Stock of porpoises in Danish waters diminishes

The population of porpoises in Danish waters has been more than halved in seven years, according to the latest count of porpoises and other whales in European waters, Aarhus University wrote in a press release. At the last count in 2016, the porpoise population showed approximately 40,000 porpoises in inland Danish waters. The stock is now down to 14,000.
    A previous study from Aarhus University has shown that, among other things, the noise from motorboats disturbs porpoises in Danish waters, and this may contribute to the population declining. The figures showed that there are too many small motors in the coastal areas where the small whale species live. The noise prevents porpoises from using their echolocation, which is a sense they use to catch fish. In Denmark, the census is part of the Danish national monitoring of whales paid for by the Danish Environmental Protection Agency and carried out by the Danish Centre for Environment and Energy at Aarhus University. The counting is carried out from small aircraft. They fly at an altitude of 200 metres in defined routes, which together cover the counting area evenly. /ritzau/