Porpoises to be taped underwater
1st May 2004
Underwater microphones (hydrophones) are to be used in a project to detect whether endangered harbour porpoises are returning to UK coastal waters.
If successful, it could be repeated in estuaries around Britain.
Harbour porpoises - one of the world’s smallest cetaceans - were so abundant in the 1920s that they were hunted and shot.
But the population since the mid-20th century has suffered a steep decline from fishing net by-catch and pollution, and they are now rarely seen in estuaries.
The International Fund for Animal Welfare (IFAW) has estimated that about 10,000 harbour porpoises are killed each year in EC waters.
The air-breathing mammals are vulnerable to being entangled and killed in gill nets, the fine filament of which is undetectable to their sonar.
The year-long IFAW-funded project in Cornwall’s Fal estuary involves attempting to detect the presence of porpoises via the sonar "clicks" they emit to navigate and find food.