Lyme Bay, depicted here, is a landmark marine protected area in the UK. Image credits: Andrei Mihai / ZME Science.

Around the UK, hundreds of marine protected areas (MPAs) appear on maps as blue sanctuaries for ocean life. In theory, these sanctuaries should function like national parks for the sea, enabling marine life to recover from decades of human pressure.

However, despite the label, many of these so-called MPAs remain open to damaging practices such as bottom trawling and dredging, prompting conservationists to call some of them “paper parks.”

To understand this apparent divide, ZME Science launched an in-depth analysis supported by a grant from the Earth Journalism Network. Using open, science-backed vessel tracking data from Global Fishing Watch (GFW), we have analyzed more than a decade’s worth of fishing activity across dozens of MPAs. The datasets revealed patterns that would otherwise remain invisible: trawlers apparently operating inside protected zones, persistent pressure on vulnerable seabeds, and long-term trends that challenge the notion that these waters are truly safeguarded.

In 2024 alone, data shows over 43,000 hours of apparent trawling and dredging inside 43 MPAs for which the Marine Management Organisation (MMO) launched a public consultation earlier this year. These 43 MPAs collectively cover 30,000 km² of seabed, and the MMO is considering completely banning bottom trawling and dredging in these areas.

From 2016 to 2024, the average was even higher — around 50,000 hours annually. Hundreds of trawlers and dozens of dredgers were at work inside these MPAs that currently only offer feature-based protection (i.e., bylaws protect only particular species or habitats rather than the entire site).

The tool we built is extremely simple to use, just ask for an MPA and a time frame.

As the analysis grew, so did the realization that this information shouldn’t stay locked behind doors. So ZME Science built an interactive web app that lets anyone explore fishing activity in UK MPAs; no technical skills required. You simply use the app and ask for a report for an MPA and a timeline, and you get the data.

Powered by the GFW API, the tool visualizes years of AIS-derived vessel data, making it easy for journalists, researchers, policymakers, and the public to see what’s happening in UK MPAs. The source code is open on GitHub.

Why Keep an Eye on Trawling

Conservation isn’t simply about blanket fishing bans; that just won’t work in today’s world. A more realistic solution is to allow fishing within sustainable limits, especially the types of fishing that aren’t too damaging.

“Not all of the fishing industry is a major threat,” explains Sam Fanshawe, a Senior UK Projects Manager at the conservation charity Blue Marine. “Bottom trawling and dredging are the key threats”.

In this type of bottom trawling fishing, heavy, weighted nets are dragged along the seabed, crushing delicate fauna and centuries-old cold-water corals. This practice and its environmental impacts have been detailed by researchers for decades. This destruction goes beyond biodiversity. The seabed is a massive carbon store. When trawlers plow through sediments, they release some of that carbon, turning a potential climate solution into an emissions source.

Yet bottom trawling remains perfectly legal in many MPAs.

A big reason why is that the UK practices a “feature-based” approach. An MPA is designated to protect one or several features (say, a type of gravel or a specific clam). As long as the trawlers avoid that specific rock or clam bed, they can legally scourge the rest of the “protected” area. This approach has been widely criticized by scientists as ecologically unsound, resulting in a fragmented map that offers fewer environmental benefits.

Furthermore, as marine governance expert Peter Jones from University College London points out, the features that we are left with nowadays “are often relics, small parts of the features we had in the past.”

So there’s still a lot of bottom trawling and dredging happening in protected areas, and it makes sense to track and report on it. You can also read our full-length article on Lyme Bay, the UK’s landmark case for marine recovery, and our large-scale analysis of MPAs considered for extra protection.

What This Data Can and Can’t Do

It used to be nigh impossible to get data from the open sea. That has changed, as several countries (including the UK) require larger fishing ships to use an Automatic Identification System (AIS)—a GPS-like technology that broadcasts ships’ location, identity, and speed. Satellites and ground stations pick up these pings, allowing services like Global Fishing Watch to harvest tens of millions of vessel positions every day.

