The measurement of benthal oxygen demand in the Houston Ship Channel

A dredged canal is maintained from the entrance of Galveston Bay to the Port of Houston. O2 demand of benthal sediments is an important O2 sink in the Houston Ship Channel in Texas. A laboratory respirometer was designed to measure the rates of O2-depletion above a sediment sample. Design problems attending the high rates of O2 depletion were described and results of a pilot study of channel sediments are reported. Thirty respirometers were used, and their results correlated with a simple biochemical O2 demand (BOD) indicator test, to map the spatial distribution of benthal O2 demand in the channel. Use of the measured rates in a mathematical dissolved O2 model required consideration of the proper formulation of the benthal sink term in the model.