SAN FRANCISCO (KTVU) - A recent rash of sea lion attacks along the San Francisco Bay have prompted concerns for swimmers who frequent the chilly waters.
Irene Chan, 65, was doing her usual swim with a friend in Aquatic Park around 6:45 a.m. Thursday when she says "out of nowhere" a sea lion bit her leg.
"This is actually unusual behavior," said staff veterinarian, Dr. Cara Field, of the Marine Mammal Center, regarding the inexplicable attacks. "It is easy to forget that they are wild and, sometimes as wild animals, they may be unpredictable."
A retired paramedic swimming in the cove at the time helped Chan until emergency crews arrived. The woman was taken to a trauma center, according to San Francisco fire. Her injury is non-life threatening.
The previous attacks occurred Dec.14 and 15.
In one of the incidents a man was taken to a trauma center with non-life threatening injuries. Marine mammal specialists aren't sure if the same sea lion was responsible for both attacks.
Swimmers in the area identified the man as Rick Mulvaney. He was bit in the groin. Additional details on that attack have not yet been released.
In the first attack, 56-year-old Christian Einfeldt was swimming beyond the cove at Aquatic Park and was bitten around 1:45 p.m. Thursday, Dec. 14.
Einfeldt, an attorney and experienced swimmer who has been coming to the area for more than two years, tells KTVU he feared for his life when he was bit by the sea lion. The attack happened about a quarter mile from the shore.
"He was a bull- you can tell by the head they have a bump on the head called a sagittal crest," said Einfeldt. "So I knew it was a male and with his mouth he was displaying his teeth at me."
A sailboat happened to be nearby and saw the swimmer in distress, so he pulled Einfeldt onto his boat and immediately called police.
Police told the captain of that boat to bring him to the Hyde Street pier.
John Baxter with the San Francisco Fire Department tells KTVU several tourniquets were applied to the swimmer in an attempt to stop the bleeding. The tourniquet was applied by SFPD at Pier 45.
The swift actions by emergency crews contributed to the swimmer's life being saved, according to San Francisco Fire. Einfeldt was then transported to Zuckerberg San Francisco General Hospital and had a nickel sized hole of exposed muscle on his arm.
Scientists have predicted that the unexplained behavior could be due to a biotoxin that affects the mammals' brains, throwing them off kilter. The sea lions could also be hurt. Our KTVU found an injured sea lion at Pier 39, whose neck was sliced open by what appeared to be a fishing line.
"If they're feeling pain or something like that and somebody is near them then they may just react defensively," said Dr. Field.
Despite the attacks swimmers from Aquatic Park's Dolphin Club and South End Rowing Club say they'll still work out in the water, but they're more "on-guard" for any potential sea lion encounters.
"They say you're supposed to like swim back gently, no thrashing movements," said George Thomas Howell of the South End rowing Club.
Some experts have attributed the sea lions' odd behavior to a recent dip in the herring population, causing the animals to get more territorial over their feeding zones.
Einfeldt says that makes sense. At least three victims were attacked near the so- called "sea lion highway."
"It was actually kind of stupid to be swimming on the sea lion highway. In a sense it was my fault, but I'm going to swim close to shore now," he said.
Einfeldt is headed back into the water next week after he receives an ok from his doctor.
Chan, meanwhile, is out of the hospital and recovering at home on antibiotics.
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.
Leigh Martinez and Tara Moriarty contributed to this report.