Greenpeace Creates Underwater Barrier in the North Sea to Protect Marine Life

Greenpeace activists dropped rocks into the North Sea to confuse the nets of industrial trawlers conducting bottom trawling in a protected marine area. The rocks were dropped from the Arctic Sunrise vessel, loaded in Le Havre: they form an underwater barrier around the southern protected area of the North Sea – the most trawled protected area in the UK.

The southern North Sea area is important for harbour porpoises: nearly 20% of the UK's North Sea population resides here. Despite its protected status, most of the area has no fishing restrictions: trawlers, dredgers, and other industrial vessels operate there daily. In 2025, trawlers logged over 37,200 hours of fishing in the protected area – Greenpeace UK compared this to a "bulldozer running through a valuable national park."

"Huge ships scour the sea day after day, wiping out fish and killing valuable wildlife – porpoises, sharks, and seabirds," said Will McCallum, co-executive director of Greenpeace UK. "With our ship and movement behind us, we are doing what the government is not: protecting our seas."

What the barrier achieved

According to Greenpeace UK, the barrier effectively closed off 116 sq km (about 45 sq miles) of the protected area to bottom trawling. In the coming days, Arctic Sunrise will patrol the area to deter other forms of industrial fishing. Activists declared the zone an "ocean park" in the spirit of British national parks.

The southern protected area of the North Sea stretches along the east coast of England – from north of Dogger Bank to the Dover Strait. Its purpose is to protect harbour porpoises, including by maintaining prey availability. Greenpeace UK activists believe that intensive fishing contradicts this goal. "In June, we announced: if the government doesn't take action, Greenpeace UK will move to direct action," said McCallum.