EARLY HEARING DETECTION AND INTERVENTION VIRTUAL CONFERENCE
MARCH 2-5, 2021
(Virtually the same conference, without elevators, airplane tickets, or hotel room keys)
5/21/2018 | 9:45 AM - 10:00 AM | WESTERN LAKE ERIE WATER COLUMN AMMONIUM: INTERNAL CYCLING, SEASONAL DYNAMICS, AND HARMFUL CYANOBACTERIAL BLOOMS | 420 B
WESTERN LAKE ERIE WATER COLUMN AMMONIUM: INTERNAL CYCLING, SEASONAL DYNAMICS, AND HARMFUL CYANOBACTERIAL BLOOMS
Cyanobacterial harmful algal blooms (HABs) in western Lake Erie are largely driven by agricultural nitrogen (N) and phosphorus from the Maumee River watershed. Cyanobacterial dominance and HAB development may be co-dependent on ammonium availability, and increased ammonium has been linked to toxin production. In 2015, 2016, and 2017, 15N tracers were used to quantify rates of ammonium regeneration and potential uptake, ammonia oxidation to nitrite (the first step of nitrification), and total nitrification along a transect in the western basin of Lake Erie. Ammonia oxidation and total nitrification rates were comparable to coastal ocean rates. However, nitrification rates were several orders of magnitude lower than total community ammonium uptake rates, indicating that ammonia oxidation and nitrification are not the dominant uptake pathways. During non-bloom months, regeneration rates could account for an average of 80% of potential community uptake, but during the height of the bloom, when community ammonium demand was much greater, regeneration could only support 40% of potential uptake. These results suggest that management of external total N loads, which are readily converted to ammonium, may be necessary to reduce bloom biomass and toxin concentration.
- Great Lakes
- Nitrogen
- Eutrophication
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Presenters/Authors
Daniel K. Hoffman
(), Wright State University, dprhoffman@gmail.com;
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Mark McCarthy
(), Wright State University, mjm.kingston@gmail.com;
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Timothy W. Davis
(), Bowling Green State University, timdavi@bgsu.edu;
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Duane Gossiaux
(), NOAA Great Lakes Environmental Research Laboratory, duane.gossiaux@noaa.gov;
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Ashley Burtner
(), Cooperative Institute for Great Lakes Research, aburtner@umich.edu;
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Tom Johengen
(), Cooperative Institute for Great Lakes Research, tom.johengen@noaa.gov;
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Danna Palladino
(), Cooperative Institute for Great Lakes Research, danna.palladino@noaa.gov;
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Wayne S. Gardner
(), The University of Texas Marine Science Institute, wayne.gardner@utexas.edu;
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Justin A. Myers
(), Wright State University, justin.meyers@wright.edu;
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Silvia E. Newell
(), Wright State University, silvia.newell@wright.edu;
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