Scientists say 61% of deaths since 1990 have been caused by fishing
Trials have been taking place off the Cornish coast to test devices which could help prevent dolphins and porpoises being caught in fishing nets.
Marine conservationists hope the hi-tech sonic device, known as a pinger, will stop the creatures' decline.
The teams behind the equipment are hoping to get funding to carry out further tests.
The devices emit a signal which is designed to drive the creatures clear of the fishing nets.
Last month scientists from the University of Exeter's Cornwall Campus and Cornwall Wildlife Trust published a report, which said industrial fishing was largely to blame for the increase in the number of dead whales, dolphins and porpoises being washed up on Cornish beaches.
Their research showed 61% of deaths since 1990 were confirmed as being caused by fishing, with the creatures accidentally caught up in trawlers' nets as "bycatch".
Joana Doyle, marine conservation officer for Cornwall Wildlife Trust, said steps had to be taken to safeguard the future of the cetaceans.
The trust would like a network of marine conservation zones established on the coast.
It is also in favour of an EU-wide ban on pair trawling for seabass, which involves two vessels working together dragging a huge net between them.
The Department for Food and Rural Affairs (Defra) has said studies of the effectiveness, costs and availability of pingers indicated the devices need more development.
But it said the government would continue to work with the industry to explore methods to assist in species protection, including the creation of a suitable pinger.