Toxic algae off the coast of Southern California is killing or sickening hundreds of sea lions, dolphins and seabirds, while forcing rescuers to make tough choices about "which animals to save."

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 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 California teen is recovering after she was attacked by a sea lion. The 15-year-old was training to become a junior lifeguard in Long Beach at the time. Phoebe Beltran said she received multiple injuries from the sea lion,

Two Airbnb guests were surprised to find a sick sea lion on their balcony. The animal was another victim of the toxic algal bloom that has left marine life sick all along the California Coast

Phoebe Beltran was in the homestretch of her 1,000-yard swim when she suddenly felt an intense pain as the sea lion bit her right arm.