9310687 Roman A major goal of the U.S. JGOFS Arabian Sea Process Study is to examine the role of this region in global biogeochemical fluxes, particularly in sequestering carbon below the pycnocline. Mesozooplankton are important in this process because they consume suspended material and facilitate its removal from surface waters by the production of rapidly sinking (> 200 m d-1) fecal pellets. Because of this enhancement of the vertical flux of biogenic material, mesozooplankton research is a "core" area of JGOFS. Dr. Roman will conduct measurements of mesozooplankton biomass, grazing and fecal pellet production in the Arabian Sea Program. The research goal is to determine the role of mesozooplankton in biogenic flux in the Arabian Sea. The research objectives are to: (1) estimate the biomass (C, N) of different size classes of mesozooplankton (64-2000 um) in the Arabian Sea and to determine how this biomass is vertically and horizontally distributed; (2) estimate the consumption of photosynthetically fixed carbon by different size classes of mesozooplankton; (3) estimate the consumption of heterotrophic carbon (ciliates and flagellates) by different size classes of mesozooplankton; (4) estimate the potential rates of carbon and nitrogen export in the form of fecal pellets by different size classes of mesozooplankton; (5) determine the effect of suboxic waters on mesozooplankton biomass and grazing.