Supertrawlers spent 7,380 hours fishing in UK Marine Protected Areas each year since Brexit

An investigation by Greenpeace UK reveals today that giant supertrawlers relentlessly continue to catch fish in the UK’s Marine Protected Areas, damaging precious marine habitats and fish populations, despite the UK government having had the powers to stop them since Brexit and committing to protect at least 30% of UK waters by 2030. 

Investigators found that from January 2020 to January 2025, 26 supertrawlers spent significant time fishing in 44 of the UK’s offshore Marine Protected Areas (MPAs).[1] Collectively these monster vessels spent 4.2 years, nearly 37,000 hours, fishing in MPAs in the last five years. On average they spent 7,380 hours fishing in our MPAs every year.[2] The majority of these vessels were foreign-flagged, selling most of their catch overseas.

All these supertrawlers were operating legally despite the UK government having had the power to ban supertrawlers from operating in our waters since leaving the EU. The shocking figures revealed by Greenpeace UK today reflect half a decade of broken government promises on ocean protection during which time these ‘protected’ areas, designated for the conservation of habitats, species and processes essential for healthy marine ecosystems, have been exploited beyond sustainable limits. Marine Protected Areas have been found to boost fish populations significantly. Studies of both the Lyme Bay MPA in the UK and Cabo Pulmo National Marine Park in Mexico found that a whole site approach to MPA protection can boost the abundance and diversity of fish populations by as much as 400%. 

A previous Greenpeace investigation looked at supertrawler fishing hours in MPAs in 2019. This new investigation provides a fuller view of the situation in the five years since the UK left the EU and comes at a time when we have a new Labour government that has promised to deliver 30×30 in UK waters. The relative speed with which Russian flagged supertrawlers left our MPAs in 2023, shows that it is possible to remove supertrawlers from UK MPAs where there is the political will to do so. 

Supertrawlers are massive industrial freezer trawlers measuring more than 100m in length. They can catch hundreds of tonnes of pelagic fish species like herring and blue whiting in a day using enormous nets. Mackerel, one of the key targets for these vessels, has had catch limits set far in excess of scientific advice over the last decade. Due to their size and immense catch capability, supertrawlers also catch large quantities of non-target animals, or bycatch, including dolphins and porpoises as well as sharks, seals and rays. A less-known but equally damaging practice is high-grading, the discarding of low-value catches in order to preserve the quota for high-value fish, which is illegal. 

To make matters worse, the supertrawlers fishing in UK MPAs land the vast majority of their catch abroad so this hoovering up of fish gives little economic benefit to the UK. Supertrawlers’ large-scale and destructive industrial fishing methods affect the health and resilience of the whole marine environment including the fish stocks available to the UK’s small-scale fishing fleet, which does land almost all of its catch in the UK. Greenpeace UK’s investigation found that only ten MPAs accounted for more than 80% of all supertrawler fishing time calculated between 2020 and 2025, illustrating the immense pressure some MPAs are under. There are other types of destructive industrial fishing in MPAs like bottom trawling, which falls outside the scope of this investigation but which has been revealed by Oceana UK to also place pressure on MPAs. 

Erica Finnie, oceans campaigner at Greenpeace UK, said:

“The government is failing our protected seas. Marine Protected Areas should be places for fish, marine biodiversity and habitats to rest and recover from the damage caused by human activities. But the government is making a mockery of our MPAs by allowing these places to be routinely fished – despite having had the powers to ban industrial fishing vessels from protected waters since we left the EU. By allowing industrial fishing to continue in our protected areas, the government is degrading entire MPAs from the north of Scotland to the south of Cornwall. To be taken seriously as a leader on ocean protection, the UK government must ban supertrawlers, and other types of industrial fishing, from our Marine Protected Areas.”

Felix Lane, political campaigner at Greenpeace UK, said:

“The abject failure to protect our most sensitive marine habitats is a scandal that’s lasted five years too long. The Labour government must now ban destructive industrial fishing in our precious marine environments so it can deliver on its promises to protect 30% of waters domestically. And the government must also follow in the footsteps of the 18 countries, including France and Spain, that have already ratified the Global Ocean Treaty. This is the crucial legal tool which can protect 30% of global oceans by 2030. This July the UK also has the power to vote to stop deep sea mining before it starts, preventing a whole new extractive industry that would put pressure on our ocean biodiversity.”

