In August 2023, something unusual happened off the coast of San Diego. As Tropical Storm Hilary — the first tropical storm to hit Southern California in over a hundred years — battered the region with fierce winds and record rainfall, a group of young great white sharks made a surprising choice: they fled their favorite hangout spot and headed for safer waters.
Scientists at UC San Diego's Scripps Institution of Oceanography and the Shark Lab at California State University, Long Beach were already watching. They had tagged 22 juvenile white sharks — 13 females and 9 males — with tiny acoustic transmitters that let them track every move. Underwater receivers recorded more than 524,000 pings from these sharks before, during, and after the storm.
Before Hilary arrived, researchers spotted 16 to 19 tagged sharks per hour in their usual nursery area near Torrey Pines and Del Mar — shallow, warm waters where young white sharks spend their first years eating stingrays and small fish, safe from bigger predators. But during the storm on August 20, 2023, that number dropped by roughly half. Only about eight sharks stayed in the nursery at any given time.
The sharks didn't go far. Researchers noticed a spike in detections at La Jolla Cove, a spot next to a deep underwater canyon that offered protection from the storm's powerful winds. One shark equipped with a pressure sensor was recorded diving to 433 feet deep — the deepest dive recorded during the entire study. The scientists think the shark was trying to escape the rough conditions near the surface.
"We believe this more sheltered habitat may have served as an important nearshore refuge for some individuals," said Jack Elstner, a Ph.D. student at Scripps and the study's lead author.
The good news? Nearly every shark came back. Most returned within just a few days, and within three weeks, almost the entire group was home. Only one shark left during the storm and was never detected again in San Diego that year.
"To our knowledge, this is the first study to document storm-response behavior in white sharks," Elstner said. The findings, published in the journal Movement Ecology, offer a rare glimpse into how these powerful predators handle extreme weather — and suggest they may be more adaptable than we thought.
Chris Lowe, who leads the Shark Lab at CSULB and co-authored the study, said the varied responses were telling. "The fact that some sharks 'tucked' into the less wave-active La Jolla Cove during the storm was an interesting finding," he noted. "Not all sharks did the same things."
For scientists studying white sharks — a species still recovering from decades of overfishing — understanding how they respond to storms matters more than ever. As climate change brings more extreme weather to coastlines around the world, these young sharks are proving they can find creative ways to ride out the chaos.