The two most important items to watch are temperature and blue-green algae levels. Once water temperatures hit the high 60s, we’ll be in the blue-green algae danger zone. And then you can simply track the blue-green algae levels. Each sensor is slightly different on the blue-green algae scale, but in general, levels above 10 – 12 ug/L are probably within the bloom / danger range.
The buoy website enables graphs and data over a period of time to be viewed. Click on the blue box labeled “Lake Agawam Buoy” in upper left hand corner. Then choose the parameter you wish to view. See how the Lake has changed since the buoy was installed on May 22, 2020.
Key parameters
Blue Green
Blue green algae or cyanobacteria manufacture their own pigment, phycocyanin, and when present in high amounts gives the water a light green opaque quality. Buoy readings of blue green algae over 3 ug (micrograms)/liter are considered a “bloom.”
Salinity
Lake Agawam is a freshwater body and its salinity is typically between .03 and .04. Salinity is measured in Practical Salinity Units (psu).
- Freshwater = 0 psu
- Brackish = 5-7 psu
- Saltwater = 15-32 psu
pH
pH measures the acidity or alkalinity of a substance. pH measurements range from 0-14.
0 = highly acid (battery acid)
7 = neutral
14 = highly alkaline (lye)
The pH range on Lake Agawam is usually in the 7 to 10 pH.
Chlorophyll
Chlorophyll is the pigment manufactured by plants & phytoplankton that is responsible for photosynthesis (the manufacturer of organic carbon from C0² gas & sunlight). More chlorophyll pigment in the water means that there is more algae and phytoplankton. The levels of chlorophyll in the water at Lake Agawam vary widely seasonally and daily and is measured in micrograms (ug)/liter. High levels of chlorophyll in the water often turn the water a dark green or brown color.
Dissolved Oxygen
Almost all life needs oxygen to survive. Dissolved oxygen is the measure of the amount of free oxygen molecules in water. The New York State DEC standard for surface waters is ideally 5 (milligrams)/liter and never less than 3 mg (milligrams)/liter. Depending on environmental conditions the water in Georgica Pond can range from 0 mg/liter (anoxic, which cannot support life) to 18 mg/liter. Dissolved oxygen is added to water through photosynthesis of aquatic plants and directly from the atmosphere. Dissolved oxygen levels in the pond peak during daylight and decline at night. As organisms breath and organic matter decays, dissolved oxygen is depleted.
Temperature
Most of us think in Fahrenheit, so to help you interpret the Celsius temperature data remember that:
0°C = 32°F
During the summer months, the pond water can reach 21°C or 70° F.
The calculation is as follows: 70°F = 21°C x 9/5 + 32
Temperatures above 20°C are conducive to algal blooms.
