Female reproductive status of marine mammals -particular emphasis of seals

1. Female reproductive status of marine mammals -particular emphasis of seals The concept of using reproductive parameters of seals as core indicator for GES within Helcom is based on • the female reproductive status is sensitive for contaminants and starvation • top predator, highly exposed to persistent chemicals - reproductive parameters signalled for harmful effects already in the 1970s in Baltic grey and ringed seals • pregnancy rate was 9 % in the Baltic grey seals in the 1970s to mid 1980s • pathological changes are still found the reproductive tract in ringed seals • strong evidence for relationships with POPs

2. Female reproductive status in marine mammals Legislative linkage:

3. Reproductive parameters (seals) • Pregnancy rate: • measured as percent pregnant females in the pregnancy period, 6-24 years old • Birth rate: • measuredas corpora albicantia/uterine postpartum signs between the time of ovulation and implantation in 7-25 years old females • Ovulation rate: • Determined from corpus luteum (CL) in ovaries (April-June for grey and ringed seals, Harbour seals- to be determined) • Reproductive health: • measured as percent uterine pathological changes (uterine obstructions and leiomyoma) in seals older than 6 years and in any season

4. Uterus and ovaries of a grey seal female Photo: Charlotta Moraeus

5. Female reproductive status of marine mammals Beginning of CORESET II current situation (action level = who needs to complete the task)

6. Female reproductive status of marine mammals - GES • Bäcklin B-M (Sweden), Kunnasranta M and Isomursu M (Finland). Health assessment in the Baltic grey seal (Halichoerusgrypus). HELCOM Indicator Fact Sheets 2008 (Ringed seals since 2010) • In 2012 “Pregnancy rates of marine mammals” was a proposed Core Indicator for Biodiversity • In 2014 spring meeting in Stockholm (Fin+Swe) we renamed the Core indicator to “Female reproductive status of marine mammals” as we not determine only the pregnancy rate • The age interval used for the reproductive status has been modified from 4-20 year to 6-24 year (for pregnancy rate) and 7-25 years (for post partum signs) in grey and ringed seals. The age class in not yet determined for harbour seal

7. Female reproductive status of marine mammals - GES • Good environmental status is determined when the “pregnancy rate” is above a threshold level (=GES) defined by Swedish and Finnish hunted grey seals from 2008-2009 • GES is sat to the lower 95% confidence interval. GES is reached when 80 % of the females are pregnant/or show post reproductive signs (in an increasing population). The same GES boundary has been suggested for ringed seals. Whether or not similar GES limits can be suggested for harbour seals and harbour porpoises remains to be investigated • Data will mainly be presented as trends. Reproductive data will be presented in five years interval for grey seals, intervals for ringed and harbour seals are not decided yet • People involved today: Britt-Marie Bäcklin, Charlotta Moraeus, Tero Härkönen, Swedish Museum of Natural History KaarinaKauhala, Finnish Game and Fisheries Research Institute MarjaIsomursu, Finnish Food Safety Authority, EVIRA Ursula Siebert, Institute for Terrestrial and Aquatic Wildlife Research (ITAW), University of Veterinary Medicine Hannover, Foundation

8. Female reproductive status of marine mammals • HELCOM Assessment Unit Level: 2 • The indicator is applicable in: For grey seals, results are considered applicable for the whole Baltic Sea, whereas the ringed seal results may apply only to Bothnian Bay. For harbour seals data is applicable on the Swedish West coast. • Currently data is available : From the Swedish and Finnish coast of the Baltic Sea and Swedish West coast. • Missing data: Bay of Riga, Poland Germany, Denmark for seals. All areas for Harbour Porpoises

9. Female reproductive status of marine mammals