Although they are the only cetaeceans regularly found in Swedish waters, no one knows how many porpoises there actually are.
“There could be anywhere from 10 porpoises to 3,000,” said Mats Amundin, zoologist at the Kolmården Zoo and the coordinator of a project in collaboration with the Environmental Protection Agency (Naturvårdsverket) that will try to count the number of porpoises in the Baltic Sea.
The work will be done by monitoring the porpoises’ communications system with 300 “porpoise detectors” that collect data on cetaecean sonar.
“We want to have more precise information so that we can implement the right measures to protect the population,” Amundin told newspaper Norrköpings Tidningar.
The porpoise is one of the smallest cetaecean species. It is related to whales and dolphins and is 120 to 225 centimetres long. The species is protected in Swedish waters in the North Sea and its survival is vulnerable, while in the Baltic Sea, it is classified as an acutely threatened species.