Sonic devices to deter Cornish dolphins from nets
A potential solution is being developed to protect Cornwall’s dolphins and porpoises from the continuous threat of becoming entangled in fishing nets.
Small devices, known as ‘pingers’, are fitted to the nets before emitting a regular sonic noise underwater, deterring the animals from the nets, and reducing the chance of entanglement.
The Cornwall Wildlife Trust have been testing the devices on fishing trawlers off the Cornish coast, and the results have been positive.
Using hydrophones to monitor activity in the water, the Trust saw a 48% reduction in porpoise activity around nets with ‘pingers’ attached.
Local fishermen are keen to find new technology to help them avoid accidentally entangling dolphins and porpoises in their nets.
Problems with previous ‘pingers’ have included the initial cost and short battery life of the devices, and the Trust are working on new technologies to combat this.
Jim Portus, president of the South West Fish Producers' Organisation, told This Is Cornwall:
'The trial and testing of this equipment has been around a long time, and it's about time that the technology has moved on so that there's a low-cost option that's effective and easy and safe to use.’
Aside from the common dolphins and porpoises becoming caught and drowning in nets, there is a small pod of bottlenose dolphins that have reduced in number from 18 to 6 since 1991.
Ruth Williams, Marine Conservation Manager for Cornwall Wildlife Trust, has said:
'We will continue to iron out the small problems we have encountered and perservere to find the most suitable pinger for the industry and our dolphins.’