The kelp beds of the Channel Islands are under assault.
Experts say the main culprits are people and purple sea urchins.
Purple sea urchins strip the kelp from base to tip, leaving only sand. They're not the variety favored by fishermen and sushi lovers. Besides killing the kelp, the purple urchins have been crowding out the more delectable red sea urchins. It's a very bad situation,' Glantz said. Besides the purple urchin influx, pollution, boat anchoring and overfishing of natural sea urchin predators, like sheephead and lobster, have hurt the forests.