UK Claims 38% of Its Seas are Protected. Thousands of Hours of Apparent Trawling and Dredging Suggest Otherwise

On paper, the United Kingdom is a champion of the oceans. More than 38% of UK waters are now designated as Marine Protected Areas (MPAs), a network of underwater sanctuaries to be set aside for nature to thrive. In fact, Britain has already surpassed the landmark global target of protecting 30% of the seas by 2030, an international target known as “30 by 30”.

However, these designations don’t always translate into meaningful protection.

In many British protected areas, trawling and dredging, two of the most destructive types of fishing, still happen at scale. In the past year alone, there have been tens of thousands of hours of apparent fishing inside marine protected areas, potentially destroying delicate habitats. This practice has been described by scientists and conservationists as inconsistent with the goals of marine conservation. A recent review concluded that “without systematic restrictions on damaging fishing gears, MPAs are unlikely to help reverse the ongoing declines.”

A new government consultation could change all this and bring real protection to dozens of MPAs.

The sweeping government consultation, led by the Marine Management Organisation (MMO), is in its final days. It proposes the single most significant step-up in UK marine protection in a generation: banning the destructive, seabed-scraping gear from over 30,000 square kilometres of our most precious offshore habitats.

We analyzed public data to see how big an impact this could make.

Paper Parks?

The UK’s offshore protected area consists of different types of MPA designations. MPAs are clearly defined sections of the sea established to conserve biodiversity and ecosystems. They’re supposed to be like nature reserves on land, only they’re on water. There are Marine Conservation Zones (MCZs), Special Areas of Conservation (SACs), Special Protection Areas (SPAs), Nature Conservation MPAs (a Scottish invention), and the newest, most buzzworthy title: Highly Protected Marine Areas (HPMAs). For now, there are only three pilot HPMAs in the UK.

Type of MPA	What It Protects	What’s Allowed	Where You’ll Find It
Highly Protected Marine Areas (HPMAs)	Whole ecosystems	🛑 No fishing, mining, or dumping; only research & navigation allowed	Few sites in England so far (e.g. Allonby Bay)
No-Take Zones (NTZs)	Everything inside	🛑 Nothing can be removed — not even a shell	Rare, small areas like Lamlash Bay in Scotland
Marine Conservation Zones (MCZs)	Specific habitats & species (e.g. seagrass, reefs)	Some fishing, dredging, or boating allowed, depending on the area	Mostly around England and Northern Ireland
Nature Conservation MPAs	Scottish marine wildlife & habitats	Activities may be managed or limited	Scottish seas
Special Areas of Conservation (SACs)	Protected habitats & animals (e.g. dolphins, sandbanks)	Must avoid damaging key features	Around UK coasts and offshore
Special Protection Areas (SPAs)	Seabirds & migratory birds	Activities controlled to reduce disturbance	Coastal and offshore bird hotspots
Ramsar Sites	Wetlands of global importance	Managed like nature reserves	Coastal marshes, lagoons, estuaries
Sites of Special Scientific Interest (SSSIs)	Important coastal/intertidal features	Regulated activity on land & shore	All around UK coastline
Historic MPAs	Shipwrecks & underwater heritage	Diving and anchoring need permission	Few sites, mostly in Scotland
Demonstration & Research MPA	Innovative conservation trials	Carefully managed activity	Only one site in Scotland

Each of these comes with its own particularities, but perhaps the biggest challenge with this MPA network is something called the “feature-based” approach. It sounds technical, but the concept is simple. Instead of protecting an entire site, the rules often only protect specific, approved “features”. This could be a species or a particular type of habitat.

In practice, this often means they don’t offer blanket protection to all species. Instead, they aim to safeguard certain “designated features” within their boundaries. These features might include specific species, like grey seals, habitats like seagrass beds, or unique geological formations like reefs. Critics of this ‘feature-based’ approach argue that it is ecologically unsound, with one 2020 study recommending “moving to comprehensive management measures for sites that deliver ecosystem-based conservation.” Another recent study noted that “it is regularly argued that protecting wider ecosystems in MPAs beyond designating features is vital to protect ecosystem processes.” The UK Parliament itself seems to acknowledge these shortcomings and has proposed to expand the bottom-trawling ban.

