Shiretoko has a rich marine ecosystem and a highly primitive land ecosystem due to the influence of drift ice, it is an important habitat such as rare species and marine mammals around the world. It was evaluated and registered on World Natural Heritage on July 17, 2005.
Shiretoko 's sea is covered with drift ice in winter. Plankton is nourished by drift ice carried nutrients, Steller's sea eagles and seals are benefiting from it.
The salmon which stored the nutrient of the sea also goes up the river of the hometown, where it becomes a food for mountain creatures such as bear brown, the body of a salmon that ended life return to the earth and enrich the forest. Such circulation of life was valued very much as a precious ecosystem.