When sea otters lose their favorite foods, they can use tools to go after new ones

A sea otter in Monterey Bay with a rock anvil on its belly and a scallop in its forepaws. (Jessica Fujii)

In parts of the ocean where sea otters face stark competition for their favorite kinds of food, some otters are getting by with the help of tools — like rocks and even glass bottles — that let them bash open tougher prey that they wouldn't otherwise be able to eat.

That's according to a new study of sea otters in Monterey Bay, California, which took a look at the tool use of individual otters to see how it affected their health and nutrition.