Exotic species appear off California thanks to an unusually strong El Nino

• An unusually strong El Nino has brought tropical sea life to California, including longfin bigeye fish, whale sharks, hammerheads, flying fish and a yellow-bellied sea snake.
• The event has also caused harm, with stronger waves, sea level rise and beach erosion, and California has declared a state of emergency ahead of more winter effects.
• Some businesses are benefiting, with more tuna, wahoo and dorado catches, while experts warn kelp and less mobile species may suffer until conditions return to normal in 2027.

DANA POINT, California – The longfin bigeye fish was spotted in California for the first time in September, and the first sea turtles of any kind nested on California beaches. Meanwhile, a venomous yellow-bellied sea snake swam ashore as whale sharks and hammerheads cruised just off the coast.

Exotic species have been visiting California’s shores since an unusually strong El Nino weather phenomenon arrived in 2026. Occurring naturally every few years, El Nino brings warm ocean water farther north, and tropical species with it, providing California with a stunning visual display that has become ever more evident with the advent of drone and video technology.

“There’s kind of a buzz. Fishermen are loving it for sure. I’m as interested as anybody else. It’s strange times,” said Nate Jaros, vice-president of animal care at the Aquarium of the Pacific in Long Beach.

Other visitors include flying fish and manta rays.

California had already experienced an unusual marine heat wave just before its arrival.

The phenomenon in 2026 coincided with a string of hurricanes in the eastern Pacific, fuelling sea level rise and large waves that have destroyed homes and denuded some Southern California beaches of sand. Preparing for more effects to come this winter, California has declared a state of emergency.

But it has provided a bounty for businesses like Dana Wharf Sportfishing & Whale Watching. Co-owner Donna Kalez said anglers have pulled in 5,000 yellowfin tuna in 2026, compared to two a year ago. They are also landing wahoo and dorado, also known as mahi-mahi, a green fish with a blunt head giving it the profile of a bulldozer.

“Dorado is very exciting because they’re very acrobatic, so they jump out of the water. We catch them off kelp paddies, and it’s a thrill,” Kalez said.

Experts expect conditions to mostly return to normal after El Nino, a natural phenomenon predating human-caused climate change, passes in 2027. The greatest short-term harm may be to kelp, which thrives in colder waters and provides habitat for multiple species, experts say.

“It’s good for some sharks and probably bad for others,” said Chris Lowe, director of the Shark Lab at California State University, Long Beach. “For animals that can’t move, that’s a bigger problem, right? Most sharks that are highly mobile. They can simply move.”

The yellow-bellied sea snake may have venomous fangs but cannot swim like a large shark. When an apparently sick one swam ashore in Orange County in September, a beachgoer used a palm frond to lift it off the sand and drop it in the sea. Jaros said that based on cellphone video he had little doubt it was the yellow-bellied sea snake, Hydrophis platurus.

There have only been six or seven confirmed sightings in California, said William Ludt, associate curator of ichthyology at the Natural History Museum of Los Angeles County. The last confirmed sighting came during the El Nino of 2015-2016, he said.

Exotic sharks such as the whale shark – a gentle giant and the largest fish on Earth – and the more menacing-looking hammerheads venture into California waters during El Nino. Both have been spotted recently. Lowe said a white shark nursery reappeared for the first time since 2011 in Santa Monica Bay, where juveniles frolic without bothering humans.

Ludt said the aptly named longfin bigeye fish species was recorded for the first time in California in 2026 when an angler caught one on the Venice Fishing Pier in Los Angeles.

When two olive ridley sea turtle nests were found on a pair of Orange County beaches in September, they marked the first-ever recorded nest for any sea turtle species on the US West Coast, according to the US National Oceanic and Atmospheric Administration.

The first was discovered by a beachgoer in Seal Beach on Sept 16, the second by lifeguards in neighbouring Huntington Beach three days later, officials said.

And other new species may yet arrive.

“We still aren’t fully through it,” Ludt said. “It’s still very much ongoing.” REUTERS