Comparisons Between Lakes and Seas During the Arctic Winter^*

* A version of this paper was presented at the Circumpolar Ecosystems in Winter Symposium, 16.21 February 1990, Churchill, Manitoba, Canada.

Abstract

Lakes and seas are oases of life in winter, when the land is frozen. Differences between lakes and seas result because the sea has a much higher salinity and much larger size. Thus the frozen sea has a lower temperature, a macroscopic porous ice structure at the water interface, higher current velocities, and discontinuous ice cover compared with frozen lakes. Both systems exhibit complex differential movements of water masses with differing solute content resulting from freezeout distillation. The biological differences resulting from the physical differences include the absence of ice communities, shorter food chains, lower diversity, lower benthic and higher fish biomass, and lack of mammals and birds in lakes compared with seas in winter.