SAN FRANCISCO (CBS SF) -- Attacks by sea lions or seals like the one that left a swimmer near San Francisco's Aquatic Park with serious injuries Thursday are fairly rare, an expert said.
A seal or sea lion bit the swimmer on his upper right arm shortly before 2 p.m. Thursday as he swam outside of Aquatic Park, according to police.
Officer Matthew Reiter with the San Francisco Police Department's Marine Unit said the solo male swimmer was brought to police by a sailboat that reported a swimmer in distress.
He was bleeding badly from the bite wound and police applied a tourniquet and pressure to stop the bleeding before transferring him to paramedics for transport to a hospital.
"He told us that he was swimming when a sea lion came up to him," Reiter said. "He said he splashed water at it, he yelled at it when that didn't work, the sea lion came up to bite him and he used his arm to push it away."
Reiter said such attacks were uncommon and he had not seen one before during his time with the marine unit.
Dr. Claire Simeon, a veterinarian with the Marine Mammal Center, published a study with the University of California at San Francisco in 2015 looking at sea lion and seal bites and scratches.
She said researchers talking to the members of two San Francisco swim clubs found only 11 such incidents over a period of three years and one of those had actually taken place in Washington.
The study found no clear patterns or common causes among the incidents. While it was clear that approaching the animals could cause negative reactions, many of the swimmers did not appear to have done anything to provoke the attack.
"As these animals are wild, their behavior can be erratic," Simeon said.
Experts recommend that swimmers and beach goers try to maintain a safe distance from seals and sea lions, as they have sharp teeth and a strong bite.
"I don't think that people should be afraid to go into the water," Simeon said. "We're lucky to be able to share our coastline with these amazing animals."
"We really want people to leave seals be and enjoy the bay," Simeon said.
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