It is late autumn in the Pacific Ocean. In waters off the unpopulated Moyururi Island of eastern Hokkaido’s Nemuro City, some ten or more sea otters gather together and float luxuriously on the water surface.
The group even has a mother holding her baby. She wraps their bodies in long seaweed to rest without getting swept away by the current. When a boat with its motor turned off slowly approaches on the flow of the current, the sea otter group divides into sea otters that eye the situation calmly and sea otters that keep a constant distance from the boat.
The sea otter is a member of the weasel (Mustelidae) family that left its land cousins for the ocean. They dive lithely under the water to catch their prey. The sea otter swimming speed is as low as 9 km/h, making them slow in comparison to other marine mammals like the earless seal. When waters become turbulent, they are sometimes tossed about on waves and can even smash up against seashores and suffer injuries or die.
From autumn through winter low-pressure systems pass along the eastern Hokkaido coast multiple times. Sea otters will face a season of turbulence that is even harsher to them than the cold.