9310595 Bott Meiofauna (animals between 50 and 100 microns in size) feeding studies will be conducted in situ by following the accumulation in animals of flouorescently labeled bacteria and algae added to flumes inserted in the streambed. Simultaneous measures of bacterial and algal productivity using 3H thymidine and oxygen change procedures, respectively will allow assessment of the proportion of production consumed by meiofauna. Other grazing experiments will indicate whether protozoa are important intermediates in the transfer of energy from bacteria and algae to meiofauna and the extent to which meiofauna consume protozoa. Finally, we will manipulate meiofauna densities and concentrations of dissolved organic matter to see whether those predators or nutrients, or both acting interactively or addictively regulate bacterial and algal densities and productivity. %%% Meiofauna are a conspicuously understudied group of organisms in streams, and the research here investigates their impact on epibenthic bacteria and algae, as well as the relative importance of nutrients and bacterivory in controlling bacterial biomass in streams.
