In what he called a terrifying brush with death, a 69-year-old man is recovering after being bit dozens of times by a pair of otters during an unexpected attack while swimming in Northern California.

Matt Leffers of San Francisco told USA TODAY the attack took place Sept. 2 while he was at his family's cabin in Serene Lakes in the Sierra Nevada Mountains, about 15 miles northwest of Lake Tahoe.

Leffers, an experienced swimmer, said he was training for a triathlon on a cold day in water he has been swimming in for 30 years.

"I was almost back to shore when all the sudden I felt something grab my leg really hard," Leffers shared.

At first he thought it his wife.

"But when I turned around no one was there," he recalled before realizing he had been bit. "And then I was bit again."

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A fight for survival

Instinctively, Leffers tried to swim away, but two otters kept "popping up out of the water in front of him", cutting him him off as he tried to get to shore.

“Within seconds, I was bit again," he said. "I tried being aggressive and they just kept biting me. I tried to float away to make myself uninteresting. But they bit me again."

So he screamed.

"I thought I was going to die," Leffers said. "But my wife came flying out on a paddleboard in between me and one of the otters. I jumped on top of her on the paddleboard and she paddled us in."

40-50 puncture wounds

Leffers' wife took him to a hospital where he learned he suffered 40-50 puncture wounds to his body.

The otters also ripped open his left arm which required 8 stitches.

"The doctor who treated me said the attack came about two months after he treated a woman who was also attacked in the same lake by otters," Leffers shared.

He was given a rabies shots and antibiotics and sent home after a stint in the hospital.

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Wildlife experts: Otter attacks on humans are rare

Peter Tira, a spokesperson for the California Department of Fish and Wildlife confirmed on Monday the agency is investigating the attack.

So far this year, there have been three confirmed river otter attacks on humans in Northern California − two at Serene Lakes and one on the Feather River in the Sacramento Valley, the state agency reported.

"While they are very rare, attacks do happen," Tira said. "They are a medium-size carnivores and we do see do instances where they attack people when they feel threatened. They are wild animals, unpredictable and territorial."

Although they appear adorable to some, Tira said a river otters physical appearance can be deceiving.

"They look very cute but they are related to wolverines and badgers and have very sharp claws and sharp teeth," Tira said. "We advise people if they see river otters not to go swimming or leave their dogs off leash. Enjoy them from afar."

'Take this seriously'

Leffers said he knows otter attacks are rare, but he hopes the state agency takes further action regarding the two "aggressive" otters that attacked him.

"I want them to take this seriously," he said.

He's not alone.

According to an undated letter obtained by USA TODAY, residents who live in the Serene Lakes community have asked the state agency for assistance on preventing another attack − specifically by two otters who recently "took up residence" in the area.

''Members of the community have contacted your office to inform the department that the two otters have allegedly attacked at least two individuals," Serene Lakes Water District General Manager Shauna Lorance wrote in the letter addressed to Chuck Bonham, the director of the California Department of Fish and Wildlife.

"The board (of directors) would like the community's request to be resolved in expeditious manner. We... are looking forward to resolution."

According to a response letter, dated Sept. 21, Raquel Elander, an environmental scientist with the state agency stated a wildlife conflict biologist conducted a site visit and agreed "the abundance of fish in the lake is likely a caused for otter presence and behavior."

The agency, according to the letter, recommended the water district "reduce the frequency of fish stocking" and limit stocking to the "non-swimming section" of the lake.

"If the pair involved in the most recent incident is a mother and pup, there is a chance the pup will disperse from the area in the coming months," Elander wrote asking for patience as the agency continues to investigate. "We will formulate a strategy once we can learn more about these otters."

'I'd hate for this to happen to a child'

Leffers said although the attack was "the most terrifying thing" he's ever experienced, he is not sorry it happened because he now has a platform to address the issue.

"Thankfully I'm a very strong swimmer. I'd hate for this to happen to a child," Leffers shared. "My calling now is to make sure some kid doesn't get killed this spring or summer when the lakes are busy."

Natalie Neysa Alund is a senior reporter for USA TODAY. Reach her at [email protected] and follow her on X @nataliealund.