NOAA documents first olive ridley sea turtle nestings on California coast

Scientists question whether warmer Pacific waters drove shift northward

Two separate olive ridley sea turtles laid eggs on Orange County beaches in Southern California within a week in mid-September 2026 — the first recorded nesting of the species on the US west coast, according to Justin Viezbicke, the California stranding coordinator for the National Oceanic and Atmospheric Administration. The first turtle came ashore on Seal Beach on September 16, and a second followed on Huntington Beach the following weekend, with local officials fencing off both sites for protection.

The discovery lands during an unusually active stretch in the Pacific Ocean, raising questions about whether the turtles’ presence signals a lasting northward shift driven by warming waters or a one-off displacement from recent hurricane activity.

Initial news reports suggested that a single female turtle had laid both clutches, but scientists who compared photographs of the animals’ shell shapes and barnacle patterns determined the two nestings involved separate females, Viezbicke said. “This is the first documented case of a turtle nesting on the west coast,” he said.

Olive ridley turtles typically lay their eggs on beaches much further to the south, in Mexico and Central America, Viezbicke said. What brought the turtles north is “the million dollar question,” he said, with scientists weighing several possibilities: warmer coastal waters, broader El Niño effects, or whether the animals “could have been blown off course by the recent hurricane.” “There’s been a lot of activity in the Pacific Ocean,” he added.

Lance Adams, an aquarium veterinarian at the Aquarium of the Pacific in Long Beach, said the nestings could “herald a broader northward shift in the olive ridley turtle’s nesting patterns, one driven by climate crisis and the warming ocean waters in the turtles’ native nesting areas.”

The sex of olive ridley turtles is determined by incubation temperature, Adams said, and “after about 87.8F, they’re almost all female.” A skewed sex ratio could pressure the species to seek cooler nesting grounds, he noted.

Adams cautioned against drawing broad conclusions from two sightings. “The turtles could be here by mistake,” he said. Because individual olive ridleys typically lay multiple nests in a season, “we might see additional sea turtles making beach crawls to nest in the next 30 to 90 days,” Adams added.

The two nests have been surrounded by protective fencing, but local officials can do only so much. Eggs typically take 45 to 60 days to hatch, Viezbicke said, leaving them exposed to predators such as coyotes, human interference, and incoming hurricane swells and high tides expected as soon as the following Monday — weather that Viezbicke said could wash away the nesting beach.

Californians who encounter nesting turtles are advised to stay at least 50 feet away and not interfere, Adams said. Sightings should be reported to a lifeguard or to NOAA’s marine animal stranding hotline. Approaching fenced nesting sites will not offer a closer view, Adams added: “People won’t see anything.” Those who want to observe live sea turtles in action can visit rescued animals on display in rehabilitation tanks at an aquarium, he said.

Warmer Pacific temperatures have produced a broader pattern of unusual marine life sightings along the California coast, Viezbicke noted, including shark species not normally present, rays, seahorses, and the venomous yellow-bellied sea snake. Adams said the public should adapt to shifting wildlife patterns and keep their distance from unfamiliar species. “Turtles aren’t particularly dangerous to humans,” he said. “They can bite. They can slap with their flippers. Someone could potentially get hurt, but probably not seriously.”

Olive ridley sea turtles are one of the most abundant turtle species worldwide, but are protected under the US Endangered Species Act.