To distinguish a ship that is simply traveling from one that is actively fishing, the GFW system uses two sophisticated machine learning models. The first model acts as a profiler, combining official vessel registries with movement data to identify the ship’s type and gear. The second model acts as a behavior detector: trained on thousands of manually labeled vessel tracks, it recognizes the specific “dance” that indicates the boat is fishing. Maneuvers such as slowing down and jagged turning patterns are typical of trawling. This is logged as “apparent fishing activity.”

However, this digital view of the ocean has significant blind spots. The data captures only a small fraction of the global fleet—roughly 100,000 of an estimated 3.3 million fishing vessels. It is heavily biased toward large industrial ships (over 24 meters) and wealthier nations, which should be okay for the UK, though. Furthermore, historical increases in data often reflect better satellite reception rather than more fishing, meaning this map represents a conservative estimate of industrial pressure rather than a complete census of the sea.

The most significant application here, however, is that the current system can’t differentiate between bottom trawling and mid-water trawling (which is not *as *damaging). This core limitation means there are many instances in which we cannot confidently assess whether bottom trawling is happening, or whether it’s mid-water trawling.

Some ships may also have out-of-date identifiers or there may be errors. Still, with these limitations in mind, the data can be very relevant. Our tool makes it extremely easy to generate insightful reports for individual MPAs. Here are a few relevant examples that showcase how we envision this data being potentially used.

Case Studies: West of Scotland

The West of Scotland Marine Protected Area (MPA) stands as the largest designated marine sanctuary in the United Kingdom, covering a staggering 100,000 square kilometers. It’s an area larger than the landmass of Scotland itself. Located in the deep waters of the North-East Atlantic to the west of the Outer Hebrides, this MPA is meant to protect a complex deep-sea ecosystem that includes steep continental slopes, sedimentary plains, and two isolated seamounts. Its protected features are incredibly diverse, ranging from different types of corals to deep-sea sponge aggregations and rare fish species like the leafscale gulper shark, Portuguese dogfish, and orange roughy.

The site was formally designated in late 2020, and this appears to have had some effect. While it’s difficult to disentangle the effects of the pandemic and draw a clear cause-and-effect, fishing in the West of Scotland MPA substantially decreased after 2020, according to an analysis using our tool. This is further corroborated by the decrease in the number of fishing ships active in the MPA.

Apparent fishing and trawling hours in the West of Scotland MPA for the 2012-2025 period. Image from ZME Science MPA App. Total fishing hours and number of vessels active in the West of Scotland MPA for the 2012-2025 period. Image from ZME Science MPA App

However, in October 2025, the Scottish Government implemented major new fisheries management measures that fundamentally changed its status. Under these new regulations, the West of Scotland MPA became one of a select few sites to receive “full site” protection, with prohibitions on demersal mobile gear (such as bottom trawls) and demersal static gear implemented across the entire area. This move was part of a broader package protecting over 90% of Scotland’s offshore MPA network from bottom-towed gear, marking a decisive shift from designation to genuine enforcement.

If this is confirmed, we would expect a significant downturn in trawling activity, which could be verified with our app.

So far, the data seems to be unclear. There’s not an apparent drop in trawling in the MPA, but this could be midwater trawling as opposed to bottom water trawling.

Total fishing hours and number of vessels active in the West of Scotland MPA for the past three months. Image from ZME Science MPA App.

This data can be a starting point for more complex investigations. For instance, in the image below, you can see the apparent fishing intensity in 2025 represented in color: the more intense the light green, the more the apparent intense fishing effort. The West of Scotland MPA is highlighted, showing that industrial fishing is much more active right on the border and outside of it. This appears to be a common trend for several MPAs, suggesting that MPA protection can work in one sense, with one important mention.

“The fish move around, they don’t stay in the boundaries. At the end of the day, it doesn’t matter if they’re fished inside or outside the MPA, their numbers are still the same. MPAs alone will never be effective, not unless they’re part of a wider sustainable use strategy,” Jones told ZME Science in a previous interview.

