The biological significance of open water within the sea ice covers of the polar regions

The popular concept of the sea ice of the Polar regions as unbroken areas of snow and ice is far from reality. There are in fact always considerable areas of open water, including some of considerable size which are normally to be found in the same place from year to year. The mapping of these areas has lately been much facilitated by remote sensing from polar orbiting satellites. This unusual ecological niche has been exploited by a specialized community of plants and animals.