Benthic production by micro-, meio-, and macrobenthos in the profundal zone of an oligotrophic lake

The relative contribution of microfauna (bacteria and protozoa), and metazoa (meiofauna and macrofauna) to profundal benthic production in Lake Brunnsee was examined in a 1-y study. Abundance of micro-, meio-, and macrofauna was determined and converted to biomass. Annual production was calculated using the [H-3]-thymidine incorporation method for bacteria and allometric equations for protozoa and metazoa. Bacteria had the highest biomass and production (1.5 g C/m(2) and 27 g C m(-2) y(-1), respectively). Protozoa had the highest P/B ratio, with an average biomass of 0.1 g C/m(2) and an annual production of 22 g C m(-2) y(-1). Meiobenthos and macrobenthos had biomasses of 0.1 and 1.2 g C/m(2), respectively, and production estimates of 1.6 g m(-2) y(-1) and 3.1 to 6.7 g m(-2) y(-1), respectively, depending on the method used for calculation. Although protozoan biomass was small in Lake Brunnsee sediments, production estimates suggest that they may represent an important component of the benthic community.