In a development that has delighted marine biologists and confused everyone else, a female olive ridley sea turtle crawled out of the surf in southern California last weekend around sunset and began laying eggs in the sand. Witnesses on Huntington Beach were shocked and excited, presumably because they had planned on a normal beach day and not a front-row seat to evolutionary history.

According to Justin Viezbicke, the California stranding coordinator for the National Oceanic and Atmospheric Association (Noaa), "This is the first documented case of a turtle nesting on the west coast." What makes it even more remarkable is that two different olive ridley sea turtles were identified laying eggs on Orange county beaches in the last week - the first on Seal Beach, the second on Huntington Beach. Scientists are now debating whether this is a freak occurrence or the beginning of a lasting trend, which is science-speak for "we have absolutely no idea yet."

Early news reports suggested a single female turtle laid eggs on both beaches, but scientists analyzed photographs of the turtles' shell shapes and barnacle patterns and determined that two separate olive ridley turtles had begun nesting on the US coast. Yes, barnacle patterns - nature's fingerprinting system, apparently.

Olive ridley turtles typically lay their eggs much further south, in Mexico and Central America, so their sudden appearance in California is what Viezbicke calls the "million dollar question." Scientists are examining several theories: warmer coastal waters, effects of El Niño, or the possibility that the turtles "could have been blown off course by the recent hurricane." As Viezbicke noted, "There's been a lot of activity in the Pacific Ocean," which is one way to describe a hurricane season that has apparently turned turtles into accidental tourists.

While it's too soon to tell, Lance Adams, an aquarium veterinarian at the Aquarium of the Pacific in Long Beach, says these first recorded US coastal nests could signal a broader northward shift in the olive ridley turtle's nesting patterns, driven by climate crisis and warming ocean waters in their native nesting areas. The sex of olive ridley turtles is determined by temperatures where the eggs hatch, and warmer temperatures produce more female turtles. "After about 87.8F, they're almost all female," Adams said. To achieve a balanced population, the sea turtles might need access to cooler nesting areas - which is either an argument for climate action or a setup for a very specific romantic comedy.

On the other hand, Adams cautions against generalizing from just two sightings: "The turtles could be here by mistake." Because the nesting season isn't over and individual olive ridley turtles typically lay multiple nests of eggs, "We might see additional sea turtles making beach crawls to nest in the next 30 to 90 days," Adams said.

For protection, the new turtle nests have been surrounded by fencing. But local officials can only do so much to protect the eggs, which typically take 45 to 60 days to hatch. It's not just local predators like coyotes or interfering humans - new hurricane swells and high tides are expected as soon as Monday of next week, and there's a risk of the extreme weather "washing away that part of the beach." So the turtles have traded one set of dangers for another, which is a very on-brand 2023 storyline.

Californians who spot sea turtles on a local beach should not interfere with them and should keep at least 50 ft away, Adams advised. To report a new turtle sighting, tell a lifeguard or call Noaa's marine animal stranding hotline. Getting close to the turtles' fenced-off nesting spots is not a good idea, he said: "People won't see anything." If locals want to observe live sea turtles, they can visit rescued turtles on display in rehabilitation tanks at an aquarium - which is basically the turtle equivalent of watching a nature documentary from your couch.

Olive ridley sea turtles are one of the most abundant turtle species worldwide but are protected under the US Endangered Species Act. Warmer ocean temperatures have led to sightings of all kinds of sea creatures not typically spotted on the California coast, including different shark species, rays, sea horses, and the venomous yellow-bellied sea snake. Adams advises people to adapt to shifts in wildlife patterns and keep their distance, though new unexpected species present different potential risks. "Turtles aren't particularly dangerous to humans. They can bite. They can slap with their flippers. Someone could potentially get hurt, but probably not seriously," he said. So if you see a sea turtle on a California beach, admire it from afar, call the authorities, and maybe reconsider your beach vacation plans - the turtles have clearly claimed this territory.