intra-species variation is observed with regards to the northern pacific and the southern pacific. in point lobos, the use of tools to open mussels is very common. this behavior is distinctly less common in northern areas like the commander islands and kuril islands. there, adult otters only use tools if they are unable to open food items after trying first with their teeth. alaskan otters do not use tools as often as californian otters. californian otters show multiple techniques with differences that are tailored specifically to eating bivalves and crabs.