Where You Fish Matters: Bottom Trawling, Paper Parks, and the Reefs England Finally Protected

About 100 kilometres off Cornwall, Haig Fras rises from the seabed as a granite reef covered in jewel anemones and cup corals. It had been a protected area for years, and heavy fishing gear could still legally drag across it. In March 2024, England closed that gap. The story of how that happened says a lot about what protection really means, and where trawling belongs.

The footage everyone remembers

If you saw the Ocean documentary narrated by Sir David Attenborough, you remember the scene. Cameras mounted on a trawl net showed a thriving reef, full of anemones, invertebrates and fish, flattened in seconds inside a protected area. I watched it with my daughter, who studies wildlife biology, and the theatre went quiet. The film’s message was clear: ban it everywhere. It also leaves viewers wondering whether every piece of cod or shrimp they’ve eaten came from a bulldozed seafloor.

Two kinds of trawls

A trawl is a net pulled through the water. Midwater trawls move through open water and never touch the bottom. Bottom trawls drag along the seafloor over sponges, corals, seagrass and reefs, scraping away whatever lives in the path of the net and leaving visible scars. On a living reef, that’s like clearing a forest to catch rabbits.

The context that usually gets left out

Bottom trawling provides about a quarter of the world’s wild-caught seafood, roughly 19 million tonnes a year. Much of it comes from sand and mud bottoms, which recover relatively quickly. A 2018 study in PNAS mapped trawling across 24 regions and found that 14% of the seafloor studied was trawled, ranging from 0.4% off southern Chile to more than 80% of the Adriatic. Trawling also happens in the same places year after year, and regions where less than 10% of the seafloor was trawled almost always had sustainably fished stocks. That’s why some bottom trawl fisheries hold Marine Stewardship Council certification. The useful questions are where, how much, and what lives there.

Paper parks

The same year, a team from Dalhousie University and GEOMAR examined 727 marine protected areas across the European Union. Commercial trawling occurred in 59% of them, and trawling was on average 38% more intense inside the protected areas than in nearby unprotected water. In the most heavily trawled areas, sharks, skates and rays had declined by 69%. Co-author Boris Worm warned that elevated industrial use inside protected areas means we aren’t getting the conservation outcomes we need.

We call these paper parks: boundaries drawn on a map with the same extractive activity continuing inside them. It happens worldwide. MPAs get announced with fanfare and left without rules, enforcement or funding, and some are drawn where the species they were meant to protect don’t even live.

What a working MPA looks like

When MPAs are done well, the results are striking. A global review found fish biomass about 570% higher in no-take reserves than in unprotected areas, a figure the authors corrected downward in 2025 from an earlier estimate. A study of 87 MPAs worldwide identified five features that make the difference: no fishing, strong enforcement, more than 10 years old, larger than 100 square kilometres, and isolated by deep water or sand. MPAs with four or five of those features had five times more large fish biomass and 14 times more shark biomass than fished areas. Most of the MPAs in that study had only one or two.

MPAs have limits. They can’t stop warming water, acidification, plastic pollution or an oil spill drifting in from outside. They’re a powerful tool with a specific job, and they need good management to do it.

How England protected its reefs

England has dozens of offshore MPAs, and for years many allowed bottom-towed gear across the very habitats they were created to protect. In June 2022, the Marine Management Organisation brought in its first byelaws banning that gear in four offshore sites, including Dogger Bank and The Canyons. In 2023 it ran a public consultation on going further, open to fishers, scientists, conservation groups and ordinary citizens. On 22 March 2024, a new byelaw banned bottom-towed gear over sensitive reef habitats in 13 more MPAs, covering about 4,000 square kilometres, including Haig Fras, Cape Bank and Goodwin Sands.

This is what matching the rules to the habitat looks like. Trawling continues over sand and mud elsewhere and stays off the reefs that would take decades to recover.

The same logic applies to fish farms

In 2022, aquaculture produced 51% of the world’s aquatic animals for the first time, about 94 million tonnes. If you eat shrimp or salmon, you’ve almost certainly eaten farmed seafood. Like trawling, farming depends on how and where it’s done: what the fish are fed, how waste and disease are handled, and whether farmed fish escape. Look for the Aquaculture Stewardship Council (ASC) label, or Best Aquaculture Practices (BAP) as a less strict option, and check guides like Seafood Watch and Ocean Wise. Producers who do it right say so loudly because it lets them charge more. Vague packaging is usually a sign.

What you can do

The next time your government proposes a protected area or reviews the rules of an existing one, submit a comment during the public consultation. You don’t need to be a fisher or a marine biologist. Keep it simple: say you support the protected area and ask that the rules keep bottom trawling and other destructive gear off sensitive habitats. Most fisheries and environment agencies post consultations on their websites, so sign up for alerts or follow a group like Oceana that tracks them. Rules get written in consultations, and consultations count comments.

Today, no chain has crossed Haig Fras since 2024. Protect the right places, write the right rules, and the seafloor can grow back.

Takeaways

• Bottom trawling’s impact depends on the habitat. Sand and mud recover faster than reefs and sponge beds.
• Low trawling footprints line up with sustainably fished stocks.
• Many MPAs are paper parks, with trawling more intense inside them than outside.
• Effective MPAs share five features: no-take, enforced, old, large and isolated.
• England’s 2024 byelaw protected reefs in 13 more offshore MPAs through a public process.
• For farmed seafood, look for ASC or BAP and check seafood guide ratings.
• Your consultation comment helps decide whether a park is real.