CRIMINAL CAPITALI$M
Two studies reveal global patterns of industrial fishing across marine protected areas
Summary author: Walter Beckwith
image:
Aerial view of Bikar Atoll, with southern tip and Bikar Islands in the foreground. The National Geographic Pristine Seas team, in collaboration with the Marshall Islands Marine Resources Authority (MIMRA) and the Government of the Marshall Islands, conducted an expedition to the remote atolls of Bikar, Bokak, Bikini, and Rongerik. This expedition was in support of Reimaanlok, the Marshallese national framework for the planning and establishment of community-based conservation areas. In 2025, the Republic of the Marshall Islands established their first national marine sanctuary — which covers 48,000 square kilometers of water — providing an exceedingly rare glimpse into a pristine part of the Pacific Ocean.
view moreCredit: Steve Spence, National Geographic Pristine Seas
In two separate studies leveraging satellite imagery and artificial intelligence techniques, researchers reveal patterns of industrial fishing in coastal marine protected areas (MPAs) worldwide. Collectively, the findings, which may seem contradictory, show that although industrial fishing vessels are present in many protected areas worldwide, MPAs with the highest levels of protection remain largely unfished. Both studies suggest that proper investment in protected areas will pay off and that synthetic aperture radar (SAR) satellite technology could be one of the key tools used to safeguard the ocean’s future sustainability. Roughly 8% of the global ocean is formally protected, with ambitious international targets aiming to more than triple that coverage by 2030. While such protections can yield substantial long-term benefits, especially when paired with adequate fisheries management, potential gains are often compromised by inadequate regulations. In many cases, destructive, illegal, or unreported fishing practices persist even within designated protected areas due to insufficient safeguards. Global-scale monitoring of industrial fishing, including within MPAs, has been aided by the emergence of automatic identification system (AIS) data, which tracks the activity of individual vessels. However, not all vessels are required to use it. Many disable their transponders to avoid detection, making it difficult to obtain reliable, large-scale estimates of fishing pressure within MPAs. As a result, the true effectiveness of MPAs worldwide remains poorly understood.
In one study, Jennifer Raynor and colleagues analyzed 455 coastal MPAs classified as “fully” or “highly” protected under the MPA guide, an assessment framework that evaluates protections based on both regulations and management practices. These categories fully ban industrial fishing within their bounds. Raynor et al. combined AI methods with a recently published global SAR satellite imagery dataset to directly identify industrial fishing vessels operating within MPAs, regardless of whether their AIS is active. The authors found that, overall, very little unauthorized industrial fishing activity occurs in MPAs that prohibit it, averaging just one vessel detected per 20,000 square kilometers – a rate 9 times lower than in unprotected exclusive economic zones. Although a few MPAs in East and South Asia showed higher vessel densities, these cases were outliers driven by small geographic areas and sporadic detections. Only seven MPAs worldwide had vessels present on more than half of observed days, highlighting how rare such activity is in strongly protected areas. Raynor et al. also demonstrate SAR imagery’s reliability in detecting unauthorized fishing vessels. Not only did the method successfully identify AIS-broadcasting vessels with high accuracy, it also detected vessels in 163 MPAs where AIS data showed none, particularly in regions like Southeast Asia, where AIS is often incomplete.
In another study, Raphael Seguin and colleagues quantified fishing activities across a larger group of 6021 coastal MPAs representing a wide range of protective categories as outlined by the International Union for Conservation of Nature (IUCN) management framework. Using the same SAR dataset and deep learning models, Sequin et al. discovered that nearly half of the MPAs evaluated showed evidence of industrial fishing at levels in many cases matching or exceeding those in nearby unprotected waters. According to the findings, industrial fishing vessels were detected in 47% of the world’s coastal MPAs. While stricter IUCN categories did correlate with reduced fishing, the authors concluded that factors such as MPA size and remoteness were more predictive of fishing presence than official protection category alone. In a Perspective, Boris Worm discusses the possible drivers underlying the differences in the two studies’ findings. “Many MPAs have been established quickly without strong protective regulations, meaningful consultation with local stakeholders, or appropriate management capacity. In some cases, this has resulted in “paper parks” that are recognized as protected areas but do not prevent harmful activities,” writes Worm. “Yet the available data show that where proper investments are made, industrial exploitation is curtailed, and protective measures are comprehensive, long-term benefits will accrue.”
This map shows two ways the researchers tracked industrial fishing activity over 2017-2021. The top panel uses signals from ships’ Automatic Identification System (AIS), which broadcast their location, speed, and identity. By analyzing these signals with artificial intelligence (AI), researchers can estimate where fishing is likely happening. However, some vessels turn off their AIS or don’t carry it at all. The bottom panel uses satellite-based radar (Synthetic Aperture Radar, or SAR) to spot these so-called “dark” vessels that would otherwise go undetected. SAR works by sending radar pulses to the ocean’s surface and measuring the reflections, allowing AI models to identify most vessels over 15 meters long even if they have no AIS. The map shows industrial fishing activity density estimated from AIS (average daily apparent fishing hours per 100 square kilometers) and the density of vessels detected by SAR (vessels per 100 square kilometers at the time of satellite flyovers). Points indicate the center of each marine protected area.
