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
Ice amphipods and polar cod are preyed upon by seabirds and In the Antarctic, krill represent the primary food source for
marine mammals
41,42
. The younger polar cod, which can be squid, penguins, some seals and baleen whales, while copepods
found in drifting pack ice, are a particularly important and avail- dwelling in the sea ice are an important food source for adult
able food source for seabirds and marine mammals feeding in krill. When krill populations are low, in years following reduced
the marginal ice zones
43
. ice extent, salps (gelatinous, barrel-shaped organisms that look
rather like jellyfish) are able to exploit the spring bloom of phy-
The annual biomass of ice fauna transported with the transpo- toplankton (free-floating algae) and undergo explosive popula-
lar ice drift to Fram Strait and the Barents Sea is in the range of tion growth in Antarctic waters
39
.
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.
80 GLOBAL OUTLOOK FOR ICE AND SNOW
80 GLOBAL OUTLOOK FOR ICE AND SNOW