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 Species-rich kelp forests have been replaced by "urchin barrens," where purple sea urchins cover a seafloor devoid of kelp and other algae.
source https://phys.org/news/2021-03-collapse-northern-california-kelp-forests.html
