Beginning in 2014 the urchin density around the Monterey Peninsula and Carmel Bay went from one urchin every 25 square meters to 10 urchins in one square meter.
Purple Urchins love giant kelp and primarily rely on the detritus that fall to the ocean floor as their primary food source. In recent years, Tankers Reef’s population of purple urchins has transitioned to wiping out the 20 acres of live kelp that once thrived here. The urchins bore holes into the shale at Tankers Reef and rapidly proliferated into urchin barrens where kelp can no longer grow.