Pod of around 1,000 dolphins spotted off coast of Rausu 20220107

On December 12, a large pod of dolphins appeared off the coast of the town of Rausu in the Nemuro region of eastern Hokkaido. According to fishermen and other witnesses, a pod of what appeared to be over 1,000 Pacific white-sided dolphins, stretching over 700 to 1,000 meters, swam along the coast toward Kunashiri Island in the Northern Territories. It is rare to see so many Pacific white-sided dolphins at once off the coast of the town.

　Mr. Sakurai, a fisherman, spotted the pod of dolphins splashing in the calm waters approximately 1.8 kilometers off the coast of Minehama-cho in the southern part of the town at approximately 10 a.m. “I thought it was a school of tuna because they were jumping around and there were birds flying overhead."

　At around 1 p.m., the pod of dolphins was also seen approximately 15 kilometers north of the Rausu fishing port, and Mr. Yoshida, a civil servant in the town, took photos and a video from the port. “I zoomed in and saw it was a pod of Pacific white-sided dolphins; I've never seen anything like it,” he said in amazement.

　According to Sakurai Yasunori, professor emeritus at Hokkaido University and expert on marine mammals and fish, the sea temperature in the Nemuro Straits on that day was 6 degrees Celsius at the sea surface, and 7 degrees Celsius at a depth of 50 meters. “This is the lower limit of the water temperature in which sardines and anchovies – which the dolphins feed on – can live. It is possible that the dolphins were chasing a school of sardines,” he said.