Water samples were collected on Tuesday, Aug. 27 from both mid-lake/open water and shoreline locations for Total Microcystins analysis. Results are provided below for informational purposes; the BFS is not an ELAP-certified laboratory.
Background Information: Cyanobacteria, or blue-green algae, can produce compounds that are toxic to humans, pets, and livestock. Microcystis aeruginosa is the cyanobacteria currently causing intermittent bloom conditions in Otsego Lake; toxins of the class Microcystins have been detected in association with its growth (learn more here: https://www.epa.gov/…/learn-about-harmful-algae…). We have received questions about the toxin concentrations we report and what they mean; explanation of Dept. of Health, Dept. of Environmental Conservation and US EPA guidance are included below. See the respective agency websites for complete information.
In summary: Isolated shoreline bloom conditions were reported several days this week, forming later in the afternoons at locations along the western shore and north end of Otsego Lake. Toxins are present lake-wide (open water and near shore) and have increased slightly since last week in most areas, reflecting the continued growth of the cyanobacteria in the surface layer of the lake. General precautions are given below. If you see suspicious conditions, report it to the NYS Dept. of Environmental Conservation HABs Program via the online report tool.
Results Update: Total Microcystins in micrograms per liter, or parts per billion (ppb)
Open Water (Mid-Lake) Sites
Tuesday, August 27, 2024
Site & Depth
MC (µg/L)
Near Data Buoy (TR4-C) Surface
0.51
– 4m / 13 ft
0.42
– 8m / 26 ft
0.26
West of Hyde Bay (TR5-C) Surface
0.54
Shoreline Sites
Tuesday, August 27, 2024
MC (µg/L)
Fairy Springs Swim Dock
0.60
Lakefront Village Dock End
0.20
Cooperstown Country Club Dock
– –
BFS Main Lab
– Dock End
0.22
– Dock, South side
0.30
Three Mile Point Swim Dock
– –
Otsego Sailing Club
– Swim Dock, South side
0.42
– Swim Dock, North side1
0.50
5 Mile Point
– Dock, East end
0.27
– Between shore & docks
0.22
BFS Thayer Boathouse
– Dock End
0.43
– Slight Surface Accumulation
0.43
Springfield Public Landing
– Swim Dock
0.27
– Shoreline debris patch2
0.32
1surface debris and foam
2patch brown; seems to be dead Microcystis
Analytical Method: Total Microcystins ELISA (ADDA) via CAAS Cube, according to EPA Method 546. Method detection limit 0.1 µg/L.
General Precautions:
Avoid discolored or cloudy water, green streaks, foamy accumulations, etc., as these areas may contain cyanobacteria and the associated toxins. Pets are particularly vulnerable. Lake users should use caution and check the water conditions prior to use, as bloom conditions are known to change quickly. Keep watch along the shoreline and at the surface in protected areas (boat slips, small coves, etc.). Do not use untreated surface waters for domestic use; during blooms, surface waters treated with individual home treatment systems should not be used for domestic use (see the Dept. of Health page https://www.health.ny.gov/publications/2849/index.htm).
Perspective on Toxin Concentrations: Total Microcystins Guidance
Recreational Contact: In New York State, Regulated Swimming Beaches are closed based on visual indication of a bloom and can be re-opened after the bloom has dissipated (visual assessment) and the total microcystin concentration is less than 4 µg/L in a sample collected the following day. Link to Dept. of Health Bloom Response and Regulated Beaches page.
Drinking Water Health Advisory Levels for Microcystins (Based on US EPA Guidance).
Adverse health effects are not anticipated to occur over 10-day exposures when concentrations in drinking water are less than:
-Bottle-fed infacts & pre-school children: 0.3 µg/L
-School-age children and adults: 1.6 µg/L
For More Information:
NYS Dept. of Conservation Harmful Algal Blooms Page: https://dec.ny.gov/…/water-quality/harmful-algal-blooms
NYS Dept. of Health:https://www.health.ny.gov/publications/2849/index.htm
US Environmental Protection Agency Harmful Algal Blooms Page:https://www.epa.gov/habs
Holly Waterfield, CLM
SUNY Oneonta Cooperstown Campus
Biological Field Station Main Laboratory
5838 State Hwy 80
Cooperstown, NY 13326
607-547-8778