1. Total bottom stress as a potential predictor of Microcystis resuspension in the western basin of Lake Erie.
- Author
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Galvan, Journ, Habib, Joshua, Beletsky, Raisa, and Beletsky, Dmitry
- Subjects
MICROCYSTIS ,WATERSHEDS - Abstract
Previous studies have shown that the western basin of Lake Erie is prone to sediment resuspension due to its shallow depth and abundance of fine-grained sediments. Harmful algal blooms (HABs) caused by the bacteria Microcystis are also common in the western basin and have been shown to overwinter in the sediment layer. Total bottom stress combines shear stress caused by both waves and currents and is the most crucial factor influencing sediment resuspension. Our study utilized hindcasts of hydrodynamic models, specifically WAVEWATCH III (WW3) and Finite Volume Community Ocean Model (FVCOM), to calculate total bottom stress in the western basin of Lake Erie in May-October, 2017-2019. Results showed that wave-induced bottom stress dominated in the western basin, while current-induced bottom stress was smaller but could still cause resuspension during peak events. The highest total bottom stress values were associated with shallow waters (less than 5 m), which included the Maumee Bay and Detroit River mouth. Total bottom stress also varied seasonally, with the most significant values occurring in May and September-October and across years (2019 was less energetic than 2017 and 2018). Future work for this study will seek to identify resuspension events when total bottom stress exceeds the critical shear stress to move the sediment. Calculated bottom stress from WW3 and FVCOM models will also be tested as a potential predictor in retrospective statistical modeling to improve current HAB forecasts in Lake Erie. [ABSTRACT FROM AUTHOR]
- Published
- 2023