Measures to stop dolphins and porpoises dying after being caught in fishermen's nets are being examined by MPs on Wednesday.
Dolphins drown after being caught in fishermen's nets
Hundreds of carcasses have already been washed up on South West beaches so far this year.
But the peak season for dolphins and porpoises washing up on the South West coast is approaching, with at least six found dead in Devon last week.
They drown after being caught in fishermen's nets, and a cross-party select committee of MPs is investigating how to stop that.
The committee will hear on Wednesday from Devon campaigner Linda Hingley, of Brixham Seawatch, which monitors dolphin deaths.
She wants a ban on pair trawling until measures are introduced which stop dolphins being caught.
Pair trawling involves two boats dragging a huge net between them.
Fisheries Minister and Exeter MP Ben Bradshaw will also present his proposals for tackling the problem to the committee.
He is suggesting escape hatches in nets, but Ms Hingley says his plans will not work.
She said: "People don't realise that these trawl nets are so big you could park seven jumbo jets inside them.
"The biggest problem with them is the dolphins swim into these trawls while feeding on fish already in them and they don't realise they are caught."
The Cornwall Wildlife Trust launched a hotline last month so people could contact them if they found a dolphin washed up on a beach.
They hope the hotline will allow experts to identify the cause of death quickly and speed up measures to reduce the number of fatalities.