Roman¹, Michael, Larry Small² and Xinsheng Zhang¹

¹Horn Point Laboratory, University of Maryland Center for Environmental Science, P.O. Box 775, Cambridge, MD 21613, U.S., Tel: 410-221-8425, Fax: 410-221-8490, E-mail: roman@hpl.umces.edu and ²College of Oceanic and Atmospheric Sciences, Oregon State University, Corvallis, OR 97331, U.S.

Relationships between meszooplankton biomass, primary production and vertical flux: A synthesis of oceanic data

Mesozooplankton, through their production of rapidly (> 200 m d^-1) sinking fecal pellets, have the potential to influence the vertical flux of particulate material. Realization of this potential depends on multiple factors such as the abundance and species composition of the mesozooplankton community, hydrographic properties of the euphotic zone, and the size structure of the phytoplankton community. Data gathered by oceanic programs that focused on biogeochemical cycles such as JGOFS and VERTEX provide a range of study conditions which can be used to assess the potential relationships between mesozooplankton and the vertical export flux of particulate material. We have begun a synthesis of this oceanic data at sites where horizontal transport of particulate material is presumed to be minimal and thus processes within the euphotic zone determine the rates of vertical flux. We will present results from our initial efforts based on the results of the U.S. JGOFS program and process studies from the VERTEX program to examine relationships between vertical flux and mesozooplankton in a variety of latitudes, mixed layer depths and rates of primary production. In presenting this data we hope to enlist the collaboration of other scientists who would like to join our effort. Relevant parameters in this synthesis effort include: hydrographic properties of the euphotic zone, chlorophyll (size fractions, if available), primary production, new production, mesozooplankton biomass (size fractions, if available), fecal pellet production and the vertical flux of particulate material.