Comparing dissolved oxygen sensors and developing design criteria for mobile platform monitoring of hypoxia

ENVR 46

Rex A. Mann, rmann@serf.tamus.edu, James S. Bonner, Temitope O. Ojo, and Shahidul M. Islam. Civil Engineering Department, Texas A&M University, 3136 TAMU, WERC 205, College Station, TX 77843
In the summer months, the water column in parts of Corpus Christi Bay (Texas, USA) becomes stratified which can lead to hypoxia. Hypoxia is the condition where the concentration of dissolved oxygen (DO) drops below 2 mg/L and most aquatic organisms cannot survive in this condition. Our research group uses mobile platforms (i.e., a research vessel pulling an undulating tow-body with sensors) to capture hypoxia and further our understanding of it. DO sensors with a response time on the order of ten seconds are needed in order to sufficiently capture the water column using the mobile platforms. In this paper, electrode and optical sensors are compared and tested for their response time and design criteria for DO sensors with this application is developed. Optical DO sensors significantly outperform electrode sensors with respect to response time and, because of this advantage and others, we recommend their use for mobile platform applications.