Environmental campaigners have called for supertrawlers to be banned after dead porpoises washed up on Sussex shores.

The aquatic mammals, thought to be killed by large fishing boats in the Channel, washed up in Pagham on November 29 and in Worthing a day later, with another spotted on the Isle of Wight.

Campaigners claim the supertrawlers are to blame for dozens of dolphins being killed on the coastline as a result of unsustainable fishing practices.

Clive Funnell, of Littlehampton Environment and Places, said: “In the last few weeks the supertrawlers keep disappearing and coming back.

A dead dolphin found near Pagham in Bognor A dead dolphin found near Pagham in Bognor (Image: Littlehampton Environment and Places)

He added: “Yes, dolphins die but it is not because of rough water – they are used to that, it’s their home.

“Supertrawlers are a completely different ball game. We are trying to save and protect them.”

Supertrawlers use nets up to a kilometre long and 200m wide to catch fish such as mackerel and herring and can catch thousands of tonnes of fish per trip, according to the Sussex Dolphin Project.

Due to their size, the supertrawlers also catch large quantities of non-target animals, called bycatch.

The bycatch can include dolphins and porpoises as well as sharks and seals.

Clive told The Argus that supertrawlers had the ability to catch entire pods of dolphins in their fishing process due to their size and capacity.

Two of the boats, dubbed Dirk Dirk and Afrika, have been spotted fishing off the Brighton coast in recent months.

Supertrawler Dirk Dirk off the coast of Brighton last yearSupertrawler Dirk Dirk off the coast of Brighton last year (Image: Sussex Dolphin Project)

The two Dutch boats measure 95m and 126m long respectively.

The vessels have now both left the area.

Clive and Sussex Dolphin Project are calling for a ban on supertrawlers in British waters.

Lloyd Gofton, director of Sussex Dolphin Project, said: “Supertrawlers are a major concern as they remove vital prey species from the marine ecosystem, but also directly cause bycatch issues.

“These prey species form the backbone of the marine food web, and the scale of biomass removed from the ocean puts huge pressure on the wider marine ecosystem, and our local sustainable fishers, with one vessel capable of catching thousands of tonnes of fish per trip.

A dead dolphin in WorthingA dead dolphin in Worthing (Image: Littlehampton Environment and Places)

"In 2020, the Sussex Dolphin Project first noticed a disturbing correlation between the presence of supertrawlers in Sussex, and an increase in dead dolphins washing up on our beaches.

"Since then, we have been monitoring supertrawler activity and working to raise awareness of these colossal factory trawlers and the impact they have on our dolphins and the local marine ecosystem.”

A petition set up by the World Cetecean Alliance calling for supertrawlers to be banned by the government currently has more than 137,000 signatures.

Sussex Dolphin Project is also calling for mandatory remote monitoring of the supertrawlers to hold the vessels accounting for their fishing practices.