Credit
Jennifer Raynor, Sara Orofino, and Gavin McDonald
Data is available for the production of data visualizations. For more information, please contact Raphael Seguin at raphaelseguin@protonmail.com
Journal
Science
Article Title
Little-to-no industrial fishing occurs in fully and highly protected marine areas
Article Publication Date
24-Jul-2025
Satellites show that strictly protected marine areas exclude industrial fishing!
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A side-by-side comparison of fishing vessel data detected via AIS and those detected by SAR techniques.
view moreCredit: Illustration by Jennifer Raynor
Illegal fishing is a global problem that threatens the health of ocean ecosystems and the economic viability of the fishing industry. Marine protected areas (MPAs)—zones set aside to safeguard marine life—are a key tool for conservation, but monitoring them has been a long-standing challenge.
Researchers led by the University of Wisconsin–Madison’s Jennifer Raynor showed that artificial intelligence methods applied to satellite data provide a powerful new way to assess industrial fishing activity in MPAs, bridging blind spots in current monitoring methods. The first-of-its-kind study, published in the journal Science, found that the world’s most strongly protected MPAs had little-to-no industrial fishing activity.
"We found that MPAs with strict legal fishing bans work better than critics claim,” says Raynor, a professor of natural resource economics in UW–Madison’s Department of Forest and Wildlife Ecology. “MPAs can help to regenerate fish populations, which creates strong incentives for illegal fishing—and yet, that activity was mostly absent. This is good news for marine conservation.”
Strongly protected MPAs had significantly less fishing activity than surrounding waters, averaging nine times fewer fishing vessels per square kilometer than unprotected coastal areas. In addition, 25% of MPAs had no fishing vessels present from 2017 to 2021.
Raynor and her colleagues at National Geographic Pristine Seas and the University of California, Santa Barbara, analyzed 1,380 MPAs that ban industrial fishing. Located within the world’s exclusive economic zones (EEZs), or waters under the jurisdiction of coastal nations, they captured 2.1% of the global ocean by area, including Australia’s Great Barrier Reef and Hawaii’s Papahānaumokuākea Marine National Monument.
First, the researchers examined 5 billion real-time vessel locations from the Automatic Identification System (AIS), which broadcasts vessel identity, position, course and speed to shore-based receivers to support marine safety. The AIS analysis showed little apparent fishing effort during the five-year study period. However, not all vessels are required to use the system, and captains can disable transponders or tamper with location broadcasts to evade detection. In addition, AIS is unreliable in areas with poor signal reception, such as parts of Southeast Asia.
To track the “dark vessels” that are absent from AIS data, the researchers used images created by satellites that send radar pulses to the ocean surface and measure the reflected signals (SAR, or synthetic aperture radar). A previous study showed that analyzing these reflectance patterns with AI methods reliably identified fishing vessels more than 15 meters long.
The new analysis detected just one vessel per 20,000 square kilometers (7,722 square miles), on average, in 455 MPAs with the highest imaging frequency during the study period, corroborating the AIS results. Expanding the sample to 638 MPAs with at least one satellite image increased the proportion with no vessel detections from 25% to 42%. This strengthened the argument that little-to-no industrial fishing activity occurred in MPAs that ban this activity.
Importantly, the AIS data missed almost 90% of SAR-based fishing vessel detections. This was compelling evidence that relying on AIS-based monitoring alone is problematic, especially in areas with low adoption rates, frequent tampering, or poor signal reception. Resource-limited nations can collaborate with nonprofit organizations like Global Fishing Watch to enhance their ocean monitoring efforts with satellite-based tools, says Raynor.
By helping the ocean recover from fishing pressure, MPAs boost biodiversity inside their boundaries. But they also provide spillover benefits. "Because strictly protected marine areas discourage illegal fishing, fishes are far more abundant within their boundaries, they produce many more babies, and help replenish surrounding areas,” says Enric Sala, a marine ecologist and founder of Pristine Seas, which funded the study. “In other words, the fishing industry benefits from following the rules.”
Previous research showed, for example, that the fishing restrictions in the no-take Papaānaumokuākea Marine National Monument increased catch rates of yellowfin and bigeye tunas around it.
Raynor hopes the new findings will help shape global policies for future MPAs. “By using satellites to track fishing vessels, countries can predict the locations of illegal activities and target patrol efforts, saving both manpower and money,” she says. “This is critical for reaching the Global Biodiversity Framework’s 30 by 30 target, which aims to protect 30% of oceans by 2030.”
Special Notes to Reporters: More information, including a copy of the paper, can be found online at the Science press package at https://www.eurekalert.org/press/scipak/.
Journal
Science
Method of Research
Data/statistical analysis
Subject of Research
Animals
New research: Satellite imagery detects illegal fishing activity, shows strict protections work
The first-of-its-kind study reveals that the world’s most strongly protected marine reserves successfully curb industrial fishing activity, offering a new way to assess fishing compliance and bridge blind spots in current monitoring methods.
