Purple Sea Urchin populations have exploded along the northern California coast, creating "urchin barrens" where all the algae has been eaten - including Giant Kelp and Bull Kelp - leading to the loss of most of the vital "kelp forest" habitat. Why is this happening?
On The Ecology Hour, hosts Tim Bray and Bob Spies talk with Dr. James Estes, emeritus professor of Ecology at the University of California - Santa Cruz, one of the foremost experts on Sea Otters. Dr. Estes explains how the disappearance of these predators a century ago contributed to the loss of kelp forests here and elsewhere.
This interview was conducted a few months ago and in the intervening time the situation has remained dire; on the Mendocino coast there are only tiny patches of visible kelp. Competition with urchins for food has placed stress on the Red Abalone population, and the recreational season has been suspended for at least two years. We are only beginning to see the effects on beach structure, ocean bluff erosion, and the nearshore ecosystem.
Dr. Estes does offer hope, by describing similar collapses that have occurred in kelp forest ecosystems elsewhere in the world and how they eventually recovered. The story continues to unfold.
The interview will broadcast on The Ecology Hour, Tuesday August 13 at 7:00 PM.