Friends of the Bay has been participating in the Unified Water Study (UWS) since it was first launched by Save the Sound in 2017. There are now 27 different organizations surrounding Long Island Sound in both NY and CT that are part of the UWS. As the name indicates, this is a unified approach to water quality monitoring where each group uses the same methods and equipment so that the data is comparable and more consistent. Funding for the UWS is made possible by a Long Island Sound Futures Fund grant awarded by National Fish and Wildlife Foundation. We participate in both tier 1 and tier 2 parameter collections.
Tier 1 Parameters:
Tier 2 Parameters:
Temperature
Salinity
Dissolved Oxygen
Turbidity
Chlorophyll a
Qualitative macrophytes
Vertical Divider
Continuous Dissolved Oxygen
Nitrogen
Phosphorous
Quantitative macrophytes
Information on these parameters and what they mean can be found below
Long Island Sound Report Card 2023 coming in 2024
Published every 2 years
Long Island Sound Report Card 2022
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But what does the data signify?
Dissolved Oxygen (DO) is required by all marine organisms. It fluctuates daily and seasonally as marine plants generate it during photosynthesis and marine animals consume it. Low oxygen is referred to as hypoxia and anoxia is defined as no oxygen. Low or no oxygen conditions can result from the decomposition of excess organic materials by microorganisms. The NYS Department of Environmental Conservation has determined that waters with DO below 3 milligrams per liter (mg/L) are hypoxic and uninhabitable for most marine organisms. DO between 2 and 4 mg/L can cause harm to many organisms with prolonged exposure. Levels below 1 mg/L are considered anoxic and usually fatal for organisms.
Salinity is a measure of the concentration of dissolved salts in water. For coastal waterbodies, it is measured in parts per thousand (ppt). Open ocean water is usually 30 to 35 ppt, whereas Long Island’s bays and inner harbors are usually 20 to 25 ppt. Many estuarine organisms tolerate a range of salinity, especially those that move around the estuary or live in the intertidal areas. Oysters are known to thrive over a wide range of salinity as do many of the bay’s fish species.
Temperature affects the growth, reproduction, and survival of marine organisms. Water temperature provides information on how much oxygen can be dissolved into the water, and dissolved oxygen is critical for the survival of marine animals and plants. Seasonal water temperatures, along with dissolved oxygen, are important indicators of habitat quality for species inhabiting the estuary. Temperature dictates what types of plants and animals can live there. Prolonged high summer temperatures can reduce oxygen leading to dangerously low levels (hypoxia), which can lead to harmful algal blooms and fish kills or even no oxygen (anoxia). Events such as reproduction, migration and feeding by estuarine species are based on temperature.
pH is an important indicator of water quality. It is a measure of the acidity or alkalinity of water. Estuarine pH levels generally range from 7.0 to 7.5 in those areas that are primarily freshwater. The ocean pH is 8.1, but estuarine pH can vary between 8.0 and 8.6. Measuring pH in Oyster Bay and Cold Spring Harbor is especially important as our bays support large populations of shellfish. The calcium carbonate shells of clams and oysters can thin when subject to lower pH. Ocean acidification has been cited globally as a growing problem for shellfish.
Turbidity is caused by the presence of particulate matter in the water that scatters light making the water appear cloudy. This particulate matter can include sediments such as silt or clay, microscopic marine organisms and organic or inorganic debris. Turbidity can affect water quality and the health of an ecosystem by limiting photosynthesis and ecological productivity below the surface, smothering spawning beds and reducing gill function in fish.
Chlorophyll a measures the amount of phytoplankton in the water column. These microalgae use nutrients within the Long Island Sound to grow. The general Long Island Sound range is between 0μg/l - 30μg/l.