Satellite imagery shows that the area covered by kelp forests off the coast of Northern California has dropped by more than 95 percent, with just a few small, isolated patches of bull kelp remaining. Species-rich kelp forests have been replaced by “urchin barrens,” where purple sea urchins cover a seafloor devoid of kelp and other algae.
A new study led by researchers at UC Santa Cruz documents this dramatic shift in the coastal ecosystem and analyses the events that caused it. This was not a gradual decline, but an abrupt collapse of the kelp forest ecosystem in the aftermath of unusual ocean warming along the West Coast starting in 2014, part of a series of events that combined to decimate the kelp forests. MORE
Header image: Satellite images show the dramatic reduction from 2008 to 2019 in the area covered by kelp forests (gold) off the coast of Mendocino and Sonoma Counties in Northern California. Credit: Meredith McPherson.