Dense forests of giant kelp absorb CO2 from surface waters, produce oxygen, and provide food and shelter to many marine species, from anemones and abalone to sea otters and giant sea bass. 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. Restricting fishing within kelp habitats helps the forests recover and makes their ecosystems more resilient to marine heatwaves, predicted to become severe and frequent.
https://news.stanford.edu/stories/2025/04/research-fishing-bans-kelp-forests-marine-heatwaves