Sea turtles nested on a U.S. West Coast beach for the first time on record

Two olive ridley sea turtles came ashore in Orange County, California, in September 2026 and laid eggs, and NOAA Fisheries says the nests are without precedent. “This is the first-ever recorded nest for any sea turtle species on the U.S. West Coast,” the agency wrote in a feature story published September 25. The first turtle nested near Seal Beach on September 16; a second followed near the Huntington Beach Pier three days later.

By the time the agency announced the nests, between 100 and 200 eggs from the two clutches had already been moved indoors. Biologists and partner agencies had decided the beach was too exposed, and the eggs now sit in an aquarium incubator rather than in sand.

Two nests, eight miles apart, two different turtles

The question NOAA’s scientists had to settle early was whether one turtle had nested twice or two turtles had nested once each. Dr. Cali Turner Tomaszewicz, a research biologist in the Marine Mammal and Turtle Division of NOAA’s Southwest Fisheries Science Center, compared photographs of the two animals. She looked at body shape, the number and location of barnacles, and each turtle’s scute pattern, the arrangement of the large scales on the shell, and concluded they were distinct individuals, according to NOAA Fisheries’ account of the nesting. The two sites are roughly eight miles apart.

That distinction matters because olive ridleys normally nest two or three times a season, about two weeks apart. NOAA notes that each of the two females could therefore return to the same coast again, and beach monitoring is continuing for any further nesting. The agency’s photo gallery of the event, last updated October 2, shows a protective fence around a nest, with credit to the Huntington Beach Fire Department and the U.S. Navy.

Olive ridleys and why California is far from their usual range

Olive ridleys are among the smallest sea turtles. NOAA’s species profile puts adults at two to two and a half feet long and up to 100 pounds, and describes mass nestings called arribadas, in which thousands of females, sometimes tens of thousands, emerge on the same beach together. Under the Endangered Species Act, the breeding populations on Mexico’s Pacific coast are listed as endangered and all other populations as threatened.

The nearest documented nesting is in the Western Cape region of Baja California, Mexico, near Todos Santos, where the season runs from July to December. Adult females show strong site fidelity, returning roughly 15 years after hatching to the beaches where they were born, which is why a nest in Southern California was not something the NOAA team had planned for. The four species NOAA’s Southwest Fisheries Science Center turtle program tracks off California are green, loggerhead, hawksbill and leatherback turtles; olive ridleys are not on that list.

Marine heatwaves, an El Niño and a navigational slip

NOAA does not claim to know why the turtles came north. The agency points to warm sea surface temperatures from marine heatwaves and an incoming 2027 El Niño as likely contributors, alongside the species’ nomadic habits and the chance that the animals simply made navigational errors. That is a list of candidate explanations, not a finding, and the feature story presents it that way.

The nesting also overlapped with a storm. LAist reported that about 200 eggs were evacuated on Friday, September 25, as Hurricane Polo threatened the coast with powerful waves. They went to the Molina Animal Care Center at the Aquarium of the Pacific in Long Beach, where temperature-controlled containers are meant to mimic a sandy nest. NOAA describes the transfer as made “out of an abundance of caution.”

Hatching window and what NOAA plans next

Incubation typically lasts 45 to 60 days, which puts any hatching in early to mid November, counted from the September nesting dates, if the eggs survive the move. LAist, citing the aquarium, gave the same window and said hatching would likely come around early November. If they hatch, the plan described by NOAA is to release the hatchlings on the beaches where the nests were laid, so the young turtles start life on the sand their mothers chose. Aquarium of the Pacific president Jeff Flocken told LAist that people “will need to adapt and make space” so endangered and threatened species have a fighting chance as animals adapt in unexpected ways.

Among the named partners on the NOAA story are the U.S. Fish and Wildlife Service, the cities of Huntington Beach and Seal Beach, the Aquarium of the Pacific, the U.S. Navy, the California Department of Fish and Wildlife, the Bolsa Chica Ecological Reserve, California State University, Long Beach, and the Surfside Colony Community Organization. NOAA says it will continue interagency coordination and public outreach as the incubation runs its course, and whether any of the eggs hatch is the next fact the agency has yet to report.

This article was produced with the assistance of AI and reviewed by Morning Overview editors prior to publication.

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