Cleaner water and increased populations of prey are only part of the reason, one expert says
By Gary Walker
Shark sightings are by no means rare in Southern California waters, including Santa Monica Bay. What is unusual, experts say, is how close sharks — particularly great whites — have been getting to local coastlines in recent years.
In August 2012, a great white shark circled a fishing boat in Marina del Rey and left bite marks on its motor. A month earlier, fishermen had hauled in an 800-pound mako shark in waters just outside the marina.
Last year, multiple great white sightings were reported near Venice Beach. Groups of young sharks were also seen several times near Manhattan Beach, and that summer Los Angeles County lifeguards cleared Manhattan’s El Porto Beach of swimmers and surfers after a sheriff’s helicopter spotted a juvenile great white near the shore.
In an effort to figure out why sharks have been swimming so close to beaches and to raise public safety awareness, county lifeguards convened a “shark symposium” with marine biologists on Friday at Dockweiler State Beach in Playa del Rey — less than a mile’s swim from El Porto.
“The white shark population is increasing. It is not uncommon now to see young sharks along our coasts in the summer months,” Christopher Lowe, a scientist with the Shark Lab at Cal State Long Beach, said during the symposium.
Lowe said the majority of sightings have been of young sharks and thinks part of the reason for the increase is the improving health of Santa Monica Bay.
Sarah Sikich, a science and policy director for Santa Monica’s Heal the Bay, said significant gains in water quality have led to increased populations of many forms of sea life in the bay.
“We’ve noticed that over the last five years many species of marine life have been coming back,” she said. “We’re excited to see that the charismatic and mysterious white shark appears to be one of them.”
A rise in the population of sea lions, a staple of the great white’s diet, may be responsible.
“You can’t have a predator like a great white hanging out in places if there’s no food source,” Sikich said.
Lowe thinks the larger menu of sea life is a strong explanation but suspects that isn’t the whole story.
“There has to be something more,’ Lowe said. “Our goal is to try to figure out what makes this area so special.”
During the panel, lifeguard Capt. Kyle Daniels urged swimmers and paddle boarders to avoid and definitely not to pursue sharks.
“Outside Santa Monica Bay, I’ve seen sharks eating sea lions,” Daniels said to drive home the point.
While cases of sharks attacking humans remain small in number, why sharks attack humans remains a mystery.
Lowe does not believe, as some suggest, that sharks mistake humans for food.
“We really do not know why sharks bite people,” Lowe said. “Sharks have excellent vision, so why can’t they tell the difference between a human and say, a turtle? Also, most humans are bitten, not consumed.”
Another reason to avoid sharks: despite the greater frequency in local appearances, the California Dept. of Fish and Wildlife last year designated great whites a candidate for possible threatened or endangered species protections under the state Endangered Species Act.
Great white sharks “cannot be taken or pursued. The public should take steps to avoid white sharks while fishing or being out on the water,” said Traci Larinto, a member of the department’s shark review team.
When it comes to shark encounters, “the best defense is knowledge,” Lowe said.
The catch: “There is still so much that we don’t know about shark behavior,” he said.