For most MPAs in the UK, industrial fishing activity largely persists. But some types are considered more harmful than others.

“Not all of the fishing industry is a major threat,” says Sam Fanshawe, a Senior UK Projects Manager at Blue Marine Foundation, an oceans conservation charity. “Bottom trawling and dredging are the key threats, these are the main challenges to most marine protected areas”.

A 2022 report from the Marine Conservation Society found that only 5% of the UK’s MPAs had full protection from bottom-towed fishing gear, a practice widely considered among the most destructive for seafloor ecosystems. This type of fishing is still prevalent in several UK MPAs, including the ones considered in this consultation.

43 MPAs Up for Enhanced Protection

The MMO’s proposals could create blanket bans on bottom trawling and dredging across vast swathes of 43 English offshore MPAs.

In response to our queries about the consultation, a spokesperson for the MMO said: 

“Following our consultation, we will need time to consider all responses that are received, including any additional evidence. This length of time this will take is dependent on the number and complexity of responses,” an MMO spokesperson told us. The MMO, however, did not respond to our findings before publishing. 

Our analysis reveals, for the first time, the potential scale of damaging fishing allegedly occurring under the “protected” label. We focused on the MPAs discussed in the consultation.

We carried out an analysis of data on 39 out of 43 UK MPAs for which the government is considering expanding protection measures. We analyzed publicly available data from Global Fishing Watch (GFW) from 2012 to September 2025. GFW works by tracking vessel data, primarily from a ship’s Automatic Identification System (AIS), combined with satellite imagery, and then applies machine learning algorithms to this data to identify individual vessels and interpret their movement patterns. The algorithms attempt to distinguish between a vessel that is simply traveling and one that is actively fishing, based on its speed, direction, and time spent in an area.

Using this, our analysis suggests 43,056 hours of combined apparent trawling and dredging in the MPAs considered in the consultation in 2024, the equivalent of one boat dragging its gear across the seabed, non-stop, for nearly five years. 

“They have been up until recently, especially offshore, entirely paper parks,” says Fanshawe.

Apparent fishing activity for 39 UK MPAs currently under review by the MMO. The records are for 2024 using data from Global Fishing Watch. Note: the available data doesn’t enable us to differentiate between trawling and bottom trawling.

This figure has been even greater in the past. An average of 50,000 hours of apparent harmful fishing activity has been recorded over the past eight years within these MPAs.

For the most part, this isn’t the work of a few small boats or local fishers. The GFW data suggests a vast industrial effort, with at least 484 trawlers and 38 dredgers active in these supposedly protected waters last year. Our analysis found multiple MPAs where over 90% of all fishing activity is represented by trawling and/or dredging activity. In sites like the Fulmar MCZ  in the North Sea, for instance, almost all the fishing activity allegedly comes from trawlers. Out of the 39, the MPA with the highest number of recorded fishing hours from trawlers or dredgers is the Western Channel MCZ.

In 2024 alone, the Western Channel MCZ endured 8,746 hours of apparent trawling and dredging, according to GFW data. That’s almost a full year of continuous industrial gear contact with a seabed designated to protect fragile sandbanks and reef habitats. Not far behind is South West Deeps (East), a large MPA located in the Western Channel and Celtic Sea region, which withstood nearly 4,600 hours of trawling last year. The average for the past few years is even higher.

