In the shallow waters off Elk, in Mendocino County, a crew from the California Department of Fish and Wildlife dived recently to survey the area’s urchin and abalone populations. Instead of slipping beneath a canopy of leafy bull kelp, which normally darkens the ocean floor like a forest, they found a barren landscape like something out of “The Lorax.”
A single large abalone scaled a bare kelp stalk, hunting a scrap to eat, while urchins clustered atop stark gray stone that is normally striped in colorful seaweed.
“When the urchins are starving and are desperate, they will the leave the reef as bare rock,” said Cynthia Catton, an environmental scientist with Fish and Wildlife. Warm seawater has prevented the growth of kelp, the invertebrates’ main food source, so the urchins aren’t developing normally; the spiky shells of many are nearly empty. As a result, North Coast sea urchin divers have brought in only one-tenth of their normal haul this year…