Juvenile great white sharks started appearing off California in February this year — two months earlier than the usual April arrival — and researchers say the state is heading into "one of its sharkiest summers in a decade" [1]. The driver is El Nino, which the National Oceanic and Atmospheric Administration confirmed formed in the Pacific in early June, warming the waters off Mexico and pushing cold-water species north [1].
"We started seeing baby white sharks in February, which we've never seen before," said Dr Chris Lowe, director of the Shark Lab at California State University Long Beach, whose team has tagged juvenile whites for 20 years [1]. Lowe points to 2015, an El Nino year that coincided with the marine heatwave known as the "Blob," when the lab counted "twice as many white sharks" along the coast. "When we have these El Nino conditions, it gets too warm, and the white sharks don't like it," he said. "And it pushes them into California" [1].
Where social clips and beach-closure posts turn each new sighting into evidence of sharply greater personal danger, the state's own experts frame the risk differently: the specific hazard this summer is fishing gear, not swimming. California passed emergency regulations last month barring certain gear at beaches and piers to stop accidental hooking of white sharks, which are fully protected and illegal to catch [1]. John Ugoretz, a pelagic fisheries manager at the California Department of Fish and Wildlife, said the concern is "the potential for a hooked shark to wrap the line around a swimmer, or even in a worse case, biting someone while it's fighting on that line" [1]. Lowe describes a shark snared on a metal line as potentially "like a cheese cutter" [1].
That reframes the useful record. Ugoretz reported "a pretty significant increase in people interacting with those white sharks in southern California," including people fishing for them [1] — an enforcement and behavior problem, distinct from the odds of an unprovoked bite. Those odds stay low: fewer than 250 shark incidents across all species in California since 1950, and just 17 fatal [1]. The animals move further north toward Santa Cruz and Monterey Bay in El Nino years and linger later, and Lowe expects hammerheads, bull sharks and tiger sharks to follow the subtropical fish [1]. More sharks, more overlap — but as both scientists stressed, larger aggregations have not translated into more bites. The number worth watching is whether hooking incidents fall under the new rules, not the size of the swarm.
-- Kenji Nakamura, Long Beach