A young man's ankle was injured Wednesday night at Moonlight Beach in what might have been a brush with a young great white, according to an adjunct professor at the University of San Diego.
A stretch of Moonlight Beach was closed Wednesday after a boogie boarder told lifeguards he was bitten by an aggressive shark. The beach, which was reopened on Monday after a months-long coronavirus-related closure, was immediately closed a mile in each direction. While en route to the hospital, though, in discussions with the man, it seemed more likely that he collided with or kicked the shark.
“He did say it was acting semi aggressively," Encinitas Fire Department Deputy Chief Robert Ford said Wednesday.
Lifeguards treated the incident as an aggressive shark sighting and posted advisory signs along the beach for 24 hours.
USD professor Andrew Nosal has been in San Diego since 2007, when he came here to attend graduate school at UC San Diego and study the leopard sharks that school off the coast of La Jolla. He said shark attacks are very rare in Southern California -- especially in San Diego.
"Off the coast of California, there's really only one species that can do a lot of damage and that would be the great white shark," Nosal said.
The marine biologist did not have any firsthand knowlege of the incident in Encinitas, "but from everthing I've heard, this sounds like a bump, not a bite."
Nosal added that there are other species that, in theory, could hurt a person, but they live far offshore and don't come into contat with people that often. This is in contrast to, say, Florida, where there are many species living near the coastline.
"There's no way to know for sure what species was involved [in the Moonlight Beach incident], but it sounds like this may have been a juvenile white shark," Nosal said. "This is the time of year that white sharks are born -- so the spring -- and they're typically born 4 feet in length, and these white sharks will hang out in the summer months, even into the fall, and once the water temperatures begin to drop, they will migrate south to Mexico to stay in warm waters."
Then, Nosal said, those juveniles will come back.
"Those sharks will return the following spring to Southern California," Nosal said, "and so we don't just have newborn white sharks off Southern California, we also have -- call them toddler and preteens -- as well."
The juvenile great whites can reach 10 feet in length, Nosal said. Then, when the juveniles reach sexual maturity, they swim north to central and northern California, and transition from eating mostly fish to consuming mostly marine mammals. That, Nosal said, is partly why juvenile sharks are not as dangerous to people as the adults.
"That said, an 8-foot juvenile shark can still do a lot of damage if it bites a person," Nosal said, adding, "we still don't know why sharks eat people, but one hypothesis is that it's a case of mistaken identity. A person floating in the water may look a seal or sea lion."
Nosal addressed the possibility that sharks may have been attracted to local waters because of a dead whale that was found off Bird Rock the same evening, which lifeguards towed out to sea later that night.
"In the last couple years, there have been dead whales that have attracted white sharks that were feeding on them -- even some adults," Nosal said, but he had not heard of any incidents where a sharks were feeding on a dead whale that had washed up on the beach.
These sharks, they're gonna go where there's food," Nosal said. "The smell of that whale can travel by the currents for many miles…. Maybe it attracted sharks, maybe not. It's impossible to know. Unless you're in the water monitoring for shark presence, there's no way to know if the whale had any effect."
Nosal also said he thought it was unlikely that the shark in Thursday's incident was attracted to the disturbance caused by so many people being in the water after it had been relatively calm for so long due to the beach closures.
"I mean, there are always sharks in the water, especially this time of year, whether we know it or not," Nosal said. "And the fact that even in a normal year, when everyone is in the water, we have few incidents -- that's a testament to the fact that the sharks are not interested in us."