SAN FRANCISCO (CBS SF) — A female swimmer was bitten by a sea lion in the waters of San Francisco’s Aquatic Park early Thursday, the fourth such attack in those waters in less than a month.

A spokeswoman at the Dolphin Swim and Boat Club said the woman — identified as Irene Chan, a well-known swimmer with the club — was taken to San Francisco General Hospital by ambulance after the attack at just before 7 a.m.

San Francisco Fire Department said the woman suffered a non-life threatening bite to the leg. Chan was rescued by a retired paramedic who happened to have been swimming there.

Swimmer Alice Ma was swimming nearby and heard Chan call for help.

She was one of the first swimmers to reach her and also helped guide her to shore about a quarter mile away.

“I said, ‘Do you want me to pull you in?’ And she said, ‘No. No, I can swim by myself, I just can’t kick,'” said Ma. “It looked like the sea lion had bit her on both sides. What Irene told me was the sea lion clamped down onto her. It bit her and pulled.”

Bob Tandler was at the nearby South End Rowing club and saw the woman being helped from the beach. He said the attack took place near the end of the muni pier.

“She was bleeding from the lower thigh just about the knee,” he said. “There were a couple puncture wounds just above the knee cap.”

Tandler said he knew Chan and that she often swam in the bay.

“She’s a strong, experienced swimmer,” he said. “But she appeared very weak — somewhat traumatized.”

Tandler is a regular swimmer of the cove and said after the attack he did a couple laps but stayed close to the shoreline.

Another sea lion attack at SF’s aquatic park. Bryant Robledo, a carpenter working on the dock, saw the female swimmer come in assisted by fellow SERC members. @CBSSF pic.twitter.com/MZ8kKnf1lN — Joe Vazquez (@joenewsman) January 11, 2018

Bryant Robledo is a carpenter who was working on a nearby dock and saw Chan getting pulled to shore.

“She said she was swimming and didn’t see anything because it was really dark at that time in the morning. And she was just in shock,” said Robledo.

Thursday’s incident was the fourth attack on swimmers by sea lions at Aquatic Park in the past month.

In mid-December, three swimmers were attacked in separate incidents in the span of a week. Officials with the San Francisco Maritime National Historical Park temporarily prohibited swimming in the popular cove.

“She was out at what we call the Jacuzzi, which is at the end of the pier just out there where there’s a circular area there. Tides tend to swirl around a little bit, which is why we call it a Jacuzzi,” explained Tandler.

The National Park Service said Chan was attacked in the exact spot where two of the swimmers who were bitten by sea lions in December were attacked.

A decline in herring population over the last five years may be to blame.

The NPS told KPIX 5 they have noticed sea lions getting more territorial over their feeding zones.

The Jacuzzi is one of those zones.

The National Park Service has left this area open for now, but that may change later Thursday.