Protecting & Restoring Long Island's Peconic Bays
PEP works with a number of partners to monitor the condition of water quality and essential habitats in the Peconic Estuary.
Water Quality Monitoring>>>
Atmospheric Deposition Monitoring>>>
Salt Marsh Surface Elevation Table (SET) Monitoring>>>
Water quality monitoring is essential in order to assess the health of the Peconic Estuary and to help determine if management goals are being reached. The Peconic Estuary Partnership supports both a year-round long-term periodic sampling program conducted by the Suffolk County Department of Health Services (SCDHS) Office of Ecology, Bureau of Marine Resources and a continuous sampling program conducted by the United States Geological Survey (USGS). These two water quality sampling programs complement each other and together provide a great resource for understanding the Peconic Estuary.
SCDHS’s water quality sampling provides excellent spatial coverage of the estuary and its freshwater tributaries and the high frequency data collected at the USGS continuous monitoring stations provide excellent temporal coverage at two sites.
Monitoring is essential in order to assess the health of the Peconic Estuary and to help determine if management goals are being reached.
Suffolk County Bureau of Marine Resources has routinely monitored the water quality of surface and marine waters in the Peconic Estuary since 1977. On a monthly basis, 38 marine locations in main bays and peripheral embayments, and an additional 26 stream and point source sites in the Peconic Estuary are sampled from boats or from shore to assess status of the Peconic Estuary. These data are sufficient to document seasonal variability and trends in the waterbodies being measured.
Sampling of marine and fresh surface waters, and a number of area point sources (STPs), was initially conducted by the Suffolk County Bureau of Marine Resources (BMR) in 1976 under the federally funded Long Island Comprehensive Waste Treatment Management Plan (LI 208 Study). Monitoring efforts have continued since that time, but have varied in frequency, the degree of spatial extent and the parameters analyzed, depending on the needs of existing programs and available resources.
Sampling analytes at marine stations include total and dissolved nitrogen and phosphorus, dissolved inorganic nitrogen (nitrate, nitrite and ammonia), dissolved ortho-phosphate, total and fecal coliform bacteria, total suspended solids, chlorophyll-a, and the brown tide organism Aureococcus anophagefferens. Physical measurements taken include salinity, temperature, dissolved oxygen, pH, light (PAR) attenuation and secchi depth. Fresh water samples are also analyzed for dissolved metals and numerous organic constituents, including volatile organic compounds, semi-volatile organic compounds, pesticides and herbicide compounds.
All Suffolk County Department of Health Services Water Quality Data and Information is available here.
In 2012, the Peconic Estuary Partnership and Suffolk County partnered with the United States Geological Survey (USGS) to install two continuous monitoring stations in the Peconic Estuary, one located at the mouth of the Peconic River under the County Road 105 bridge in Riverhead and one in Orient Harbor. These two monitoring stations complement the periodic sampling conducted by SCDHS by providing continuous sampling of the water quality conditions within the estuary.
At 6 minute intervals, ocean and estuary elevation, water temperature, specific conductivity, salinity, dissolved oxygen, turbidity, chlorophyll, sampling depth and pH are measured. A nitrate analyzer measures nitrate in the water column every 30 minutes.
High frequency measurements of key water quality parameters allow long-term trend assessment of climate and other incremental changes. Moreover, estimates of frequency, severity, and duration of hypoxia (low oxygen conditions) and anoxia (zero oxygen conditions) have been collected using the two USGS continuous monitoring stations since 2012. This information was particularly helpful to figure out the reasons for the 2015 fish kill in the
Peconic River because the dissolved oxygen concentrations were recorded every 6 minutes and captured the times when dissolved oxygen was at levels too low to sustain aquatic life.
All USGS data is publically available in near-real-time and posted on the USGS website:
USGS Continuous Monitoring at Riverhead, NY
USGS Continuous Monitoring at Orient, NY
Nitrogen cycles from the air to the land and water through atmospheric deposition. Since 2003, the Peconic Estuary Partnership has been monitoring the atmospheric deposition of nitrogen in the Peconic Estuary watershed, through our participation in the National Atmospheric Deposition Program. The program collects data and trends about the deposition of Ammonia (NH3), a gas readily released into the air from a variety of biological sources, as well as from industrial and combustion processes, and other components in precipitation. This monitoring is essential to understanding the amount of nitrogen entering the estuary through atmospheric deposition and helps inform nitrogen management policies and goals.
Conducted by Suffolk County Department of Health Service Bureau of Marine Resources. Weekly monitoring at the National Atmospheric Deposition Program (NADP) rain and atmospheric deposition gauge at Cedar Beach, Southold, NY.
National Atmospheric Deposition Program Station Data and Information
PEP works with a number of partners to monitor the condition of essential habitats in the Peconic Estuary.
Since 1997,Cornell Cooperative Extension of Suffolk County has monitored of eelgrass survival and bed expansion resulting from previous habitat restoration efforts. Long-term measurements of seagrass extent and deep edge location at historical sites, measurements of light, temperature, and sediment conditions at these sites have been documented and the Peconic Estuary Partnership Long-Term Eelgrass Monitoring Program (PEP LTEMP) report has been produced every year. Currently, CCE conducts long-term monitoring at thirteen sites within the Peconic Estuary. Nine of those sites are monitored annually, and four of those sites, that no longer support eelgrass, are monitored every 2-3 years.
Eelgrass monitoring program measures: below-ground and above-ground biomass (lab analysis), water temperature, sediment samples (lab analysis for percent organic content), fauna counts, light measurement, salinity, macroalgal percent cover and identification, eelgrass bed aerial extent, eelgrass shoot density. Additionally, temperature and light loggers are deployed for extended periods of continuous sampling during the growing season.
Peconic Estuary Partnership measures the surface elevation of the salt marsh at Indian Island County Park. There are six surface elevation tables at the site to measure marsh accretion or subsidence, natural processes that may be influenced by sea-level rise, changes in sediment loading, increasing temperatures, and other consequences of climate change. Monitoring is conducted twice annually, once in the spring and once in the fall.