The MPAs which Greenpeace investigators found to be most heavily fished by supertrawlers, in the last five years, were off the coast of Scotland, such as Wyville Thomson Ridge, West of Scotland, Central Fladen, Geikie Slide and Hebridean Slope and Faroe-Shetland Sponge Belt. Pobie Bank Reef, West Shetland Shelf, Seas off Foula, The Barra Fan and Hebrides Terrace Seamount were also highly fished by supertrawlers. These MPAs were set up variously to protect precious features like seamounts created by extinct volcanoes, stony reefs and soft corals. And they also support important species including crustaceans, deep-sea sponges, great skuas, fulmars, gulls and auks like puffins. We need a whole ecosystem approach to protecting MPAs, where all industrial fishing is banned, so biodiversity can thrive. 

Phil Taylor, Director of Open Seas, said:

“The UK has had a network of supposedly protected marine areas for a decade, yet damage continues to occur on a daily basis. This investigation shows that so often the businesses profiting from damaging our seas do little to strengthen our economy or food security. The Scottish Government recently ran a consultation on how best to manage fishing in offshore protected areas, but it was sadly clear that some proposals, such as those for the Central Fladen area, were far too weak to have the impact that’s needed. Government ministers must act now to end the harms caused by unmanaged trawling in marine protected areas, so that our seas can regenerate for future generations.”

The Southern North Sea MPA, off the east coast of England, was specifically created to safeguard harbour porpoises, which are threatened by supertrawlers. The most recent estimates indicate that over 1000 cetaceans are killed each year in UK fisheries. 

The five supertrawlers that investigators identified as having spent the most time fishing in UK offshore MPAs between 2020 and 2025 were Willem van der Zwan (flagged to Netherlands), Margiris (Lithuania), Helen Mary (Germany), Sch 81 Carolien (Netherlands) and Afrika (Netherlands).[2] The Margiris (143m) and Willem van der Zwan (142.5m) are two of the biggest supertrawlers on Earth. The German-registered supertrawler Helen Mary was detained in Cork, Ireland on 17 February for alleged fisheries offences. Investigations are ongoing. 

The data from Greenpeace UK’s investigation shows that Russian supertrawler operations in MPAs declined sharply, coming to a hard stop in 2023. However, the total fishing time in UK MPAs in 2024 was only 15% lower than in 2020 due to Dutch and German vessels increasing their fishing activity[2]. 

750,000 people have signed a petition in recent years calling for the UK government to ban supertrawlers and other destructive fishing vessels from the UK’s MPAs, demonstrating long-standing support for the government to act. Banning supertrawlers from fishing in MPAs would help ensure that at least 30% of the UK’s waters, and 30% of the global oceans, are fully protected by 2030 – a scientifically agreed target backed by the UK government. 

A 2022 Greenpeace UK report called All at Sea analysed the UK’s entire network of MPAs and found that 90% of UK MPAs were protected in name alone, with no meaningful, site-wide regulation on the most destructive fishing activity. 

Greenpeace UK has taken action against industrial fishing in the past, sailing alongside the supertrawler Maartje Theadora in a Marine Protected Area and dropping boulders in MPAs to physically defend them from industrial fishing while government protection was lacking. 

– Ends – 

A collection of supertrawlers photos and video are available in the Greenpeace Media Library. 

Contact: Alex Sedgwick, press officer at Greenpeace UK, alexandra.sedgwick@greenpeace.org, 07739 963301

Notes for editors: 

[1] Greenpeace investigators used AIS (Automatic Identification System) tracking data from Global Fishing Watch for all fishing vessels over 100m to assess the amount of time they spent fishing in UK MPAs from 31 Jan 2020 to 31 Jan 2025. The AIS tracking data is available from Global Fishing Watch. https://globalfishingwatch.org/ 

The full methodology is explained here. This is a different methodology from the one we used in previous research about supertrawlers’ activity in MPAs and therefore the data is not comparable. 

[2] The following tables are available here.

Table 1. Breakdown of fishing hours per year

Table 2. The EU owned supertrawlers operating in UK waters 2020-2025

Table 3. The non-EU owned supertrawlers operating in UK waters 2020-2025 

Table 4. The 44 UK offshore MPAs fished in by supertrawlers 2020-2025