Surfers, swimmers and waders in Southern California have been unwittingly sharing the water with great white sharks more often than they likely realize, according to a new study published last week in the journal Plos One.
At two popular beaches, sharks and people swam together 97 percent of the time, the researchers found.
Though that statistic might make some swimmers want to stick to the beach, the study’s authors say the findings should actually reassure outdoor adventurers that sharks pose a low risk to humans, per the Los Angeles Times’ Christian Martinez. Despite what movies like Jaws have led beach-goers to believe, sharks tend to “mind their own business,” as study co-author Patrick Rex, a marine biologist in the “Shark Lab” at California State University, Long Beach (CSULB), tells the publication.
“People think, ‘If I see a shark … I’m going to get bitten, or I’m in danger,’” he says to the L.A. Times. “And what we’ve seen is that that’s not necessarily the case.”
The findings also revealed that sharks are swimming a lot closer to the beach than previously thought—instead of miles out, they may be within 50 to 100 yards of where the waves break, or even closer.
To understand great white shark behavior along the coast, researchers flew drones over 26 beaches in Southern California from January 2019 to March 2021. They analyzed more than 700 hours of video footage, making note of where and when waders, surfers, swimmers and stand-up paddle boarders were recreating. They also recorded observations of individual sharks, then compared the sightings to get a sense of the human-shark distribution.
Two areas stood out: one in southern Santa Barbara County, and another in central San Diego County. In these so-called “aggregation sites,” or nursery habitats, the researchers noted a big overlap between water users and sharks—and in particular, juvenile white sharks. Those young creatures like to hang out near the beach to feed on fish, squid and stingrays, as well as bask in the warmer water temperatures and enjoy some protection from predators like orcas, adult white sharks and large mako sharks.
Though the researchers could clearly see sharks and humans in close proximity to one another in the footage, the humans likely had no idea the fish were nearby, per the Sacramento Bee’s David Caraccio. To understand the full implications of this overlap, researchers also dug into shark bite data. They found just one reported incident during the two-year survey period in Southern California, and in that case, the swimmer could not identify the marine animal that bit her. More broadly, they found evidence of just 20 unprovoked white shark bites in the region since 2000.
Conservation efforts have allowed white sharks to flourish along California’s coast. And because of rising temperatures from human-caused climate change, more humans are likely heading to the beach to cool off. Despite these converging trends, the researchers found “little evidence of increased frequency shark bites on humans in southern California,” they write in the paper.
Even so, lifeguards up and down Southern California’s coast may want to use the study’s findings to help inform their approach, per the paper—the researchers expect the shark aggregation sites to change in the future.
“These sharks are highly mobile—they can always be at your beach—but rest assured, the data that we’re getting now indicates that as long as you’re not bothering them, they won’t bother you,” says study co-author Chris Lowe, a marine biologist and the director of CSULB’s Shark Lab, to KTLA’s Cindy Von Quednow.