Variation in physical, chemical and biological components in the subantarctic lakes of South Georgia

Physical, chemical and biological variables were quantified in 19 subantarctic lakes (South Georgia) as a prelude to comparing these pristine systems with temperate lakes and to improve the knowledge of spatial and temporal variation in water chemistry and abundances of organisms Lakes close to the sea had higher phosphorus concentrations, contained higher abundances of most organisms, and had higher number of invertebrate species than lakes situated further from the sea. Differences were attributed to higher nutrient input from marine organisms, such as penguins seals and petrels and probably also to a somewhat longer ice-free period Since the lakes of South Georgia lack fish, the pelagic invertebrate fauna is dominated by herbivorous macrozooplankton Rotifers are rare in the open water and are restricted to the vegetation (mainly mosses) in shallow areas and to the sediment surface Generally, the algal abundance at the sediment surface is high in subantarctic lakes, indicating that the main part of the primary production is provided by benthic algae, which is in contrast to what is normally the case in temperate waters

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