Year Established: 2016 Start Date: 2016-03-01 End Date: 2018-02-28
Total Federal Funds: $15,480 Total Non-Federal Funds: $31,599
Principal Investigators: Tracy Quirk, Kanchan Maiti
Abstract: Small streams and bayous are important surface water features in south Louisiana, connecting larger freshwater rivers and lakes to coastal bays and estuaries. These freshwater systems also serve as sources of water for public supply, and industrial and agricultural use. However, nutrient and organic loading, hydrologic alterations, and an increase in aquatic floating plants in slow-flowing streams and bayous may result in periodic to chronic hypoxia having negative consequences on aquatic organisms. While hypoxia in coastal waters and estuaries is relatively well documented, less is known about the extent and mechanisms of hypoxia in smaller freshwater systems. The proposed research is focused on assessing the spatial extent of inland hypoxia in low-flow streams and bayous across south Louisiana, examining temporal variability in hypoxia and related parameters in a subset of waterways, and determining the proximal mechanisms of hypoxia by examining biological oxygen demand of sediments and water column and the influence of particulate and dissolved carbon sources. Intensive studies are proposed to examine differences in oxygen and carbon dynamics in forested versus open channels. An initial survey of dissolved oxygen, temperature, pH stream flow, and turbidity of twenty-five streams and bayous across south Louisiana will be conducted. Temporal oxygen dynamics will be monitored over one year in two contrasting stream-types: a forested stream and an open bayou with over 60% coverage of nuisance floating aquatic vegetation. Lastly, sources and forms of carbon contributing to hypoxic conditions will be determined through laboratory biochemical oxygen demand incubations. The results of this study will aid in development of a strategy to minimize low oxygen conditions, which may vary across locations, depending on site-specific conditions leading to hypoxia.