Published online by Cambridge University Press: 27 October 2009
Seasonal ice of the Southern Ocean, occupying some 15 x 106 km2, supports a distinctive biota based on algae that live on, within and immediately beneath the ice floes. How this annually-forming habitat recruits its biota, and the fate of the biota after the ice thaws in late summer, are little-known. Studies in the Weddell Sea in 1984–88 have shown that the seasonal ice is important as the wintering substrate of krill Euphausia superba which, together with other zooplankton and fish, supports a large breeding population of seals and penguins. Clearly a key habitat in the economy of the Southern Ocean, this seasonal ice is likely to be vulnerable to small climatic changes.