However, another common trend is for such MPAs to have ships skirting on the very edge, often in the “ambiguous” area of the GPS uncertainty.

The red path indicates the 2025 apparent fishing activity of the Margiris, one of the largest “supertrawlers” identified by Greenpeace earlier this year as active in UK waters.

Image from GFW.

This trend of skirting the edge also appears to be the case for the Maartje Theadora, the flagship of the German deep-sea fishing fleet. The ship, whose apparent fishing effort in November is marked in orange on the map below, is also skirting the edge of the MPA after bottom trawling has been banned.

While this is only a single month of observation, it suggests that some big trawlers operate in the “twilight” zone, where it’s impossible to say if they’re right outside or right inside the MPA. Our data may flag them as inside the MPA, but there is some ambiguity.

Image from GFW starting November 1, 2025.

Case Studies: Dogger Bank

The Dogger Bank Special Area of Conservation (SAC) is a vast, shallow sandbank in the southern North Sea, recognized as the largest of its kind in UK waters. The protected area also extends into German or Dutch waters. It was designated to protect its unique seabed habitat, a productive ecosystem that supports a wide array of marine life, including sand eels, flatfish, and hermit crabs, which in turn feed seabirds and marine mammals.

However, for years following its designation, the site became emblematic of the “paper park” phenomenon: despite its protected status, it was subjected to intense bottom trawling by both UK and EU vessels, legally scouring the very seabed it was meant to preserve.

The situation reached a breaking point due to sustained pressure from conservation groups. In 2020, Greenpeace took direct action by dropping large, inert granite boulders onto the seabed to physically prevent trawlers from operating, while the Blue Marine Foundation threatened legal action against the government for failing to uphold conservation laws.

Ultimately, this led to a policy shift, and in 2022, the UK government finally introduced bylaws implementing a total ban on bottom-towed fishing gear across the entire site. This decision marked a significant turning point in UK marine management and was hailed as a success story, as bottom trawling rapidly decreased in the region after 2022.

But the data suggests that overall fishing is increasing, and trawling is also on the rise, though it is not clear if this is bottom trawling or mid-water trawling.

Apparent fishing and trawling hours in the Dogger Bank MPA for the 2015-2023 period. Image from ZME Science MPA App.

Our analysis also highlighted the boats that are the most active in this MPA. This can serve as the starting point for another investigation.

Most active ships in the Dogger Bank MPA for the 2015-2023 period. Image from ZME Science MPA App.

We encourage people not to stop at this and use it as a starting point to “dig” further. For instance, let’s say we wanted to explore what kind of trawler the Enterprise II is and what its fishing activity looks like.

We can easily go back to the main Global Fishing Watch website and know exactly what to do. In this case, judging by the apparent fishing activity, the trawler systematically operated in the Dogger Bank MPA.

Activity of the Enterprise II in the Dogger Bank MPA starting August, 2023.

We can then explore its identifier (the Maritime Mobile Service Identity or MMSI) and try to learn more about it. Was it midwater trawling or bottom trawling?

Mistaken identity?

Unfortunately, the information is less clear. The ship is registered as “BF-1”. BF stands for Banff, a port in Scotland. Historically, the “BF” registered vessels primarily target whitefish (cod, haddock, monkfish) or prawns (Nephrops). This is also supported by a photo of the vessel that claims the company owning it targets fish like haddock or monkfish. Both of these fish are often targeted with bottom trawling. Midwater trawls are generally much larger than bottom trawls, and the dimension of this ship fits with the potential of a bottom trawler.

You could have a reasonable suspicion of bottom trawling.

However, this is a good example of why this data should be analyzed with great care. In recent times, this ship appears to have taken on different, non-fishing duties. It is reportedly working as a guard. When we plotted the offshore infrastructure elements, it appears that this ship was positioned in the vicinity of offshore wind farms in the Dogger Bank. This makes it likely that the ship wasn’t fishing at all in this region. Again, the data is not an immediate confirmation and must be interpreted with care.

