Revillagigedo Archipelago · Mexican Pacific · Whale Research
North America's
Whale Nursery
Four volcanic islands far off the coast of Mexico shelter one of the most important humpback breeding grounds in the North Pacific. Sea Shepherd crews have worked alongside Mexican scientists to study the whales that return every winter.
- Square miles of fully protected ocean, nearly
- 58,000
- Miles southwest of Cabo San Lucas
- 240
- Volcanic islands in the archipelago
- 4
Sea Shepherd / The Archipelago
A Pristine Laboratory
Socorro, Clarion, San Benedicto and Roca Partida rise from the Pacific in one of the most productive marine ecosystems on Earth.
The Revillagigedo Archipelago was named a UNESCO World Heritage Site in 2016 and is now home to the largest fully protected marine area in North America. From late January to late March, humpback whales gather here to breed, give birth and nurse their young.
Working with CONANP, Mexico's park service, and whale scientists from the Universidad Autonoma de Baja California Sur, Sea Shepherd has supported research seasons here that track the health, behavior and survival of the whales that winter in these waters.
Fully protectedCommercial fishing, oil and gas extraction and tourism development are banned across the national park.
A humpback mother and calf off Socorro Island. Credit: Simon Ager / Sea Shepherd
National park · Mexican Pacific
Revillagigedo
Nearly 58,000 square miles of ocean around four islands, home to more than 37 species of sharks and rays and at least 366 kinds of fish.
Largest island · Research base
Socorro Island
Socorro, the largest island, has been the anchorage for our research seasons in the archipelago.
Sea Shepherd / Wildlife
What Lives Here
- 01
Humpback whales
Mothers give birth and nurse their calves in the shelter of the islands before the long migration north.
- 02
Giant mantas
Pacific giant mantas glide over the pinnacles and often circle divers with open curiosity.
- 03
Sharks and rays
More than 37 species of sharks and rays live in the park, from silky sharks to oceanic mantas.
- 04
Dolphins and reef fish
Bottlenose dolphins patrol the bays, and dozens of the fish species here are found nowhere else on Earth.
- 05
Seabirds and turtles
Near-threatened Laysan albatross nest on the islands, and four species of sea turtle feed in the surrounding waters.
Sea Shepherd / The Research
How the Science Works
Each season brings scientists, park rangers and crew together for weeks of methodical fieldwork far from the nearest port.
Whale surveys
Crews log every group of whales they find, with its size, behavior and calves.
Photo identification
Photos of tail flukes and dorsal fins identify individual whales as they return season after season.
Health and song
Small skin samples reveal genetics, stress and contaminants, while hydrophones record the season's song.
Reef and dive surveys
Divers count fish, corals and invertebrates across the park, giving CONANP data for its decisions.
Sea Shepherd / The Threat
What Threatens It
- 01
Illegal fishing
The park is vast and remote. Under Operation Treasured Islands we use satellite monitoring with SkyTruth to spot vessels fishing where they should not.
- 02
Bycatch at the edges
In 2020 our freedivers and a CONANP ranger met a silky shark still carrying a longline hook. Silky sharks are the most common shark bycatch in eastern Pacific tuna fisheries.
- 03
Distance
Hundreds of miles from the mainland, the islands are hard to patrol. CONANP rangers watch the park year round, and every extra vessel out here makes a difference.
- 04
Busy waters elsewhere
Researchers compare calves here with those near Los Cabos, where heavy boat traffic shapes a very different life for mothers and young.
Sea Shepherd / Results
Building the Record
Years of fieldwork in one of the last truly protected corners of the Pacific.
-
2016 UNESCO
WorldHeritage
status for the archipelago, recognizing it as one of the richest marine ecosystems on Earth.
-
2017 Mexico
58,000sq mi
protected as a no-take national park, the largest fully protected ocean area in North America.
-
2021 CONANP and UABCS
5th season
of the research partnership, studying the health and behavior of humpbacks and other marine mammals.
-
2025 SocorroLatest
Backon site
Our crews returned to the islands to document the whales, dolphins and sharks of the park.
Sea Shepherd / Gallery
From the Archipelago
Sea Shepherd / Revillagigedo
Defend the Whale Nursery
Research seasons this far offshore take fuel, a skilled crew and scientists on board. Your gift keeps our crews working in Mexico's most important marine protected areas.
58,000 square miles of protected ocean
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