Washington, D.C. (July 24, 2025) — New peer-reviewed research in the journal Science demonstrates the power of strict legal bans against industrial fishing in marine protected areas (MPAs). The analysis — which combines satellite imagery and artificial intelligence technology to detect previously untraceable vessels — reveals that most of the globe’s fully and highly protected MPAs successfully deter illegal fishing. The study is the first of its kind to demonstrate that the most strictly protected marine reserves are well respected and are not simply “paper parks.”
The study, “Little-to-no industrial fishing occurs in fully and highly protected marine areas” finds that:
- 78.5% of the 1,380 MPAs studied had no commercial fishing activity;
- Of the MPAs where satellite images detected illegal fishing activity, 82% of them averaged less than 24 hours of activity per calendar year;
- Strongly protected MPAs had, on average, nine times fewer fishing vessels per square kilometer than unprotected coastal areas; and
- MPAs designated as strictly-protected with significant fishing activity included those in the Chagos Marine Reserve, the South Georgia and South Sandwich Islands and the Great Barrier Reef Marine Park (combined with the Great Barrier Reef Coast Marine Park), each with approximately 900 hours per year.
“Because strictly protected marine areas discourage illegal fishing, fishes are far more abundant within their boundaries, they produce many more babies, and help replenish surrounding areas,” remarked Enric Sala, one of the study’s co-authors, a National Geographic Explorer in Residence, and founder of Pristine Seas. “In other words, the fishing industry benefits from following the rules.”
Illegal fishing poses a significant global threat, jeopardizing both the health of ocean ecosystems and the economic stability of the fishing industry. Scientific evidence shows that strictly protected MPAs restore marine life within their boundaries, improve local fishing, provide jobs and economic benefits, and build resilience against a warming ocean. But when MPAs are minimally or lightly protected, the benefits practically disappear.
“The ocean is no longer too big to watch. With cutting-edge satellites and AI, we’re making illegal fishing visible and proving that strong marine protections work,” said Juan Mayorga, a scientist with Pristine Seas and co-author of the study.
To arrive at their conclusions, researchers analyzed five billion vessel positions from the Automatic Identification Systems (AIS), a GPS-based safety signal transmitted by many industrial fishing vessels, and paired this with satellite images generated by Synthetic Aperture Radar (SAR), which can detect vessels regardless of weather or light conditions. The combination of the datasets — and the use of AI models developed by Global Fishing Watch — allowed researchers to detect the majority of fishing vessels over fifteen meters long, including so-called dark vessels that do not broadcast their location and often operate to evade detection.
“No single dataset can solve the challenge of monitoring fishing activity at sea; each has its blind spots,” asserted Mayorga. “But when we combine them, their power emerges. By fusing AIS tracking with satellite radar imagery and AI, we are now much closer to the full picture of human activity across the ocean. That’s especially important in the crown jewels of the ocean — the world’s most strongly protected areas — where the stakes for enforcement and biodiversity are highest.”
Researchers found that the AIS data missed almost 90% of SAR-based fishing vessel detections within these MPAs. Inaccurate data, limited resources and the vastness of the ocean have made effectively monitoring MPAs for industrial fishing a challenge. This groundbreaking methodology offers a powerful new way to assess fishing compliance and bridge blind spots in current monitoring methods, the authors found.
“By using satellites to track fishing vessels, countries can predict the locations of illegal activities and target patrol efforts, saving both manpower and money,” said Jennifer Raynor, the study’s lead author and a professor of natural resource economics in UW–Madison’s Department of Forest and Wildlife Ecology.
A growing body of research shows that MPAs produce spillover of fishes and invertebrates that increases the catches of species from small and sedentary (lobsters, scallops) to large and migratory (tuna). A 2024 study revealed that fishing catch per unit effort increases, on average, 12% to 18% near the boundaries of large fully protected MPAs.
“Illegal fishing takes place in areas of the ocean set aside for protection, but using satellites we have found — for the first time ever — that the level of protection determines how much risk industrial fishers are willing to take on,” Sala remarked. “Fully and highly marine protected areas discourage illegal fishing. The stricter the rules in place to conserve ocean areas, the more benefits nations receive — including more fish to be caught outside protected areas’ boundaries.”
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Note to Reporters:
Visuals, for editorial use with proper credit, can be found in our press kit. Credit and caption information is included.
More information, including a copy of the paper, can be found online at the Science press package at https://www.eurekalert.org/press/scipak/.
National Geographic Pristine Seas
Pristine Seas works with Indigenous and local communities, governments, and other partners to help protect vital places in the ocean using a unique combination of research, community engagement, policy work, and filmmaking. Since 2008, our program has conducted nearly 50 expeditions around the world and helped establish 30 marine reserves, spanning more than 6.9 million square kilometers of ocean.
Pristine Seas is part of the global non-profit, the National Geographic Society. Our mission is driven by science and filmmaking — we are fully independent from National Geographic publishing and its media arm.
Journal
Science
Method of Research
Data/statistical analysis
Subject of Research
Not applicable
Article Title
Little-to-no industrial fishing occurs in fully and highly protected marine areas
Article Publication Date
24-Jul-2025
