In California, Bring Hammers on Your Dive

In an ironic twist in conservation efforts, California divers are encouraged to smash sea urchins with hammers. In many parts of the world scientists are concerned that sea urchin populations are declining, with resultant uncontrolled growth of algae on rocks and corals. But not in California, where scientists have declared war on sea urchins. The spiny invertebrates are gobbling up coastal kelp faster than it can reproduce.

The trouble lies in the recent demise of the sea urchins' key predator, sea stars, which eat them. According to scientists, global climate change has caused the Pacific Ocean to overheat, and it's killing the sea stars. On beaches in Mendocino and Monterey, fish and game wardens are now encouraging recreational divers to bring hammers on their dives to smash any urchins they see.