An Abundant Diversity of Marine Mammals, the Sign of a Productive Sea.
In the productive waters surrounding the Shiretoko peninsula, eight species of whale have been observed. The presence of these marine mammals, the top level of the ecosystem, is a clear sign of the abundant living resources in these seas.

Moving south with the sea ice, a large number of Harbour and Ribbon seals make their way towards Shiretoko each winter. Other species including Ringed seals (Phoca hispida ) and Bearded seals (Erignathus barbatus ) also migrate with the ice, making the waters around Shiretoko one of the southern-most gathering areas for seals in the Pacific region. In late March and early, April, seals give birth and raise pups on the sea ice, a natural sort of rocking cradle.