Before 2013, divers on North America’s west coast rarely saw purple sea urchins. The spiky animals, which are voracious kelp eaters,- were a favorite food of the coast’s iconic sunflower sea stars. The giant sea stars, recognizable for their many arms, kept the urchin population in check, with the help of sea otters, lobsters and some large fishes.
That balance allowed the local kelp forests to flourish, providing food and protection for young fish and other sea life.
