Water Quality Impact of the 2017 St. Lawrence River Flood Compared to Years 2014-2016

Session: 30. - Ecosystem Impacts of the Lake Ontario-St Lawrence River Flood of 2017

Michael Twiss, Clarkson University, Dept. of Biology & Great Rivers Center, [email protected]
El-Amine Mimouni, St. Lawrence River Institute for Environmental Sciences, [email protected]
Jeff Ridal, St. Lawrence River Institute, of Environmental Sciences, [email protected]
Joseph Skufca, Clarkson University, [email protected]

Abstract

High resolution water quality sensors (YSI &Turner Cyclops 6) were installed in the Moses-Saunders hydropower dam to measure nearshore and main channel water quality.  The sensor array closest to the NY shore has been in place for the longest duration (June 2014 to present).  Thus, a record of high resolution water quality measurements (1 minute intervals) is available to compare nearshore water quality before, during and after the extreme water levels encountered in the Saint Lawrence River in 2017.  These observations can help support adaptive management strategies since they show changes in water quality that can be related to ecosystem impacts over compressed time scales compared to the proposed ecosystem performance indicators to assess management to achieve more natural water level management (Plan 2014), such as northern pike recruitment and muskrat den density.  Data show the flux of phytoplankton and nutrients (P, N, Si) downstream during spring freshets and the summer 2017 flood and the change in phytoplankton community composition as determined by size fractionated chlorophyll-a and pigment specific fluorometry (bbe FluoroProbe). Additional measurements include temperature, colored dissolved organic matter, turbidity and phycocyanin.  Data archives from this sampling array support adaptive management initiatives to restore the St. Lawrence River ecosystem.

1. Keyword
water quality

2. Keyword
Water level

3. Keyword
water level fluctuations

4. Additional Keyword
phytoplankton

5. Additional Keyword
nutrients

6. Additional Keyword
St. Lawrence