July 31, 2026 — An intensifying El Niño is forecast to make it “a sharky summer” off the California coast, with greater numbers of white sharks arriving with warmer waters from the south, but they are far from the only marine life expected to make surprise visits.
Strong El Niños can move several species of sharks, as well as rays, tropical fish, birds and even sea snakes northward into waters where they rarely appear.
“We expect to see all kinds of weird tropical things come up with this warm water,” said Douglas McCauley, director of the Benioff Ocean Initiative at the University of California, Santa Barbara.
The strongest El Niños – and this one is forecast to be among the very strongest – can alter entire marine ecosystems, shifting both animals and the food they need to survive.
Its ripple effects in winds, rain and ocean currents can extend across the world’s oceans. Studies have linked El Niño and its cooler water counterpart – La Niña – to starving sea lions in Peru, changes in sea turtle behaviors in the Caribbean and fisheries successes in the Amazon and Congo rivers.
El Niño can trigger “a lot of animal movement,” said Nate Jaros, a vice president of animal care at the Aquarium of the Pacific.
This summer, juvenile sharks and other aquatic visitors are turning up early, thanks to the effects of an intense marine heat wave already in place before El Niño arrives, McCauley said.
“We’re already seeing Mahi mahi. You’ll see more bluefin tuna, and you see weird stuff, like we’ll see more sea turtles and sea snakes,” McCauley said.