Extensive survey of Eastern tropical Pacific finds remote protected areas harbor some of the highest concentrations of sharks

Puerto Ayora, Galapagos | 26 November, 2025 – One of the most comprehensive surveys to date of shark and other large predator fish in the Eastern Tropical Pacific (ETP) ocean finds that  remote Marine Protected Areas (MPAs)—including the Galapagos, Malpelo, Clipperton, and Revillagigedo islands—support some of the largest numbers of sharks reported globally, including the critically endangered scalloped hammerhead, while coastal MPAs are showing signs of severe depletion. 

“The oceanic islands of the Eastern Tropical Pacific represent a window into the past, where sharks and large predatory fishes are the norm and not the exception,” says Dr. Pelayo Salinas-de-León, Principal Investigator at the Charles Darwin Foundation and senior author of the study. “These areas provide a glimpse of what a healthy ocean looks like and highlight the key role ocean conservation plays in safeguarding these last strongholds from systematic overfishing”. 

The study, published in PLOS One today, was led by researchers from the Charles Darwin Foundation (CDF), in collaboration with National Geographic Pristine Seas, the Galapagos National Park Directorate and other regional research institutions. The research team used Baited Remote Underwater Video systems (BRUVs) to assess shark and other large predators in seven MPAs, including four oceanic (Galapagos, Malpelo, Clipperton, and Revillagigedo) and three coastal (Machalilla, Galera San Francisco, and Caño Island).  Using a similar assessment approach to the Global FinPrint initiative in other tropical regions of the world, the research closes a gap on knowledge about shark and other predator populations in the Eastern Pacific.  

“Oceanic islands, like Galapagos and Malpelo, are incredible places where extraordinary populations of sharks and other large predatory fishes – like jacks, groupers, and snappers – still thrive at a time when these fish are rapidly disappearing elsewhere,” explains Simon McKinley, lead author of the study. “The Marine Protected Areas around them combined with their remote location provide protection to marine communities from unsustainable fishing practices, allowing animals to live out their natural lives largely undisturbed.”

Additional study findings include:

• The oceanic island MPAs surveyed support abundant and diverse fish communities across all levels of the food web.  

• Most Galapagos sharks observed at Clipperton measured at juvenile sizes, suggesting that the MPA functions as an important nursery site. In contrast, mostly larger, mature individuals were measured at other island MPAs, indicating these sites serve as adult aggregation or foraging grounds. These findings highlight the complementarity of different MPAs in a regional network in protecting different habitats that support the different life-stages of sharks. 

• Predatory fish communities differed between the oceanic islands, likely influenced by regional currents and local environmental conditions such as temperature and food availability. The critically endangered scalloped hammerhead shark (Sphyrna lewini) was recorded most frequently in the southern MPAs of Galapagos and Malpelo, while the vulnerable silvertip shark (Carcharhinus albimarginatus) was the most commonly observed species in the northern MPAs of Revillagigedo and Clipperton. These patterns highlight how each Marine Protected Area harbors distinct marine communities, underscoring the need for management strategies tailored to their unique ecological conditions.

In contrast to assessments of the remote island MPAs, surveys of coastal MPAs revealed few large predators and low fish abundances, which are signs of a marine ecosystem under pressure. Scientists describe this trend as “fishing down the food web”, an unsustainable practice where the removal of large species, like sharks, means fishers catch smaller species at lower levels in the food web, ultimately leading to their extinction. 

“The fact that we observed only a small handful of sharks and large predatory fishes in these coastal MPAs is worrying. Especially as there are past records of them in these areas,” adds McKinley. “The sad reality is that, despite being within protected areas, these species have likely been unsustainably fished over time to the point that they have been partly or entirely removed from marine ecosystems.”

More than 77 MPAs have been designated in Mexico, Costa Rica, Panama, Colombia, and Ecuador, including oceanic islands within their Exclusive Economic Zones (EEZs). These MPAs vary in their level of protection, ranging from allowing extractive activities, to mixed-use management approaches, to fully protected no-take zones, where all human activity is strictly forbidden. 

“This study reinforces what we already know: strictly-protected marine reserves where extractive activity is banned is the best way to help the ocean recover,” remarked Enric Sala, National Geographic Explorer in Residence and founder of Pristine Seas who served as an author on the study. “But it also shows that when fishing is allowed in MPAs — as in many so-called ‘protected areas’ in the Eastern Tropical Pacific — they can’t replenish marine life. Minimally-protected MPAs simply aren’t able to offer the benefits that countries hope for.”

The study was conducted over a series of expeditions across the ETP region together with local partners such as the Malpelo Foundation in Colombia, Pelagios Kakunja in Mexico and France, Osa Conservation in Costa Rica and Ecuador’s Ministry of Environment. These 2-3 week-long expeditions were mostly undertaken as part of the Pristine Seas efforts to explore, document and help safeguard some of the most pristine parts of our oceans. This research is also part of ongoing efforts by CDF to strengthen science-based conservation across the Eastern Tropical Pacific. 

Currently, less than 10% of the ocean is in some form of protection — and only 3% is highly protected from damaging activities. An overwhelming body of peer-reviewed research shows that MPAs that ban fishing are the most effective mechanism to replenish marine life and deliver countless benefits to people, the economy and the climate. 

“We only have five years left to achieve the global goal of protecting 30% of the ocean by 2030, with research showing we must establish 300 large, remote MPAs and 190,000 smaller, coastal MPAs to achieve the target,” said Sala. “The success of the remote island MPAs of the Eastern Pacific Ocean serve as inspiration to us all.” 

This research was made possible thanks to the financial support of the Save Our Seas Foundation, the Mark Rohr Foundation, the Darwin and Wolf Conservation Fund, MAC3 Impact Philanthropies, Rolex Perpetual Planet, Sven Lindblad and National Geographic Pristine Seas donors.

For over 65 years, the Charles Darwin Foundation has worked in close partnership with the Galapagos National Park Directorate to conduct scientific research that supports conservation and the sustainable management of the Galapagos Islands—one of the world’s most extraordinary natural laboratories. Today, CDF is actively working as part of the CMAR network (Eastern Tropical Pacific Marine Corridor) to create a safe corridor for migratory species to roam freely throughout the region.

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About the Charles Darwin Foundation 

The Charles Darwin Foundation for the Galápagos Islands (CDF) is an international non-profit organization that has operated in Galapagos since 1959 under a special agreement with the Government of Ecuador. Its mission, and that of its Research Station, is to address the greatest threats and challenges facing Galapagos through scientific research and conservation actions, to protect one of the world’s most important natural treasures. Today CDF supports more than 25 research, conservation, and education projects across land and sea, and is the custodian of over 137,000 specimens in its Natural History Collections. Its diverse team of more than 140 scientists, educators, and support staff is composed primarily of Ecuadorian citizens, with over 60% from Galápagos. For more information, please visit: www.darwinfoundation.org 

About National Geographic Pristine Seas 

National Geographic Pristine Seas works with Indigenous and local communities, governments, and other partners to protect vital places in the ocean through research, policy, and filmmaking. Since 2008, Pristine Seas has helped establish 31 marine protected areas, 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.