A new report from Oceana UK has found that not a single marine protected area designated to safeguard cetaceans in UK waters fully bans bottom trawling – and that the harm caused by the practice extends far beyond the seabed, cascading through entire marine ecosystems to threaten porpoises, puffins, whales and seabirds.

The report – titled Trawled and Mauled – draws together evidence of the cascading impacts bottom trawling has on species that never touch the seafloor, from harbour porpoises and humpback whales to puffins, terns and kittiwakes. The UK government’s own assessments already identify bottom trawling as a threat in 75% of the MPAs in question. 

Oceana’s report adds new and weighty evidence that partial protection is – in practice – no protection at all.

Satellite tracking data shows that the Southern North Sea Special Area of Conservation – a sanctuary designated specifically to protect harbour porpoises – was subjected to 30,936 hours of apparent bottom trawling in 2025 alone. That is the equivalent of 1,289 continuous days of destructive fishing, packed into a single year, inside an area that exists – on paper – to keep these animals safe.

By destroying seabed habitats, bottom trawling depletes populations of sandeels and other small fish that form the foundation of the food web on which whales, seabirds and other predators depend. Meanwhile, the heavy gear generates intense underwater noise as it scrapes across the seafloor, disrupting the echolocation that dolphins and porpoises rely on to hunt. Clouds of disturbed sediment reduce water clarity,negatively  impacting how seabirds such as puffins and terns hunt. Finally, the nets themselves can entangle and kill the very species the MPAs are meant to protect.

Hugo Tagholm, Executive Director of Oceana UK, said the scale of the problem raised fundamental questions about the credibility of UK marine protection. 

“Our report reveals that the deep harms caused by bottom trawling are not limited to life on the seabed. Harbour porpoises, puffins, terns and countless other animals need healthy habitats and abundant prey. The government simply cannot claim that these areas are protected while allowing destructive trawling inside them. 

“Areas designated to protect some of our most iconic species are still allowing a destructive activity that the government’s own assessments identify as a threat. This raises a serious question about the credibility of the UK’s marine protection measures and the true extent of its ambitions. The UK has promised to effectively protect 30% of the ocean by 2030, but there is a risk of bold targets being reduced to little more than blue washing. If we are serious about meeting that commitment, protection must exist in practice not just on paper.”

Professor Emma Sheehan, Professor of Marine Ecology at the University of Plymouth, added: “Bottom trawling harms seabirds and cetaceans in many ways, directly and indirectly. Animals can become trapped in fishing gear, suffering an agonising death. But many of the impacts occur through changes to the wider ecosystem. Bottom trawling ravages habitats, removes prey and generates intense underwater noise. Seabirds and cetaceans sit near the top of marine food webs. Their survival depends on healthy ocean ecosystems. Marine protected areas are designed to conserve vital ecosystems and species and allowing bottom trawling within them undermines the very purpose of their designation.”

The economic argument for protection is also gaining traction from within the fishing industry itself. According to Defra, 80% of fishers in England agree that the conservation and restoration of the marine environment is important for their job security. 

Sussex fisherman Clive Mills, who once operated his own trawler, has witnessed the destruction first hand. “I used to have my own trawler, and I’d be out there all day and night. I could see with my own eyes the damage being done. It’s not just what you land, it’s what you kill. It’s the destruction that bottom trawling does, on a massive scale. 

“If we did it on land, you would literally stop it overnight. People would be up in arms and there would be uproar. But because we can’t see it, we let it happen. We’ve just got to look at what we’re doing now. We need to change what we’re doing. We need to look it in the eye and start fishing for the future.”

The UK government has committed to a public consultation on bottom trawling management in five MPAs designated to protect seabirds and cetaceans – a commitment that has yet to produce binding action. Oceana UK’s urges that protected areas now need to fulfil their legal and ecological purpose, be entirely free of bottom trawling, not partially restricted, not subject to ongoing consultation, but fully protected.

To mark the report’s launch, Oceana UK projected footage of bottom trawling onto the white chalk cliffs of Botany Bay in Kent – cliffs that look out over an MPA designated to protect the amber-listed little tern.

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