Rivers and streams provide important services, such as drinking water, fisheries, and recreational opportunities. Yet, the integrity of rivers and streams throughout the globe is compromised by pollution from aging and obsolete wastewater infrastructure. Currently, there is limited understanding of how human waste affects stream communities and ecosystem processes. The project will integrate field observations, experiments, and modelling, to advance our understanding of how rivers and streams are affected by wastewater infrastructure, and will provide new insights into interactions between civil and environmental engineering and ecosystem science. This CAREER award will support the training and development of high school students, graduate students, and a postdoctoral researcher.
Understanding the spatial and temporal variation in the factors influencing riverine structure and function is essential to predict how fresh waters will respond to continued anthropogenic change. This CAREER award will couple field observations with field- and lab-based experiments and modelling, to examine: 1) spatial and temporal variation in the quality, quantity, and relative volume of wastewater entering river systems, 2) the effects of wastewater on seasonal and annual patterns of metabolic processes flowing waters, 3) the influence of interactions between wastewater and ambient nutrient concentrations on trophic relationships and on the tissue and mineralization stoichiometry of consumers, and 4) the extent to which consumers transport wastewater-derived energy and elements to resource-limited systems within river networks. The award will integrate wastewater discharge into a spatial subsides framework to support more accurate predictions for how wastewater structures aquatic communities and alters biogeochemical processes in river networks. Moreover, the award will generate the data needed to compare seasonal and annual patterns in riverine metabolic processes in large, tropical rivers. The research will also test how flexibility in the trophic and stoichiometric traits of consumers governs the role they play in biogeochemical cycling under variable environmental conditions. Educational modules and service-learning projects in introductory environmental science and advanced ecology courses will be developed. High school students will be trained in stream ecology and provided internships with the local government and freshwater conservation organizations. Additionally, this research will have important management implications, as governments throughout the globe are challenged to fix wastewater effects on water quality, human health, and biodiversity.