The Ecoregions of the Oceans

Abstract

At times, or during the winter, ice of the Arctic or Antarctic Oceans covers the regions of the polar domain. They are characterized, in general, by ocean water that is greenish, low in temperature, low in salt content, and rich in small, sometime microscopic plant and animal organisms, know as plankton. The duration of ice provides a basis for division into (a) an inner polar zone (division) covered by ice for the entire year, and (b) an outer polar zone (division) where, with a 50% probability, ice is encountered during winter and spring.