulting in a lack of seasonal information at the large scale.The abundance estimates should be produced on a regular 6-year interval in order to provide data for the EU reporting periods. Suggestions for solutions and process forward