The porpoise population in inner Danish waters has more than halved in the last decade, plummeting from approximately 40,000 to 14,400 individuals between 2012 and 2022. This alarming decline prompts the intergovernmental organization Helcom to consider upgrading the porpoise’s red list assessment from “vulnerable” to “endangered.”

The primary factors contributing to this decline include oxygen depletion, scarcity of cod and herring (the porpoises’ main food source), and bycatch in fishermen’s nets, which claims up to 1,000 porpoises annually.

Researchers believe that the situation can be reversed by improving porpoise habitats in areas like Lillebælt and Flensborg Fjord, through the restoration of stone reefs to create new habitats for prey like herring and cod, and by implementing speed limits and noise reduction measures for ship traffic.

The memo recommends that all vessels in the area near Naturpark Lillebælt reduce their speed to a maximum of five knots to mitigate the negative impacts of noise and disturbances from shipping.

Minister for the Environment Magnus Heunicke acknowledges the overexploitation of the marine environment and porpoise habitats, referencing a political agreement from 2024 that allocated DKK 500 million towards restoring Danish marine nature by 2030.

The government has also proposed banning bottom trawling in Lillebælt, where the porpoise population is especially concentrated. The next porpoise count in the inner Danish waters is scheduled for 2027 or 2028.