Monday April 21, 2025
Stanford University —
Dense forests of giant kelp absorb carbon dioxide from surface waters and produce oxygen. These underwater forests also provide food and shelter to a rich array of marine species, from anemones and abalone to sea otters and giant sea bass. But huge swaths of kelp forest along the California coast have died off in recent years amid severe marine heatwaves and booming populations of sea urchins, which eat kelp.
A pair of studies from Stanford University scientists suggests restricting fishing within kelp habitats helps the forests recover and makes their ecosystems more resilient to marine heatwaves, which are predicted to become more severe and frequent with climate change.
One of the studies, published in Global Change Biology, found that kelp forest cover consistently declined off the coast of southern and central California during a severe marine heatwave between 2014 and 2016. During the five years after the heatwave, kelp forest recovery was more likely in designated “marine protected areas,” where the state has prohibited fishing since at least 2012. In areas where even minimal fishing was allowed, however, the researchers found kelp recovered scarcely more than in totally unprotected areas.