Olive ridley sea turtles laid eggs on two Orange County beaches in mid-September, marking the first recorded natural sea turtle nesting anywhere on the U.S. West Coast.

The nesting sites sit roughly 10 miles down the coast from Newport Beach, in the same warm waters where yellow-bellied sea snakes turned up at Crystal Cove State Beach earlier this summer. NOAA Fisheries (the National Oceanic and Atmospheric Administration) confirmed the historic discovery on Tuesday, Sept. 22, after lifeguards found nests near Surfside, which borders Seal Beach, and south of the Huntington Beach Pier, as reported by the Daily Pilot.

Huntington Beach Marine Safety lifeguards found the first nest on Wednesday, Sept. 16, after responding to reports of a possibly injured turtle near Surfside. The turtle was not hurt. It was laying eggs.

A second nest appeared three days later, on Saturday, Sept. 19, near the Huntington Beach Pier. It remains unclear whether one turtle or two are responsible.

Trevor McDonald, Marine Safety Division chief with the Huntington Beach Fire Department, told the Daily Pilot that his lifeguards acted fast when they spotted the second turtle digging into the sand. "When our staff saw the turtle making a nesting spot, they immediately created a buffer zone to keep everybody back and keep the turtle safe and allow for the best chances of survival," McDonald said.

Each nest holds an estimated 50 to 100 eggs, according to ABC7. The eggs could take 45 to 60 days to hatch, putting a potential hatching window between late October and mid-November. Both sites are now fenced with protective barriers and interpretive signage.

Justin Viezbicke of NOAA Fisheries told ABC7 the turtle's behavior was unusual. Olive ridleys typically nest at night, but this one came ashore during the day and around sunset. Viezbicke also told ABC7 that additional undiscovered nests are possible.

Olive ridleys are the smallest sea turtle species. Adults weigh up to 100 pounds and grow 2.5 to 3 feet long.

Their major Pacific nesting grounds span Mexico, Nicaragua, Costa Rica and Panama. While olive ridleys occasionally follow warm currents into Southern California waters, NOAA said the species had never been documented nesting in the United States before.

The OC Register reported the nesting fits a broader pattern of tropical marine species appearing in Southern California as ocean temperatures linger in the mid-70s. Hammerhead sharks, a whale shark off San Clemente Island and sea snakes at Crystal Cove have all been spotted in Orange County waters in recent months.

Sea turtles are protected under the Endangered Species Act. Disturbing the animals or their nests can carry federal penalties.

NOAA asks beachgoers to give the nesting sites wide clearance. Anyone who spots a stranded sea turtle along the coast can call the NOAA Fisheries West Coast Stranding Hotline at (562) 506-4315.