A local swimmer believes his perilous encounter with a sea lion off La Jolla should serve as a warning to all swimmers — especially in light of recent red tides.

La Jolla Cove Swim Club member Steve Pruett said he was on one of his many swims from Scripps Pier to La Jolla Cove around 10:30 a.m. Nov. 10 when he was bitten on a thigh by a sea lion.

Pruett, 69, said he is a lifelong swimmer who covers 200-300 miles in the ocean every year and is familiar with local conditions.

But on this day, a red tide was causing low visibility. Red tides, which are large algae blooms, happen on a near-annual basis and help produce phytoplankton that serve as part of the ocean food web.

“I wanted to do a 4- or 5-mile swim, but there was such poor visibility,” Pruett said. “In some areas, the [algae bloom] was four feet below the surface. In other places, it was right at the surface, so I could only see a foot or so beneath me.”

At some point amid the low visibility, Pruett made contact with a sea lion.

“I was swimming along, it was nice and flat and then ‘wham,’ it felt like someone punched me as hard as they could. It was this huge impact,” he said. “I bolted up, hoping it wasn’t a shark. When I got to the surface, I saw a sea lion three feet in front of me with its mouth open barking. So as best I can guess … I may have just swum into a pod of sea lions and startled it.”

After kicking and flailing to scare the sea lion away, Pruett rolled onto his side to examine his leg and saw “I was bleeding pretty badly.” He made his way to shore and “I was near enough to a lifeguard, so I hobbled up and got assistance.

He was taken to an emergency room with a circular bite on his thigh — “one large [puncture]” and five smaller puncture wounds on the underside.

“Fortunately, because I was going to do a long swim, I had a sleeveless wetsuit on,” Pruett said. “I think that stopped me from getting more significantly injured. I’m also lucky that it bit my leg rather than my torso. Those would have been really bad injuries. This is no fun, but it could have been worse.”

La Jolla Cove Swim Club member Steve Pruett recently was bitten by a sea lion during an outing in La Jolla waters. (Judy Pruett)

In addition to the low visibility caused by the red tide, Pruett and other swimmers expressed concern that the sea lion might have been more agitated than usual because of possible exposure to a neurotoxin known as domoic acid.

Domoic acid is produced by the rapid growth of an algae called pseudo-nitzschia, according to the National Oceanic and Atmospheric Administration. Some large algae blooms can contain high levels of the toxin, which has been known to cause sickened sea lions to experience seizures, disorientation and hyper-reactivity, sometimes resulting in bites.

Such a bloom off Ventura and Santa Barbara counties last year resulted in more than 1,000 reports of sick and dead marine mammals thought to have been exposed to the algae, NOAA Fisheries said. San Diego and Orange counties also were affected.

Scientists recently developed a predictive model intended to determine whether algae blooms will be harmful. One of them is Bradley Moore, a professor of marine biology, marine chemistry and geochemistry at UC San Diegos Scripps Institution of Oceanography in La Jolla, who told the La Jolla Light that he doesnt think the bite Pruett suffered was due to domoic acid exposure.

“Domoic acid producing diatoms are rarely in La Jolla waters, so I would highly doubt there are local exposures,” Moore said.

However, though the effects of domoic acid have been seen north of San Diego, a similar event “absolutely” could happen in La Jolla, according to William Gerwick, a professor at Scripps Oceanography who told the Light last year that “we’re at the whim of the phenomena of the sea; we can’t mitigate it.”

“If a bloom develops, there is not a whole lot we can do to terminate it, Gerwick said. We have to learn how to live with them.”

Pruett said he based his concerns on past experiences.

About five years ago, he said, “I had a run-in with an aggressive sea lion [that] blocked my path and wouldn’t let me swim. It would swim at me with its mouth open, which was pretty alarming. That was also during a red tide.”

Monica Muñoz, a spokeswoman for the San Diego Fire-Rescue Department, which includes the lifeguard division, offered several safety recommendations for swimmers who decide to go in the water during a red tide:

• Swim near a lifeguard and stay close to shore in designated swimming areas.

• Check the water, rip current and weather conditions before swimming.

• Swim with a partner or group.

• Know your limits and make sure youre comfortable.

• Ensure you are a strong open-water swimmer. This should not be your first open-water swim.

• Use a swim buoy, marker or brightly colored flotation device.

• Use familiar swimming techniques and stay in familiar areas with an on-duty lifeguard.

• Consider wearing swim fins and use proper gear: brightly colored swimwear, caps, goggles and wetsuits with reflective tape.

• Have a plan for an emergency or separation from your partner and for a safe exit.

• Always prioritize safety and be prepared to get out of the water if conditions worsen or you feel unsafe.

“If someone is not a regular ocean swimmer, when it is a red tide, I would stay close to a lifeguard station,” Pruett said. “If you swim out of The Cove, I wouldn’t go more than a quarter-mile. If you are swimming at La Jolla Shores, stay by the station.

“The less experienced you are, the more conservative I would be. I was maybe a little cavalier because I swim so much in the ocean and have swum in red tide before, but this time I paid the price. So going forward, I am going to be more careful.”