Rising ocean temperatures and intensifying El Niño conditions are pushing unusual marine species, including white sharks, blacktip sharks, and venomous sea snakes, into northern coastal waters across the United States, scientists reported on July 31, 2026.
The rapid shift in ocean currents and water temperatures is suppressing upwelling along the Pacific coast, forcing marine predators and prey to migrate beyond their typical ranges toward cooler regions.
According to researchers at the Benioff Ocean Initiative at the University of California, Santa Barbara, a pre-existing marine heat wave combined with El Niño has accelerated the arrival of tropical species in California waters.
“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.
McCauley noted that species such as mahi-mahi, bluefin tuna, sea turtles, and highly toxic yellow-bellied sea snakes are appearing far north of their traditional habitats.
“Some of these kinds of interesting oddities that are never a part of California will become part of this temporarily tropical El Niño-heated California,” McCauley said.
Shifting Prey and Predators
Research from Long Beach State University's Shark Lab indicates that reduced upwelling disrupts the supply of zooplankton and small fish, pushing prey species like squid, anchovies, and sardines northward.
“We get this whole different ocean,” said Chris Lowe, a professor of marine biology and director of the Shark Lab.
Lowe explained that warmer ocean conditions attract brown stingrays, which in turn draw juvenile white sharks closer to populated shorelines.
“When I say this is going to be a sharky summer, what I should also say is it’s going to be a stingray summer as well, and we’re probably going to have record numbers of stingray injuries to people,” Lowe said.
Along the Atlantic coast, researchers from Florida Atlantic University observed similar distributional shifts, tracking blacktip sharks further north toward Long Island, New York.
“They are just like us.
They like our air-conditioned temperature,” said Dr. Stephen Kajiura, a Florida Atlantic University professor who has studied blacktip sharks for about 15 years.
Kajiura pointed out that water temperatures around 72 degrees Fahrenheit create ideal conditions for blacktip shark migration.
“Our room temperature is 72 or so. [That's] the perfect temperature for these blacktip sharks,” Kajiura said.
Because blacktip sharks travel within 50 meters of the shoreline, researchers emphasized that they frequently overlap with human recreational zones.
“These are the ones that are in close proximity to the surfers and the swimmers,” Kajiura said. “That's the species that's most likely to have encounters with people.”
A recent study in the Journal of Coastal Research also indicated that beach nourishment projects create murky water, which may alter shark hunting patterns and increase accidental encounters.
“What’s striking is how closely the distribution of blacktip sharks overlaps with areas impacted by turbidity events,” Kajiura said in a Florida Atlantic University news release.
Despite the changing migration patterns, Kajiura maintained that actual shark attacks remain extremely rare.
“The chances of you having a negative encounter with a shark are so minuscule,” Kajiura said.
“Don't let that diminish your ability to take advantage of the beautiful beaches we have here in Florida.”
Historical data from the California Department of Fish and Wildlife shows only 236 documented shark-human interactions off the California coast since 1950, set against more than 120 million annual beach visits.
During a previous El Niño event, kayakers reported encountering hammerhead sharks off the coast of Southern California.
“We saw this fin and then it dove,” kayaker Kyle Hudgins told KNBC after his friend Dylan Marks was bitten while kayaking near Santa Monica.
Hudgins described the moment the bite occurred while they were on the water.
“We didn't see it for like five minutes and then all of a sudden he had his foot over the side and he just got bit.
And then he put his foot up on the kayak and he said, 'Oh, dude. I just got bit!'”
Hudgins recalled.
Medical professionals recommend standard safety measures for beachgoers to lower risks further, such as removing shiny jewelry, avoiding open wounds in the water, and exiting immediately if a shark is spotted.
