The Case of Catastrophic Kelp Loss
For more than five years, divers and scientists along the U.S. West Coast have watched a disaster play out before their eyes. Sunflower sea stars fell victim to a wasting disease, which wiped out roughly 90 percent of the global population in 2013. Seven years later, scientists see no signs of recovery. Without the sea stars, the population of purple urchins that sea stars eat has exploded and mowed down entire forests of bull kelp. The West Coast experienced intense ocean warming from 2014 to 2017, and by 2015 divers began seeing urchin barrens — vast swaths covered in piles of spiny creatures and little else.