MPA Name	Total Harmful Hours	Trawling Hours	Dredging Hours	Avg Hours/Year
Western Channel MCZ	51,175	47,333	3,842	7,311
South West Deeps (East) MCZ	50,344	50,344	0	7,192
South West Approaches to Bristol Channel MCZ	46,639	44,607	2,032	6,663
Foreland MCZ	27,966	27,909	56	3,995
Greater Haig Fras MCZ	18,364	18,364	0	2,623
South West Deeps (West) MCZ	17,585	17,585	0	2,512
North Norfolk Sandbanks & Saturn Reef SAC	17,395	17,394	1	2,485
Holderness Offshore MCZ	15,221	12,367	2,854	2,174
Inner Bank MCZ	14,605	13,006	1,599	2,086
Fulmar MCZ	13,486	13,486	0	1,927

Top 10 MPAs by total apparent harmful fishing activity, cumulative amount from 2018-2024 using GFW data.

Our analysis details a core group of 38 dredgers whose names appear repeatedly in GFW data.  One dredger alone allegedly logged over 900 hours of apparent dredging in a single year, raking through hotspots like the Western Channel. Another dredger spent over 770 hours in these protected zones, per the data.

The trawling fleet is even larger. At least 484 trawlers allegedly logged over 37,000 hours of apparent bottom trawling in these MPAs last year. The vessels with the most recorded hours of apparent fishing include several international ships, including two French-flagged ships that allegedly spent over 1,400 combined hours on apparent fishing, according to the GFW data. This is all perfectly legal at the moment under current UK rules.

In the Fulmar MCZ, trawling accounted for 99.9% of all apparent fishing activity in 2024, according to our analysis. Bottom trawls are the default industrial fishing method for demersal species (cod, haddock, flatfish), and their ecological footprint is substantial.

Take the ocean quahog (Arctica islandica), a clam that can live for over 400 years, or the fan mussel (Atrina fragilis), a rare species the size of a dinner plate. Both can be devastated by trawl passes, and recovery — if it happens at all — takes centuries.

Even humble habitats like circalittoral muds and sandbanks play important roles in marine ecosystems. They host entire communities of creatures that keep nutrients cycling, oxygenate sediments, and provide nurseries for commercial fish species. Lose those, and you lose the productivity that makes fishing possible in the first place.

“Perhaps the thing we’ve been pushing for most and are very concerned about is the lack of responsibility taken by the central government for managing its MPAs,” says Fanshawe.

Furthermore, the data does not capture one important facet of the issue: local communities. Evidence shows that community participation and involvement in MPA governance tends to lead to more positive outcomes. While we cannot gather a representative sample of fishers’ opinions, some local fishermen we have interviewed have expressed concerns about their voices being ignored in the past, even when asking for more stringent conservation measures such as lower fishing quotas.

Bob King, a local fisher from Lyme Bay, an inshore MPA near Dorset, recalls one instance when he was told by government officials that fishing stocks were healthy enough to raise quotas, even when local fishers were saying the opposite.

“We just felt totally ignored. So you sort of despair and think ‘what’s the point of talking to these people if they don’t listen to you?’,” he said. 

An Important Decision

The UK is weighing new fishing restrictions across 43 marine areas, with the consultation closing on September 29.

The Marine Management Organisation (MMO) estimates the cost to businesses at around £530,000 a year — about £7.8 million over two decades. But the environmental benefits are projected to be far greater, worth roughly £3.1 billion over the same period.

Bottom trawling, which drags heavy gear across the seabed, is identified as one of the most damaging practices, releasing carbon stored in sediments and destroying fragile habitats. Even gear considered less harmful, such as lobster pots and crab traps, can leave scars on the seafloor. Ropes may drag across habitats, pots crush vulnerable species, and abandoned “ghost gear” continues to trap marine life. Slow-growing species like fan mussels are especially at risk.

The figures highlight a stark imbalance: while the financial impact on businesses is limited, the long-term environmental costs are measured in the billions. 

Regulators must now decide whether the proposed protections will go ahead.

You can access the full data we gathered, including apparent harmful fishing records by MPA and vessel here. Our analysis is based on Global Fishing Watch data and comes with inherent limitations that can be consulted here.

This article was supported by a grant from the Earth Journalism Network.