1. Population growth rate, abundance and distribution of marine mammals Population growth rate. Population growth rate should be positive until hampered by natural limitations. Deviations during the phase of exponential increase are indicative of that the population is reaching its carrying capacity or is affected by human impacts. Near the carrying capacity, the population fluctuates but a continuous decline indicates that the population is not in good environmental status (GES). Abundance. Population abundances of the marine mammals are informative indicators of the state of the populations. Distribution. The abundance of populations in different parts of the Baltic Sea gives an indication of the distribution of the population.

2. Population growth rate, abundance and distribution of marine mammals Stage of developmentIndicator type CoreState Primary importanceSecondary importance BSAP Segment and Objective Biodiversity - Healthy wildlife Biodiversity: - Thriving and balanced communities of plants and animals -Viable populations of species Hazardous Substances: - Concentrations of hazardous substances close to natural levels MSFD Descriptors and Criteria D1. Biodiversity D1.3. Population condition D1. Biodiversity D1.1 Species distribution (range, pattern, covered area) D1.2 Population size (abundance, biomass) D4. Food webs D4.1. Productivity of key species or trophic groups D4.3 Abundance/distribution of key trophic groups/species D8. Contaminants D8.2. Effects of contaminants Other relevant legislation: (WFD - Chemical quality, Habitat directive Legislative linkage:

3. Population growth rate, abundance and distribution of marine mammals Concept/ design Coordinated monitoringAssessment Research needs for operationalization (in relation to needs stated under the coordinated monitoring and assessment columns) Data arrangements Monitoring strategy (method, frequency, spatial resolution) in relation to relevant indicator parametersTechnical guidelinesGeographic scale Assessment method GES / assessment criteria (currently all GES are provisional) A ) in place B) under development C ) not available, what needs - action level? A ) monitoring in place B ) monitoring needs revision C ) monitoring not available, what needs - action level? A ) in place B ) needs revision, what needs doing C ) not available, what needs - action level? HELCOM assessment units: A ) identified B) Identified not described C) not identified, what needs - action level? A ) available and described B ) available not described C ) not available, what needs - action level? A ) proposed and described B ) proposed but needs more supporting data C ) not available, what needs - action level? A ) in place B ) needs revision, what needs doing C ) not available, what needs - action level? B for seals but not for harbour porpoises B for seals C for harbour porpoises B for grey and seals but B for ringed seals in Estonia C for harbour porpoises. A for all speciesA for grey and harbour seals B for ringed seals in Estonia and GOF C for harbour porpoises. B for seals C forharbour porpoises B for seals but not for harbour porpoises A for seals C for harbour porpoises A for seals C for harbour porpoises A for grey and seals but B for ringed seals in Estonia C for harbour porpoises. A for all speciesA for grey and seals but B for ringed seals in Estonia C for harbour porpoises. A for seals C for harbour porpoises Ringed seals in Estonia: Investigate alternative methods since counts on ice are not applicable in a majority of years. Harbour porpoise: Investigate alternative methods A for seals C for harbour porpoises Example Fill in for current situation (action level = who needs to complete the task)

4. Population growth rate, abundance and distribution of marine mammals GES: At the moment all the populations are assessed against their intrinsic growth rate during exponential growth: Grey seals and ringed seals: 10 % intrinsic growth rate. Harbour seals: 12 % intrinsic growth rate. Harbour porpoise: 4 % intrinsic growth rate. At Carrying capacity: No decline exceeding 5% over a period of six years No decline in distribution People involved: Tero Härkönen, Karin Hårding, Olle Karlsson, Anders Galatius, Markus Ahola.

5. Population growth rate, abundance and distribution of marine mammals HELCOM Assessment Unit Level: 1 The indicator is applicable in: All of the Baltic for grey seals, the Bothnian Bay, the Gulf of Finland and the Estonian coastal waters for ringed seals. Southern Baltic and the Kattegat for Harbour seals. Currently data is available : Available for all seal species, but not for harbour porpoises

6. Population growth rate, abundance and distribution of marine mammals List of issues that still need to be solved for the indicator Describe what is hindering solving the issue Ringed seal abundance and distribution in the Gulf of Finland and the Gulf of Riga Ice situation has changed such that surveys during moult on ice are not possible during most winters. Need to investigate if counts of seals hauled out during lautumn can be used instead. Abundance of harbour porpoises Survey method not applicable when abundance is very low. Need for developing other e.g. acoustic methods.

7. Population growth rate, abundance and distribution of marine mammals -Temporal trends in weaning weights of grey seal pups. --Autumn weights of pups of the year in harbour seals FUTURE INDICATORS