A study by French researchers has shown that only 8 percent of the animals killed as bycatch were actually detected. Harald Benke, the head of the German Marine Museum said the results are alarming.

During a congress of European whale researchers in Cadiz, Spain, it was discussed that bycatch is apparently a bigger problem than previously assumed and similar investigations should be carried out for the endangered Baltic Sea Harbour Porpoise. Bycatch figures often include a number of unreported cases. The researchers marked 100 dead dolphins and porpoises caught in fishnets along the French coast and returned them to the Atlantic Ocean from the fishing vessels, only 8 per cent of them were later found on the coast.

The scientists also say that porpoises in the Baltic Sea are also threatened by the fishing industry. Researchers along the German coast have found an increasing number of dead animals in recent years with the figures rising anually.

In all countries which report important examination results, bycatch was the leading cause of death of the examined animals and the latest French study shows that only a fraction of the animals which die in this manner are reported.