This research project will study trophic relations in benthic microbial food webs. The objectives are: (1) to estimate the rates of bactivory and herbivory of benthic nanoflagellates, ciliates, nematodes, copepods, and other organisms in tidal-flat communities; (2) to compare the trophic structures of several distinct types of intertidal microbial communities inhabiting exposed sandy, protected sandy and muddy beaches; and (3) to examine changes in the trophic structure of the benthic microbial community in course of seasonal succession. These objectives will be conducted through field grazing experiments using fluorescent-labeled bacteria and diatoms as food tracers. This approach has been used previously to study planktonic protozoan grazing and it will be adapted here for studying benthic metazoans. A part of this novel experimental design has been already tested in the field. The advantage of this experimental design is that it allows simultaneous measurements of microbenthic bactivory and meiobenthic herbivory. These data are needed to analyze the energy flow through benthic communities, to evaluate the role of grazing in controlling bacterial and algal production and to examine food competition among protozoans and meiofauna. This research will describe a unique data set that is currently unavailable for any benthic community.
