Sea lions in Southern California waters had rarely posed a problem for beachgoers, surfers and swimmers. Now, scientists say a naturally occurring bloom of toxic algae, a neurotoxin, is infecting local populations of sea lions and other marine mammals,

A 15-year-old girl was attacked by a sea lion in Long Beach. Fox - LA Fox - LA. More Videos

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.

The Marine Mammal Care Center has been working to save sick sea lions in Southern California, including one on the shore of a beach. Despite the swift response time from authorities, the survival rate for the California sea lion is roughly 50%,

A 15-year-old girl was swimming in the water off Long Beach, California during tryouts for a junior lifeguard program when she was attacked by a sea lion, officials said.