Sea Turtles of the World: Olive Ridleys

Meet the Olive Ridley

The olive ridley is the most abundant sea turtle in the world, and the one with the most dramatic way of nesting. In places like La Escobilla in Mexico, Ostional in Costa Rica and the Odisha coast of India, tens of thousands of females can arrive on the same beach within a few days in a mass event called an arribada. She is named for the olive color of her shell, and the word “ridley” is a bit of a mystery, because nobody is sure where it came from. She is a small, hardy turtle, roughly two feet long and around 100 pounds, and she nests in about 40 countries across the Atlantic, Pacific and Indian oceans.

Think of her as the Kemp’s ridley’s slightly taller cousin. Her heart-shaped shell is a bit more domed, her color runs from olive to gray-green, her head is triangular, and her belly is a pale cream. What gives her away is the plate count, because she usually has six to nine pairs of plates down each side of her shell, sometimes uneven from one side to the other, while a Kemp’s has five. NOAA’s olive ridley page has more. Her whole identity is the crowd, and that changes everything about the beach she needs.

The Sand for the Olive Ridley

The olive ridley is, by sheer population, the most abundant sea turtle on Earth. She’s also the cousin of the Kemp’s ridley, sharing that same rare arribada instinct, coming ashore in mass synchronized waves instead of alone in the dark. But her arribadas happen on a scale nothing else in this series comes close to, so many females on the same small stretch of sand at once that later arrivals routinely dig up the nests laid hours before by turtles just like them. It’s the strangest paradox in the whole animal kingdom to me, a species so successful in raw numbers that success itself becomes one of her biggest threats.

Arribada beaches tend to be open, moderately sloped, and relatively wide, nothing as particular as a leatherback’s steep drop-off or a hawksbill’s hidden vegetation. What actually defines an olive ridley beach isn’t the sand itself so much as the sheer scale of what happens on it. A handful of specific beaches around the world have become the gathering points for hundreds of thousands of turtles at once, an instinct scientists still can’t fully explain, and once a beach earns that reputation, it keeps drawing them back, generation after generation, density compounding on density.

Costa Rica’s Working Beach

Ostional, on Costa Rica’s northwest Pacific coast, is an 8-kilometer stretch of sand roughly 200 meters wide, and it’s home to something no other beach on this list can claim, a fully legal, government-regulated egg harvest run by the local community. The logic behind it is almost mathematical. Nest density here gets so extreme, sometimes 11 nests per square meter, that later-arriving females destroy a huge share of the eggs laid by turtles just ahead of them anyway. So since 1987, the village of Ostional has been permitted to harvest a portion of those doomed eggs during the first days of each arribada, sell them legally, and in exchange keep the beach clean and patrol it against poachers and predators for the rest of the season. It’s not how conservation usually works. It’s also, by most measures, working.

Mexico’s Surfing Turtles

La Escobilla, on the Oaxaca coast near Puerto Escondido, hosts the largest olive ridley arribada on the planet, more than 300,000 females in a single event some seasons, over a million nests across a full year in the biggest years on record. Visitors who’ve stood on this beach during an arribada describe what looks, from a distance, like the sand itself has turned to boulders, thousands of turtles packed shoulder to shoulder as far as the eye can see. The surf here comes in hard, head-high waves crashing straight onto the beach, and the turtles ride those same waves in, which makes the whole approach look uncannily like a lineup of surfers waiting to be waved ashore.

India’s River-Mouth Rookeries

Odisha, on India’s eastern coast, holds the largest known olive ridley rookery in the world at Gahirmatha, a barrier beach in front of the Bhitarkanika mangroves where the Brahmani and Baitarani rivers meet the Bay of Bengal. Gahirmatha itself is a strictly protected sanctuary, but nearby Rushikulya, where the river of the same name reaches the sea, has become the more accessible place to actually witness an arribada, sometimes drawing over 600,000 nesting females across a single event. The sand along this whole stretch is soft and gently sloped, exactly the kind of low-disturbance shoreline the species needs, though offshore trawling remains enough of a threat that the Indian Coast Guard runs a dedicated seasonal patrol, Operation Olivia, specifically to protect turtles migrating toward these beaches.

Her Track and the Crowded Beach

She’s one of the two smallest sea turtle species, with a heart-shaped, olive-green shell and a crawl that’s easy to lose track of in the chaos of an arribada, since there are simply so many tracks overlapping at once that individual trails blur together. A clutch runs 100 to 150 ping-pong-ball-sized eggs, and unlike almost every other species in this series, her biggest threat to nest survival on an arribada beach isn’t a predator at all. It’s the next wave of turtles just like her, coming ashore an hour later and digging in the exact same crowded stretch of sand.

