Abstract: Flowing waters are drastically impacted by land use change and the introduction of pollutants. Once considered mere conduits of plastic transport, streams are biogeochemically active, and capable of transporting and transforming natural and anthropogenic litter as it moves between terrestrial and marine ecosystems. Plastic pollution, in particular, is ubiquitous and an important component of the urban carbon (C) budget in streams. However, plastics are rarely included in our depictions of the C cycle. Streams and rivers are key features of the C cycle with major impacts on the retention, transformation, and movement of plastics and other sources of C to downstream ecosystems. In the environment, plastic is rapidly colonized by microbial biofilms, and thus, can potentially alter biogeochemical processing of nitrogen, phosphorus, and other forms of C. Despite a growing understanding of plastic distribution and transport in the environment, the role of plastic, a recalcitrant C-based polymer, on the broader C cycle and other important biogeochemical processes (e.g., stream metabolism) is rarely quantified. The overarching theme of my proposed research program is to quantify the relative importance of plastic in ecosystem C budgets, and to determine the landscape-scale and hydrologic variables that drive and predict plastic-C transport, storage, and processing in streams. Because urban streams are tightly coupled to human activity, studying plastic pollution, C cycling, and their interaction is needed to understand fundamental aspects of ecosystem function (e.g., metabolism).

Bio: Dr. Anna Vincent is a biogeochemist and ecosystem ecologist, and is currently a postdoctoral scholar with the Northwestern-Argonne Institute of Science and Engineering. Her current work is focused on understanding how green infrastructure and nature-based solutions can help to mitigate the impacts of heat waves and intense flooding in cities. She is also contributing to the ongoing SmartWater study, which seeks to identify pollution hot spots and hot moments in urban streams, and explores how low-cost high-frequency sensors can be used to track pollutant transit over space and time. She completed her PhD at the University of Notre Dame under the direction of Dr. Jennifer Tank where she assessed controls on inorganic Nitrogen cycling and changes to stream metabolism following storms in agricultural streams. Prior to attending Notre Dame, she obtained a Master's degree from Loyola University Chicago where she characterized microplastic transport in urban streams using classical stream spiraling metrics and assessed the effects of plastic pollution of microbial community composition. As her postdoctoral appointment nears its end, Anna is actively applying for tenure-track faculty positions, and in today's seminar, Anna will be providing an overview of her past and current work, and work that she proposes to conduct in the future.