The Dutch parliament wants to see measures in place by the summer to ensure that no more porpoises end up in fishing nets. The use of gillnets in particular has to be controlled. But this will be ‘a complicated story’, says Mardik Leopold of Wageningen Imares.
Last winter several dozen mutilated porpoises were washed up on the North Sea coast. The Public Prosecution Service was considering launching a criminal investigation. But this was abandoned last week after tests by the Dutch Forensic Institute (NFI), which revealed that the porpoises were dead before they were mutilated. Their injuries were thought to have been caused by ships’ rudders.
Imares experts think this theory is nonsense. Leopold and his colleague Bram Couperus are convinced that the porpoises were the victims of bycatch by fishing boats – although there is no suggestion that this was deliberate.
A total ban on gillnet fishing is not a solution, thinks Leopold. ‘That would be the end of the fisheries.’ He is much more in favour of looking for specific solutions for particular times and places. ‘We know when it happens: in midwinter, from December to March, when masses of porpoises gather off the coast and are washed ashore, dead.’