Ecological Significance of the Sea Ice Biota

Abstract

The Antarctic sea ice cover and biota associated with it play a key role in the marine ecosystems of the Southern Ocean. Due to the high biomass of autotrophic algae living at the ice/water interface and within the brine channel system of the sea ice, a large proportion of the total primary production in these regions can be attributed to these autotrophs. During winter the algae survive the harsh conditions of low temperatures, high salinities and low irradiance levels. It is during this time that they become an important food source for a number of pelagic animals particularly the southern krill Euphausia superba. During ice melt, algae are released to the water column where they may contribute to the initiation of the phytoplankton spring bloom, while sedimentation of sea ice organisms provides the benthos with food.