Environmental factors controlling biological productivity in the Sea of Okhotsk-River, Sea-Ice and Intermediate Water

Abstract

Although the Sea of Okhotsk is characterized as the lowest latitudinal area of seasonal sea-ice in the world, the influence of sea-ice to biological production have not been well understood in the Sea of Okhotsk. In fact, the sea-ice does not contribute the primary productivity very much, but it produces a dense shelf water which penetrates into offshore intermediate water carrying large amount of organic matter produced on the continental shelf under the influence of river water discharges. This organic-rich intermediate water does not only support large heterotrophic biomass there, but also may contribute the primary production in the northwestern North Pacific via vertical mixing of the terrestrial nutrients at Kuril straits.