Reactions that take place at the sediment-water interface and within the sediment column under oceanic regions of high productivity significantly affect the global budgets of nitrogen, oxygen, carbon, and silica. The Principal Investigators have been successful in using in situ benthic flux chambers to directly measure fluxes of these elements and have described their cycling within the basins of the southern California borderland. They are proposing to continue this type of work by: (1) building individual flux chambers for use with the submersible Alvin in order to directly study the effects of the disturbance from chamber deployment to the sediment-water interface on benthic exchange rates; (2) deploying landers in Santa Monica Basin in order to measure nitrate uptake rates that will enable us to confirm estimates of the rates of oxygen and nitrogen cycling in these coastal sediments. The purpose of building individual chambers is to perform manipulative experiments with the aid of Alvin and quantify the relationship between disturbance to the sediment-water interface and benthic exchange rates. This will establish an accurate value for benthic exchange of nitrogenous compounds, silica, oxygen and carbon species.
