A group of more than a dozen great white sharks were spotted swimming in the surf off a Southern California beach, but beachgoers shouldn't panic, say shark experts.
Moreover, the aggregating great whites actually demonstrate the ocean's health, experts said.
The great white sharks (Carcharodon carcharias) were spotted off Dana Point, a known hotspot for the species. On May 10, the sheriff's deputy called down from a helicopter on a loudspeaker to paddleboarders in the area to warn them of the shark sightings: "You are paddleboarding next to approximately 15 great white sharks," Deputy Brian Stockbridge, of the Orange County Sheriff's Department, said over the helicopter loudspeaker, as reported by the Associated Press. "[Lifeguards] are advising you [to] exit the water in a calm manner. The sharks are as close as the surf line." [Aahhhhh! 5 Scary Shark Myths Busted]
These are not bloodthirsty predators, but rather a group of "toddlers," said Chris Lowe, director of the Shark Lab at California State University, Long Beach. They are babies and 1- and 2-year-olds, probably 5 to 7 feet (1.5 to 2 meters) long, that are likely moving into the shallow waters because the area is safe and there's plenty of their favorite food, stingrays, Lowe said.
"During the day, they hang out very close to the surface in relatively shallow water relatively close to the beach," Lowe said. "We think they do that because that's a safe place."
Not only is this area just outside the wave break that's ideal for catching stingrays, but it's also warmer than the water located farther offshore, he said.
"Adult white sharks, which feed on marine mammals and thus pose a higher risk to humans, are less common in Southern California, although they certainly visit occasionally," said Andrew Nosal, an assistant professor of biological sciences at Saint Katherine College in San Marcos, California, and a visiting assistant researcher at Scripps Institution of Oceanography in San Diego.
Great whites congregate
Currently, great white shark toddlers have aggregated off the cities of Dana Point, Long Beach and Ventura in California, Lowe said.
Though seeing the toddler sharks in these areas is not surprising — the sites are what Lowe calls "hotspot beaches" —more groups of the animals do seem to be popping up earlier in the season, he said.
"What's different is that we're seeing multiple pockets of these sharks at known hotspot beaches. And it's odd to see them this early. Normally, it's in July or August," Lowe said. "To see that many groups simultaneously this early in the season is a little different."
That increased number may just mean there are more sharks, Lowe said. The great white shark population has been increasing in the Pacific Ocean over the past decade or so, he said. This increase has been mainly driven by protection from fishing pressure (juveniles end up as bycatch in fishing nets) beginning in 1999 in California, and the recovery of marine mammals whose numbers have been climbing since they gained U.S. protection in 1973, Lowe said.
"We think it's the recovery of marine mammals — that has been really resounding — that has enabled the white shark population to recover so remarkably," Lowe said, adding that the adult sharks' favorite foods are seals and sea lions.
As for why the babies are coming to shore earlier, Lowe said he suspects global climate change (and the associated warming of the oceans) could be one of the culprits, but there's no way to be certain.
"This could very well be attributed to global climate change, but we can't say that definitively, because we can't say what we should expect to see under non-climate-change scenarios," he said.
A healthy coastal ocean
Should SoCal residents be afraid to frolic in the surf?
Absolutely not, Lowe said, though he is not advocating that swimmers disregard lifeguard warnings. "For the last 10 years, these babies have been out there, and, in some cases, they've been at some of our most popular beaches in Southern California, [where people have been] swimming unknowingly among these baby white sharks, and nothing has happened," Lowe said. [How to Avoid a Shark Attack]
The babies receive no training from their mommies and don't even understand they could have enemies, Lowe said. As such, if swimmers go about their business, the sharks shouldn't bother the humans, he added.
"Everyone needs to make their own informed decision on whether it is safe to enter the water. I recommend heeding lifeguards' advice, even it seems to be an overreaction," Nosal said, adding that he recommends avoiding remote spots that would require long response times in the event of an emergency, and swimming with a buddy.
These baby sharks may be keeping beachgoers safer than usual, Lowe said. That's because the sharks eat stingrays, which are known to cause painful injuries to people playing in the surf in the area.
"This is a sign of a healthy ocean, a [healthy] coastal ocean," Lowe said of the aggregating great whites.
Nosal said he agrees. "It is important to remember there is no such thing as 'shark-infested waters.' Whether we like it or not, this is the sharks' home, and you cannot infest your own home. We share that space with the sharks and always have to remember that," Nosal told Live Science.
"We should also not see the sharks' presence as a threat or inconvenience," he added. "We should be excited they are here, because it means our local marine environment is healthy. When ecosystems decline, the top predators are usually the first to go."
Original article on Live Science.
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Jeanna served as editor-in-chief of Live Science. Previously, she was an assistant editor at Scholastic's Science World magazine. Jeanna has an English degree from Salisbury University, a master's degree in biogeochemistry and environmental sciences from the University of Maryland, and a graduate science journalism degree from New York University. She has worked as a biologist in Florida, where she monitored wetlands and did field surveys for endangered species. She also received an ocean sciences journalism fellowship from Woods Hole Oceanographic Institution.