A precise predictive model is needed to obtain a clear understanding of the changing dissolved oxygen content in outdoor crab ponds, to assess how to reduce risk and to optimize water quality management. The uncertainties in the data from multiple sensors are a significant factor when building a dissolved oxygen content prediction model. To increase prediction accuracy, a new hybrid dissolved o...

Nutrient concentration profiles are affected by the mass transport outside the biofilm, inside the biofilm, and by the structure of the biofilm. To understand the distribution of biofilm activity, it is necessary to correlate the local nutrient concentration, local mass transport in the biofilm and the biofilm structure. The correlations among surface averaged dissolved oxygen concentration, su...

A screen-printed dissolved oxygen sensor was fabricated using cerium oxide-supported silver catalyst and polydimethylsiloxane (PDMS) film. A PDMS film of 3 µm thickness showed good permeability for oxygen and impermeability for hydrogen peroxide. The calibration curve has shown a linear relationship with a correlation coefficient of 0.996 for the dissolved oxygen concentration. The sensitivi...

We present a low-cost sensor buoy designed for unattended dissolved oxygen measurement in aquatic environment. We describe the buoy’s architectural design and three experiments that we carried out to demonstrate its viability: a laboratory test in a water tank with controlled oxygen level, a lake deployment and an extensive electric power consumption test. Our experiments indicate the viability...

Hypoxia conditions are increasing throughout the world, influencing biogeochemical cycles of elements and marine life. Hypoxia results from complex interactions between physical and biogeochemical processes, which can not be understood by observations alone. Models are invaluable tools at studying system dynamics, generalizing discrete observations and predicting future states. They are also us...

Population level response to hypoxia has become an issue of global significance because of increased frequency and intensity of hypoxic events worldwide, and the potential for global warming to exacerbate hypoxic stress. In this study, we sequenced two nuclear intronic regions and a single mitochondrial region across seven populations of the African cyprinid, Barbus neumayeri from two river dra...