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11/18/21: Silvia Newell
November 18, 2021 @ 2:00 pm - 3:00 pm
Please join us for a Virtual Great Lakes Seminar Series presentation:
Time: 2:00-3:00 pm EST
Presenter: Silvia Newell – Associate Professor, Wright State University
Title: Nitrogen availability as a driver of HABs and toxins: the missing piece for modeling?
About the presentation: External nutrient loading (along with temperature and precipitation) is the main driver of annual harmful algal blooms in Lake Erie. These blooms are dominated by the cyanobacteria Microcystis, which produces microcystin toxins, but toxicity and biomass are not always correlated and can vary from year to year and within a season. Microcystis is an excellent scavenger for ammonium and can outcompete other organisms for this preferred ammonium supply. Ammonium is therefore both taken up by cells and recycled rapidly in eutrophic systems, making it difficult to determine availability snapshot concentration measurements. Studies on ammonium turnover rates in the water column of Lake Erie, as well as supply from sediments, suggest that internal loading is a critical component of sustaining bloom biomass. Using ammonium recycling rates in mixed models also results in strong models for concentration of microcystins (R^2 =0.84 or better), suggesting that ammonium availability might be key for modeling and predicting bloom toxicity.
About the speaker: Dr. Silvia Newell is an Associate Professor of Aquatic Biogeochemistry at Wright State University in Dayton, OH. Her research focuses on nitrogen cycling in eutrophic systems around the globe, from the Great Lakes to Lake Okeechobee to Taihu, China. She was the co-chair of the HABs Collaborative from 2018-2020 and currently serves as the President of the Lake Erie Area Research Network. She is currently NSF-funded on projects in Lake Superior, Lake Erie, and the Maumee River. She is also part of the monitoring team assessing the H2Ohio wetlands.
**Registration is not required**