Off California, sea otters feast and play a part in climate change battle

MOSS LANDING, Calif.: Sea otters are helping to keep marine forests healthy by feasting on the seaweed-loving urchins whose numbers have exploded off California's coast, researchers have found.

Urchins have bred profusely after a disease wiped out their main predator, the sunflower sea star, and are overgrazing on nutrient-rich kelp forests that grow along California's cold shallow coastal waters and provide shelter and food for marine life. Those kelp forests are already threatened by rising temperatures and ocean acidification. Sea otters are restoring balance with their appetite, keeping the urchin population in check, a recent study published in the Proceedings of the National Academy of Sciences shows.