Partial photo: Anchor Lee
Sea otters keep themselves warm by eating a quarter of their body weight in food a day, and when that includes eating sea urchins, it helps support kelp forests ecosystems in the North Pacific. Without this the urchins basically clear cut the kelp, chewing through the holdfasts at their base and sending the rest of the giant algae to wash away. Otters can also benefit seagrass in zones, where they mostly feed on crabs. When they bring down the numbers of crabs, grazing organisms that the crabs eat rebound. These slugs and snails often don’t eat the seagrass; instead they scrape away the algae that grows on the grass, which allows the seagrass to absorb more sunlight and grow more efficiently. Like kelp, seagrass absorbs carbon as it grows, and stores much of it in its roots. When older roots die, the carbon becomes locked in the sediments, where it can take hundreds of years or more to convert back to its gaseous form.
www.bbc.com/future/article/20210914-how-sea-otters-help-fight-climate-change