“Placing a clear limit on the levels of dolphins and porpoises being lost in fishing gear could play an important role in guaranteeing a recovery of these charismatic and intelligent marine mammals in European waters,” UNEP Executive Director Klaus Toepfer said in a statement on Saturday. The agency reports that members of an international conservation treaty – the Agreement on Small Cetaceans of the Baltic and North Seas (ASCOBANS) – will press the European Commission to restrict the level of marine mammals that die after becoming entangled in nets to 1.7 per cent of their populations as a first step in improving their conservation. ASCOBANS hopes that these “by-catch” limits will be taken up when the Commission undertakes a review of its Common Fisheries Policy, set to be concluded in December 2002. “Studies indicate that in some parts of the North Sea and adjacent waters, such as the Celtic Sea, 6 per cent of small cetaceans are dying after becoming entangled in fishing nets,” Mr. Toepfer said. “This may amount to more than 2,000 harbour porpoises annually in the Celtic Sea. Scientists advise that this level of by-catch is unsustainable and threatens to undermine conservation efforts.” Mark Tasker, the chair of ASCOBANS, has noted that technologies such as “pingers” are available to help fishermen reduce the level of by-catch. Pingers are small devices attached to nets which emit sounds designed to warn marine animals of imminent danger. According to UNEP, tests in British and Danish waters indicate that the by-catch of small cetaceans can be cut by more than 90 per cent when pingers are used.