Global Outlook for Ice & Snow

Adelie penguins on sea ice. Photo: Armin Rose/iStockphoto.com

Sea ice and food webs: complex linkages among ice, oceans and many forms of life

In the Antarctic, krill represent the primary food source for squid, penguins, some seals and baleen whales, while copepods dwelling in the sea ice are an important food source for adult krill. When krill populations are low, in years following reduced ice extent, salps (gelatinous, barrel-shaped organisms that look rather like jellyfish) are able to exploit the spring bloom of phy- toplankton (free-floating algae) and undergo explosive popula- tion growth in Antarctic waters 39 .

Ice amphipods and polar cod are preyed upon by seabirds and marine mammals 41,42 . The younger polar cod, which can be found in drifting pack ice, are a particularly important and avail- able food source for seabirds and marine mammals feeding in the marginal ice zones 43 . The annual biomass of ice fauna transported with the transpo- lar ice drift to Fram Strait and the Barents Sea is in the range of a million metric tons 37,44 .This biomass is released to the open ocean and ocean bottom systems as the ice melts 45 and is an important source of nutrients.

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GLOBAL OUTLOOK FOR ICE AND SNOW GLOBAL OUTLOOK FOR ICE AND SNOW