Observation of the critically endangered Baltic Sea harbour porpoise starts again

Press release 2016-06-21 at 13:34

Early summer is a good time to observe harbour porpoises in the Baltic Sea waters. Harbour porpoise is the only species of cetaceans in the Baltic Sea, and it is critically endangered. The population in the main basin of the Baltic Sea is estimated at about 500 specimens. The estimate is based on monitoring conducted in the international SAMBAH project, where an underwater acoustic monitoring network was placed in the Baltic Sea. Data from observations by citizens is a valuable addition to the research and protection of harbour porpoises.

The campaign is conducted by the Turku University of Applied Sciences, WWF Finland, Natural Resources Institute Finland, Finnish Environment Institute and Ministry of the Environment. The aim of the campaign is to have more information on the occurrence of porpoises and disseminate information on the only cetacean species in the Baltic Sea. The Agreement on the Conservation of Small Cetaceans ASCOBANS and the Habitat Directive by EU obliges Finland to organise the monitoring of harbour porpoises and to gather information and report on them.

It is estimated that in the early 20th century there were still thousands of harbour porpoises in the Baltic Sea. The population suffered from the extremely cold winters in the 1940s when the whole of the Baltic Sea was covered with ice, and it never recovered from this. Today the main threat to harbour porpoise is being caught as bycatch in fishing. Other reasons for the population decline include environmental toxins, underwater noise and other disturbance caused by human activity. Harbour porpoises are likely to no longer breed in the Finnish waters.

In 2011–2014 there were 14 verified observations of harbour porpoises made by the acoustic monitoring in the territorial waters of Finland.  Most of these were in the open sea area to the south of the Åland Islands and the Archipelago Sea. All of the acoustic observations were made between December and May, while the visual ones were made during the summer.

Since 2001 the Ministry of the Environment has announced an annual campaign where private citizens are asked to report observations of harbour porpoises in the marine areas of Finland. By 2015 a total of 63 observations concerning 113 specimens had been reported.

How to identify a harbour porpoise?

Harbour porpoise can be identified by its low and triangular dorsal fin. They are small and roundish in shape and their visit to the surface is a rolling twirl. The back and fins are dark grey, the sides and belly are lighter in colour. Usually the head of a harbour porpoise is not above water when it is swimming, and it hardly ever jumps or comes close to vessels. Harbour porpoise is about 1.5 metres long and it weighs 50–60 kilos. They usually swim along the coast and in shallow sea areas.

Observations can be reported by using the form available on the website of the Ministry of the Environment. To make sure that the species identification is correct, a photograph and a description of the colour, shape, size and behaviour of the animal can be attached. Unharmed harbour porpoises caught in a net must always be released and seals and harbour porpoises caught as bycatches must be reported to the Natural Resources Institute Finland. 


Penina Blankett, Ministerial Adviser, Ministry of the Environment, firstname.lastname@ym.fi, tel. +358 295 250 058

Report an observation by phone:

Olli Loisa, Turku University of Applied Sciences, tel. +358 50 598 5743

Penina Blankett, Ministry of the Environment, tel. +358 295 250 058

Report a porpoise found dead:

Finnish Food Safety Authority EVIRA, tel. +358 295 0400 (switch board)