Cyanobacteria in the Finger Lakes, New York; Nutrient Sources for Shoreline Blooms.

Session: Finger Lakes Water Quality (1)

John Halfman, Hobart & William Smith Colleges, Geoscience/Environmental Studies Program, [email protected]
Roxanne Razavi, SUNY College of Environmental Science and Forestry, [email protected]
Trevor Massey, Finger Lakes Institute, Hobart & William Smith Colleges, [email protected]
Lisa Cleckner, Finger Lakes Institute, Hobart and William Smith Colleges, [email protected]
Dana Hall, Owasco Watershed Lake Association, [email protected]
Rogers Peter, Owasco Watershed Lake Association, [email protected]

Abstract

Cyanobacteria (or blue green algae, BGA) have increasingly influenced waterbodies throughout the globe.  Since 2012, an increasing number of Finger Lakes (FLs) in central New York have experienced sporadic, shoreline hugging, BGA blooms, even though ten of the eleven FLs are oligotrophic/mesotrophic systems.  Here, we present limnological data from the eight eastern FLs to investigate potential triggers for BGA blooms.

Since 2005, monthly water quality monitoring of the eight eastern FLs during May – October using at least 2, mid-lake, deep-water sites in each lake have revealed decreasing Secchi depths, and increasing phosphorus (TP, SRP), turbidity (TSS), and chlorophyll concentrations over time.  Survey specific spikes in TSS are associated with huge convective and localized storms typically coincided with or precede the onset of BGA blooms in each lake.

Weekly water quality surveys of offshore, nearshore (~3m) and dockside sites in Owasco Lake coupled with buoyed meteorological data indicate that the shoreline BGA blooms were typically preceded by dips in surface water temperature, increased wind speeds, decreased light intensity, and typically a rain event; then emerged under calm and sunny conditions.  Lab experiments suggest that disturbed sediments can release sufficient nutrients and resting stage cells to support bloom development.