Marine experts say these attacks are not common, but are happening more often. That’s due to a toxic algae bloom that are poisoning marine mammals, making them become aggressive and violent as they travel to shallow water and get closer to humans.

The toxicity of this particular bloom seems to be a lot higher, ” said a marine biologist. “Animals are in worse shape than they have been in the past.”

A teenage girl and junior lifeguard candidate was attacked and bitten in the arm by an aggressive sea lion during a tryout in Long Beach on Sunday, March 30. The attack occurred around noon in the ...

"My initial reaction was, 'I'm getting eaten in the middle of the water, it's a shark, I'm going to die,'" Phoebe Beltran told ABC News. Phoebe Beltran immediately screamed for help, which is when the animal -- she later found out was a sea lion -- let go of her arm.

Experts say frightening encounters with sea lions are becoming more common and the likely reason for recent attacks is a toxic algae bloom poisoning the marine mammals, leading to rare acts of aggression as they move to shallow waters and in closer proximity to beachgoers.

Sea lions in California waters have been reportedly more aggressive as of late. Recently, a teenager was attacked by one while taking a test to become a lifeguard. KTLA-TV reports how 15-year-old Phoebe Beltran of Long Beach had been swimming near a lifeguard tower when one of the sea creatures suddenly bit her.

A 15-year-old Long Beach girl is still recovering from a sea lion attack that happened while she was swimming over the weekend.