California’s Underwater Forests Are Being Eaten by the ‘Cockroaches of the Ocean’

Early on a gray summer Saturday, an unusual assemblage — commercial fishermen, recreational boaters, neoprene-clad divers — gathered for a mission at Albion Cove, a three-hour drive north of San Francisco.

“Our target today is the purple urchin,” said Josh Russo, a recreational fishing advocate who organized the event. “The evil purple urchin.”

Five years ago, assigning wickedness to the purple urchin, a shellfish the size of a plum with quarter-inch spikes, would have been absurd.

That was before the urchins mowed down Northern California’s kelp forests.

The underwater forests — huge, sprawling tangles of brown seaweed — are in many ways just as important to the oceans as trees are to the land. Like trees, they absorb carbon emissions and they provide critical habitat and food for a wide range of species. But when climate change helped trigger a 60-fold explosion of purple urchins off Northern California’s coast, the urchins went on a feeding frenzy and the kelp was devoured.

“It would be like one of those beautiful deciduous forests turned into a desert,” said Gretchen Hofmann, a professor of marine ecology at the University of California, Santa Barbara. “But in the matter of five years.”

Read the entire article at NYtimes.com