Three populations of the harbour porpoise (Phocoena phocoena) inhabit the waters around Germany: while recent estimates (SCANS aerial surveys) suggest that the North Sea and North Atlantic are populated by approximately 380,000 animals, there are around 15,000 harbour porpoises in the western Baltic Sea between the Skagerrak and Fehmarn.
However, fewer than 450 individuals of the Baltic Proper harbour porpoise in the east are believed to remain. The pressures on these sensitive cetaceans are too immense: fisheries and bycatch, derelict fishing gear (ghost nets), chemical pollutants, and prey depletion.
A female harbour porpoise requires approximately 5 to 6 years to reach sexual maturity, but the average life expectancy in the eastern Baltic Sea is currently just 3.5 years. Consequently, under current conditions, it is virtually impossible for the population to produce offspring.
It is to be hoped that effective measures will finally be implemented to conserve this threatened population. Ultimately, the harbour porpoise is designated as a protected species under EU law.
Sources:
- Gilles et al., 2023: Estimates of cetacean abundance in European Atlantic waters in summer 2022 from the SCANS-IV aerial and shipboard surveys. https://www.tiho-hannover.de/en/clinics-institutes/institutes/institute-of-terrestrial-and-aquatic-wildlife-research-itaw/scans-iv-survey
- Owen et al., 2024: A negative trend in abundance and an exceeded mortality limit call for conservation action for the Vulnerable Belt Sea harbour porpoise population. https://doi.org/10.3389/fmars.2024.1289808
- Koschinski et al., 2025: Current species protection does not serve its porpoise—Knowledge gaps on the impact of pressures on the Critically Endangered Baltic Proper harbour porpoise population, and future recommendations for its protection. https://doi.org/10.1002/ece3.70156
- Scans IV Survey, https://www.tiho-hannover.de/en/clinics-institutes/institutes/institute-of-terrestrial-and-aquatic-wildlife-research-itaw/scans-iv-survey
