Cornwall Wildlife Trust says it has has found a potential solution to the biggest threat facing Cornwall’s dolphins and porpoises – getting tangled in fishing nets.

Known as ‘pingers’, these devices are fitted to the nets and emit a regular sonic noise to highlight the presence of a net to the animals, reducing their chances of becoming entangled.

The charity says that in the past, there have been problems associated with the practicalities and safety of using pingers when previously trialled on larger offshore fishing vessels.

This also raised the question as to whether pingers would be practical on smaller vessels, which make up a large proportion of our Cornish inshore static net fishing fleet.

To tackle this problem, Cornwall Wildlife Trust, which has 14,000 members and 90 Business Members, has been working in partnership with Cornish inshore fishermen to trial a suitable pinger that will stop dolphins and porpoises getting caught in nets, without causing major practical problems for usual fishing activity.

The Trust’s pinger trial used hydrophones to monitor porpoise and dolphin activity around nets with and without pingers. The cahrity says the results were positive and showed a 48 per cent reduction in harbour porpoise activity around nets with pingers.

Ruth Williams, marine conservation manager for Cornwall Wildlife Trust said: “We are delighted that the trials proved such a success, not only in testing what could be an essential tool in protecting our enigmatic and precious inshore dolphins and porpoises, but also in building good relationships with the fishing industry in this county.

"The fact that this work has been recognised by the scientific community and published is an additional feather in our cap and we hope we can further progress this vital area of work to help protect our dolphins for the future.”

A spokesman for the trust said: "The feedback from the skippers involved and the trust’s investigation have concluded that there are no significant practical problems using pingers on the fishing vessels.

"However, the initial cost and short battery life of the pingers are an issue, but the trust is dedicated to continuing this research to find a suitable commercial pinger that can be used effectively on all inshore fishing boats."

Ruth Williams added: "Cornwall Wildlife Trust will continue to iron out the small problems we have encountered and persevere to find the most suitable pinger for the industry and our dolphins.’ The report is available to download of Cornwall Wildlife Trust’s Living Seas pages www.cornwallwildlifetrust.org.uk/livingseas.