Today we celebrate the international day of the harbour porpoise. It is a marine mammal, the only whale inhabiting the waters of the Baltic Sea. Along with the long-tailed duck, it is one of the key species analysed during environmental impact assessment and offshore wind farm design in Poland.

In 2002, the Agreement on the Conservation of Small Cetaceans in the Baltic, North East Atlantic, Irish and North Seas (UNEP/ASCOBANS) declared the third Sunday in May of each year as the “International Day of the Baltic Harbour Porpoise” (IDBHP) in order to raise awareness of the critical situation of the Harbour Porpoise population (Phocoena phocoena): the only species of cetacean native to the Baltic Sea.

The harbour porpoise occurs in shallow, cool, temperate to sub-arctic coastal waters in the Northern Hemisphere (e.g. in the Baltic Sea). Harbour porpoises live up to 20 years. They reach maturity at the age of 5 and grow up to 1.5-2 m and 45-65 kg of body weight.

The harbour porpoise is one of the critically endangered species in the Baltic region (HELCOM 2013). Its population has significantly decreased over the past decades. In Poland, the conservation status of the porpoise has been assessed as bad for 20 years. It is estimated that only 500 individuals live in the entire Baltic Sea.

The offshore wind energy industry is aware of this problem and responds responsibly. Monitoring and research carried out for the purpose of assessing the environmental impact of each offshore wind farm always covers the harbour porpoise. Detailed identification of the use of an analyzed part of the sea by representatives of this species allows to design layout and schedule of the construction phase in order to avoid negative impacts. Cumulative impacts with neighboring offshore wind farms are taken into account in the EIA.

Sea station named by prof. Krzysztof Skóra (Institute of Oceanography, University of Gdańsk), apart from the seal sanctuary in Hel, also pays a lot of attention to porpoises. During vacation travels, we recommend visiting the “Dom Morświna” – a micro-museum with exhibitions about the biology, history and existence of the species, as well as about the threats and methods of protection.