Florida’s Lone Visitor

And then there’s Tini. In May of 2026, researchers at Loggerhead Marinelife Center watched a small, unfamiliar turtle come ashore on Jupiter Beach and do something no olive ridley had ever documented doing in Florida, nest completely alone, thousands of miles outside her usual range, on a beach built for loggerheads, greens, and leatherbacks instead. Genetic testing confirmed her species. Nobody fully knows why she was there, though warming ocean temperatures pushing the species’ range northward is the leading theory. Every other beach in this piece involves hundreds of thousands of her. Tini’s nest involved exactly one.

Country by Country: Everywhere She Nests and Feeds

The olive ridley is the most widespread sea turtle on this list, and the one with two completely different ways of nesting. NOAA says she has documented solitary nesting in roughly 40 countries, plus a few famous beaches where tens of thousands arrive together. I’ve sorted this by ocean, with the arribada beaches marked, and the feeding side after. Numbers are snapshots, and some populations have fallen sharply, which I’ve noted.

The Eastern Pacific

• Mexico: La Escobilla in Oaxaca, one of the great arribada beaches, along with Chacahua, Mazunte and sanctuary beaches in Guerrero and Chiapas.
• Costa Rica: Ostional and Nancite, the two big arribada beaches in Guanacaste, plus Camaronal and smaller beaches on the Osa Peninsula.
• Nicaragua: La Flor and Chacocente, both arribada beaches, plus San Juan del Sur.
• Panama: Isla Canas and Playa La Marinera on the Azuero Peninsula, one of the few arribada beaches in the world.
• Guatemala, El Salvador and Honduras: solitary nesting on the Pacific coast, with olive ridleys making up more than 99 percent of Guatemala’s nesting at Monterrico-Hawaii.
• Colombia: hatchling releases near Bahia Solano in Choco, and olive ridleys among the species recorded at Gorgona Island.

The Atlantic and the Caribbean

• Brazil: a large solitary nesting population, centered on Sergipe and Bahia.
• Suriname and French Guiana: small-scale arribadas. Suriname’s numbers fell by more than 90 percent since 1967.
• Guyana: minor nesting.
• Gabon: the largest known olive ridley nesting population in the eastern Atlantic, estimated at 1,000 to 5,000 breeding females a year by NOAA.
• Angola: the surprise. A 2022 study of seven monitored sites called it the largest non-arribada population in the world.
• Republic of the Congo: nesting recorded.
• Trinidad and Tobago and Curacao: occasional nests, with a few other southern Caribbean islands.
• United States: Florida logged its first confirmed olive ridley nest on Jupiter Beach in 2026.

Olive ridleys feed along the coasts of West Africa and northern South America.

The Indian Ocean and South Asia

• India: Odisha, with the arribada beaches at Gahirmatha, the Devi River mouth and Rushikulya (more than 100,000 nests a year in the NOAA figure), plus a newly discovered mass-nesting site in the Andaman Islands with more than 5,000 nests in a season. Solitary nesting also runs down much of the mainland coast, including Tamil Nadu, Andhra Pradesh, Kerala, Karnataka, Maharashtra, Gujarat, West Bengal and Goa, plus Lakshadweep.
• Sri Lanka, Bangladesh and Pakistan: all list olive ridleys as a nesting species.
• Myanmar: solitary nesting, in decline.
• Thailand: the Andaman coast, in October to February, and declining.

Southeast Asia

The Southeast Asia review gives the following.

• Indonesia: Alas Purwo National Park in East Java, with about 1,100 clutches in 2018.
• The Philippines: La Union, Palawan, Zambales, Bataan and Cavite, with La Union’s CURMA project having released more than 200,000 hatchlings.
• Brunei: the northern coast of Borneo, the island’s only substantial olive ridley rookery.
• Malaysia: Terengganu once held thousands of nests, and the review counts fewer than 5 clutches a year now.
• Timor-Leste: olive ridley nests are among the ones rescued at Lenuk Tasi.
• Vietnam: olive ridleys haven’t been recorded nesting there for more than a decade.

Where She Feeds

The olive ridley spends most of her life in open ocean. In the eastern Pacific, she ranges from southern California to northern Chile. Turtles from Costa Rica’s nesting beaches migrate across the deep Pacific. Across the tropical Atlantic, Pacific and Indian oceans, she is widespread and mostly pelagic.

The northernmost beach she has reached recently is on the California coast. In September 2026, NOAA reported what appears to be the first confirmed olive ridley nesting on the U.S. West Coast, at Seal Beach and Huntington Beach, which is a good reminder that range maps are always a little behind the turtles.

Where You Can Go Stand on That Sand

Ostional Wildlife Refuge welcomes visitors during arribadas, with the community’s own guides explaining the harvest program alongside the nesting itself. La Escobilla runs regular evening tours out of Puerto Escondido, often paired with a hatchling release at sunset before the adults come ashore after dark. In Odisha, Rushikulya is the more visitor-accessible of India’s major rookeries, with Gahirmatha’s protected status keeping it more research site than tourist destination. And if you happen to be walking Jupiter Beach, Florida, on the right night, you’re not likely to see another olive ridley anytime soon, but you’ll be walking the exact stretch of sand where one already made history.

Thoughts & Reflections