Environmental Activists Deploy Boulder Barrier in North Sea to Block Bottom Trawling

Campaigners aboard the Greenpeace vessel Arctic Sunrise have deployed large boulders in the North Sea to create an underwater barrier designed to catch the dragnets of industrial fishing vessels. The action took place within the Southern North Sea marine protected area, which is situated along the east coast of England from north of Dogger Bank to the strait of Dover.

According to Greenpeace UK, the newly established boulder barrier has effectively closed 116 square kilometres, or approximately 45 square miles, of the protected zone to bottom trawling. The organisation stated that the Arctic Sunrise will patrol the area over the coming days to discourage other forms of industrial fishing, while activists have designated the site as an ocean park.

The Southern North Sea area is noted for supporting nearly 20% of the UK North Sea population of harbour porpoises and is intended to protect these species by maintaining prey availability. However, Greenpeace highlighted that most of the zone currently lacks fishing restrictions, with bottom trawlers logging over 37,200 fishing hours there in 2025.

Will McCallum, co-executive director of Greenpeace UK, stated that industrial ships strip the sea of fish and kill wildlife including porpoises, sharks and seabirds. McCallum noted that the group announced in June that it would take direct action if the government failed to act.

Labour MP and former climate minister Kerry McCarthy, who is a member of the all-party parliamentary group for the ocean, added her name to one of the boulders. McCarthy stated that industrialised fishing causes destructive impacts on the marine environment while less than 1% of UK seas are protected from it, calling for a ban on bottom trawling and properly protected ocean sanctuaries.

Greenpeace reported that a cumulative 55,600 square kilometres of marine protected area seabeds were affected by bottom trawlers and dredgers in 2025. The UK government has been contacted for comment regarding the activists' actions.