A marine rescuer tells us the animals are being poisoned by a harmful algal bloom offshore from Southern California. Scientists say more frequent blooms are fueled by changing ocean conditions and nutrient pollution made worse by an increasingly warmer atmosphere.

Sea lions and other ocean mammals in Southern California are falling victim to a poisoning event that a local expert calls the worst in recent memory. It is stranding the mammals along the coast as warnings are issued to beachgoers of the threat posed by animals that are transformed by their illness.

Dolphins, sea lions and seabirds are being found sick along beaches throughout Southern California, poisoned by an unseasonably early bloom of toxic algae.