Abstract
In order to relate the benthic lipid composition to possible sources in the water column, the sestonic communities of a monomictic lake were profiled using their saponifiable polar lipid fatty acids, which were identified by capillary gas chromatography-mass spectrometry (GC-MS). The epilimnion, dominated by the dinoflagellate alga Ceratium hirundella was characterized by C sub(20:5) and C sub(22:6) polyunsaturated fatty acids. The concentrations of several unusual fatty acids found in Desulfovibrio spp., Desulfobacter spp. and Desulfotomaculum spp. were inversely related to sulfate concentration in the metalimnion.