World

Otters, kelp beds and CO2

Otters: Cute, and useful
Stuart Westmorland/Getty Images

Sea otters, arguably the world’s cutest endangered species, have also turned out to be one of Mother Nature’s best animal carbon sinks. It’s believed they can pull up to 0.18 kg of C02 out of the air for every square metre of water they occupy, by keeping kelp beds healthy.

They’re only at about a third of what their population once was, but if their numbers were back to the estimated 300,000 before they were hunted to near extinction in the 18th and 19th centuries, they would be responsible for the sequestration of about 10 billion kg of carbon dioxide a year.

The information comes from new research conducted by a team of scientists at the University of California. Sea otters help kelp beds by eating sea urchins, which are decimating the carbon-sucking kelp because they’ve exploded in population in areas that used to be otter stomping grounds. As a result, a huge amount of carbon dioxide is staying in the air. But can otters make a comeback? At one point there were only about 1,000 to 2,000 otters left, meaning their gene pool is now very small, and that, unfortunately, makes conservation efforts difficult.