Sea otters are helping to keep marine forests off California's coast healthy and in balance by keeping the seaweed-loving urchins in check, a recent study published in the Proceedings of the National Academy of Sciences shows.

Urchins bred rapidly after a disease wiped out their main predator, the sunflower sea star, and are overgrazing on nutrient-rich kelp forests that grow along California's cold shallow coastal waters and provide shelter and food for marine life. Those kelp forests are already threatened by rising temperatures and ocean acidification.

It is understood that the otters feasting on the sea urchins will help the kelp forests to grow and play a natural role against climate change

Jessica Fujii, assistant manager for the sea otter research programme at the Monterey Bay Aquarium and co-author of the study, said: "Having a healthy ecosystem is really important for our future as we deal with the current effects of climate change ...and sea otters have a really important role to play in that. 

"They may not be able to combat everything, but their presence is going to make a huge impact on the areas that they need to survive but also that humans like to enjoy."

Sea otters are also helping eelgrass thrive in the Elkhorn Slough estuary in California's Monterey County. Since the introduction of sea otters, the area has turned into an "ecological treasure".

More than 100 endangered sea otters swim through this tidal bay daily, sharing their home waters with harbor seals, brown pelicans, egrets and other creatures.

Sea otters feed on crabs, the main predator of eelgrass sea hare slugs, which eat algae from the eelgrass. The eelgrass also absorbs carbon dioxide and provides a buffer against climate change.

Rosa Medea is Life & Soul Magazine's Chief. She writes about lifestyle including sustainable and green living.