Case Studies: South West Deeps (East)

Located approximately 190 kilometers southwest of the Land’s End peninsula, the South West Deeps (East) is a vast Marine Conservation Zone (MCZ) and one of the most fished MPAs in British waters.

The site is defined by its significant depth (dropping to 750 meters) and its extensive “shelf-break” features, where the continental shelf descends into the deep ocean. These subtidal sand and mud habitats act as vital carbon stores and support a complex ecosystem of burrowing megafauna, clams, and marine worms. The area is also biologically significant due to the seasonal “Celtic Sea Front,” a mixing zone of nutrients that drives high plankton productivity and supports the wider marine food web.

Despite being designated in 2013, the South West Deeps (East) has become a case study for the controversy surrounding “paper parks.” For over a decade post-designation, it remained one of the most heavily fished MPAs in Britain, subjected to thousands of hours of bottom trawling annually, primarily by French and Spanish vessels.

We used our app to look specifically at trawling in this MPA, which has apparently grown substantially *after *the MPA designation.

In this case, we can look at what kind of trawlers are operating in these waters. Let’s focus on the first one on the list.

Yet again, we have the ship’s identification number (MMSI) and we can look up basic information about it.

The vessel is reporting its destination as Le Guilvinec. The vessel is associated with the Scapêche fleet (the fishing arm of the Intermarché supermarket chain). While Scapêche does own pelagic vessels, they operate under a separate division (“France Pélagique”). The Bougainville is part of their fresh-fish fleet, which targets bottom-dwelling species like monkfish, hake, and langoustine. More tellingly, a detailed French fleet/spotter site lists the ship as “Type de navire : Chalutier de fond” – bottom trawler.

It appears that this is a classic industrial bottom trawler. However, bottom trawling isn’t banned in this MPA.

Some Conclusions

“The world is littered with paper parks,” says Peter Jones, a researcher who has spent years analyzing the governance of marine protected areas. For decades, it has been difficult to assess the true state of these sanctuaries; it is even harder to monitor what happens when patrol boats are miles away.

This is where data transparency becomes a weapon for change. It strips away the opacity of maritime law. It allows anyone to see the boats raking through the Western Channel or to watch the intensity of dredging in the South West Deeps. It forces us to confront the reality that a line on a map does not stop a 30-ton net.

As imperfect as this data is, we hope that our tool can be a small cog in this mechanism.

But visualization is only one step.

“The fundamental problem is that we lack information on many MPAs,” Jones explains. “The further offshore we go, and the deeper the water becomes, the more the uncertainty increases”.

“So when you don’t have information, what do you do? Do you opt for a precautionary approach, or do you ask for evidence to support potential damage? I think we should focus on evidence, but I also think we have to err on the side of caution and have wider scale restrictions.”

Image credits: Richard Allaway.

To turn these insights into protection, the UK must navigate a murky divide between scientific certainty and political will. Yet, Jones says progress is happening.

“Until recently, the majority of MPAs beyond six nautical miles were paper parks. Yes, we used to have lots of offshore paper parks. We used to have a lot of inshore paper parks as well, but in the last 10 years, we’ve got rid of most of those. Now we are slowly catching up.”

“Broadly speaking, I think it’s safe to say we’re slowly shifting towards a whole site approach, and we should shift to a whole site approach for more MPAs, especially inshore MPAs. Tangible steps are being taken.”

But no matter how you look at it, MPAs have to be components of wider-scale ecosystem management.

This brings us back to the core purpose of opening up this data: accountability. While technology alone cannot restore a reef or replenish a fish stock, it removes the veil of invisibility that has allowed “paper parks” to persist for so long. As the UK (and the world) navigates the difficult shift from passive designation to active enforcement, continuous monitoring will remain vital to push for real protection.