Real-Time Data


Water Quality Buoy USGS Pond Gauge
The real-time water quality buoy was first installed in Georgica Pond in 2015. A project of the Gobler Lab at the Stony Brook University School of Marine & Atmospheric Sciences (SOMAS) the buoy allows us to understand daily and yearly changes in the basic ecological parameters of the pond. Some of these changes have a direct effect on the water quality of the pond including harmful algal blooms. The water quality buoy is funded by FOGP. The real-time pond level gauge allows us to immediately see changes in the height of the pond in relation to sea level. It operates via telemetry 12 months/year. The gauge is owned and maintained by the United States Geological Survey (USGS) and funded by a four-year funding partnership (started in 2017) including the USGS, the Village of East Hampton and FOGP.

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”. When confirmed via ‘grab samples’ the NYSDEC and/or Suffolk County and/or the Town Trustees may declare Georgica Pond unsafe for swimming, crabbing and fishing.


Georgica Pond is usually in the brackish range of salinity—somewhere between freshwater and saltwater. When the pond is open to the ocean, it can reach saltwater salinities. Salinity is measured in Practical Salinity Units (psu).

  • Freshwater = 0 psu
  • Brackish = 5-7 psu
  • Saltwater = 15-32 psu


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)

Saltwater and brackish water such as Georgica Pond are usually in the 7-9 pH range.


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 Georgica Pond 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.


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.