Water column processes were examined in two environments within the continental margin of the northern Gulf of Mexico. Location I was at the shelf break and location II was at the inner to mid shelf. Each location was first characterized by a brief mapping exercise with the ship's flow-through monitoring system called MIDAS. This system monitors surface water conditions of temperature, salinity, chlorophyll fluorescence and light transmission. Each is plotted as a function of the ship's cruise track, providing a real time image of surface water properties. CTD profiles provided vertical resolution at selected sites. At each location, the information provided by the mapping output and CTD was used to select a location for deployment of a floating sediment trap array. At the slope location, traps were set at 65 m and 90 m. At the inner shelf station, traps were set for 17 m and 25 m. In both cases, water column processes in the vicinity of the drifting trap array were characterized over a 2 day deployment. During each trap deployment, depth profiles of temperature, salinity, chlorophyll and nutrient concentrations were made several times a day. Process measurements included phytoplankton primary production, P I properties and growth rate, bacterial production, water column respiration, microzooplankton grazing (2 methods), and mesozooplankton grazing (2 methods). At each location, additional water column measurements included: DOC profiles; quantification of dissolved carbohydrates; isolation and characterization of dissolved organic matter; phytoplankton pigments; irradiance profiles; and POC/PON. A budget of water column processes will be constructed at each of the two environmentally distinct deployment sites to determine carbon inputs, rates of recycling and fates within the upper water column. Published Non Refereed