DEEP: LIS Water Quality & Hypoxia Monitoring Program

Long Island Sound
Water Quality Monitoring Program

The CT DEEP Water Monitoring Program, on behalf of the Long Island Sound Study estuary program, performs an intensive year-round water quality monitoring program on Long Island Sound. The data collected are used to understand the current conditions and changes in the water quality of the Sound.
{Photograph of the CT DEEP Long Island Sound monitoring vessel, The John Dempsey}
Program Background
Since 1991, CT DEEP has conducted an intensive year-round water quality monitoring program on Long Island Sound. From October to May, in situ data and nutrient samples are collected once a month from 17 sites.  Data from the surveys are used to quantify and identify annual trends and differences in water quality parameters relevant to hypoxia (low dissolved oxygen), especially nutrients, temperature, and chlorophyll. These data are also used to evaluate the effectiveness of the management program to reduce nitrogen concentrations.
During the summer (June -September) CT DEEP conducts additional summer hypoxia surveys at bi-weekly intervals to better define the areal extent and duration of hypoxia. During these surveys up to 48 stations are sampled for in situ parameters including dissolved oxygen, temperature, pH, and salinity.  Surface and bottom water samples are also collected and sent to a laboratory for analysis.

Since 2002, CT DEEP has collected zooplankton samples from 6 stations and phytoplankton from 10 stations across Long Island Sound. The samples are sent to researchers at the University of Connecticut who identify species composition, abundance, community structure, and spatial and temporal distribution throughout the Sound.

All samples are collected and analyzed under EPA-approved Quality Assurance Project Plans.
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Related DEEP Links

Sources of Additional Information

Contact Information
For questions or additional information please contact:
Chris Bellucci
Monitoring Program Supervisor
Bureau of Water Protection and Land Reuse
Connecticut Department of Energy and Environmental Protection
79 Elm Street, Hartford CT 06106

Long Island Sound General Information

Water Monitoring Program

Content last updated September 2019.