Good news for the Baltic Sea's only whale

27 May, 2021
Updated 11 November, 2022

The Swedish Museum of Natural History has released a new report showing that the porpoise population in the Baltic Sea may be recovering. The porpoise, the only whale in the Baltic Sea, is critically endangered and today only 500 individuals remain.

Previously, the porpoise has been mapped through the national monitoring program, but since 2017, the Swedish Museum of Natural History has placed twelve underwater microphones in different places in the Baltic Sea to get a better overview of the whale. The porpoise uses sound, so-called echolocation, to navigate, hunt and communicate in the water. The researchers have had a greater impact on their tracking than before, which could mean that the porpoise population has increased.

“The population is still very small and the increase is far from what you would expect in a healthy population without threats, but it is still a fantastically gratifying sign,” says Julia Carlström, researcher at the Swedish Museum of Natural History.

Despite the fact that there are plenty of porpoises on the west coast, the Baltic Sea’s population is its own genetic variation that the researchers believe needs local protection efforts in the Baltic Sea to survive. The major threats to porpoises today are mainly that they ingest environmental toxins, become by-catch or are exposed to noise from shipping or wind power.

What has made the stock appear to have recovered, the researchers cannot say with certainty. But they have applied to investigate the species more closely through inventory and mapping, to better understand what protective measures are required to save the Baltic Sea’s only whale.

Read the full study here.

Source: Naturhistoriska riksmuseet
Photo: Martin Almqvist / TT Bild
For thousands of years there have been porpoises in the Baltic Sea – a shy dolphin-like whale. But due to environmental toxins and fishing, their numbers have declined sharply since the mid-20th century. The harbour porpoise population in the Baltic Sea is currently classified as critically endangered. The question is, is it too late to save the porpoise?…
Reportage: Martin Widman and Björn Hagberg
Header image: Martin Almqvist
Porpoise video: Jens Peder Jeppesen, Öresundsarkivet
Header image: Martin Almqvist

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