'It looked possessed' - sick sea lions attacking beachgoers in California

For 20 years, Rj LaMendola found peace while paddling in the water on his surfboard.

But last month off the coast of Southern California, the ocean turned hostile after a sea lion lunged at him, bit him and dragged him off his board.

"It looked possessed," Mr LaMendola wrote in a Facebook post, saying the animal involved in the encounter just north of Los Angeles was "feral, almost demonic".

The surfer later learned the animal was suffering from domoic acid toxicosis- a neurological condition caused by a harmful algal bloom. It's one of dozens of sickened animals that have been spotted across California beaches recently - many suffering from symptoms like seizures or intense lethargy. The toxin often leads to death.

This particular algae bloom has appeared four years in a row across California, raising concerns it might be turning into an annual event. The bloom of algae started earlier than normal this year and has spread roughly 370 miles of the iconic Southern California coastline.

When Mr LaMenolda made it to shore, his wetsuit ripped open, he was bleeding and went to the hospital. "It felt like I was being hunted," he said.

South of where he was attacked, 15-year-old Phoebe Beltran was doing a swim test in Long Beach to become a lifeguard when a sea lion repeatedly bit her.

"I was just so scared, so shocked, but I still felt the immense pain on my arms, like, over and over again," the teen told local US media.