Clean Waters and
Healthy Watersheds

Improve water quality by reducing contaminant and nutrient loads
from the land and the waters impacting Long Island Sound.

Learn More

Photo Credit Button Icon

A woman kayaks in the Black Hall River near the mouth of the Connecticut River in Old Lyme, Connecticut. Credit: Jerry Monkman/Ecophotography

Thriving Habitats
and Abundant Wildlife

Restore and protect the Sound’s ecological balance in a healthy, productive, and resilient state to benefit both people and the natural environment.

Learn More

Photo Credit Button Icon

Harp seal resting on beach in Madison, CT, waving flipper to warm itself in winter.

Sustainable and
Resilient Communities

Support vibrant, informed, and engaged communities
that use, appreciate, and help protect Long Island Sound.

Learn More

Photo Credit Button Icon

The mouth of the Saugatuck River in Westport, CT.

Sound Science and
Inclusive Management

Manage Long Island Sound using sound science and cross-jurisdictional
governance that is inclusive, adaptive, innovative, and accountable.

Learn More

Photo Credit Button Icon

UConn Professor Beth Lawrence collects data on surface water salinity with student Madeline Kollegger at a Barn Island tidal marsh. Photo by Emily Couture (CAHNR)/UConn.

The plan that guides Long Island Sound’s conservation is getting a major revision. Learn more.

The Long Island Sound Study (LISS) is a cooperative effort involving researchers, regulators, user groups and other concerned organizations and individuals. These people are working together to protect and improve the health of the Sound.

Learn More


The scientists dressed in waders pull a seining net onto the shore.
A brick building surrounded by green trees on pavement.
Photo of youth on a Rocking the Boat boat. Photo courtesy of Rocking the Boat
A middle-aged white women poses against a fence and smiles in a selfie taken next to a large pink flower.
Mollusks used in a research study assessing water quality impacts on the health of macrobenthic invertebrate populations.
Sound Spotlight

Palaeoecological Study Goes Back in Time to Assess Water Quality Progress in the Sound

Learn More

Long Island Sound
By The Numbers

Square Miles

Area of the Long Island Sound


Average Depth

18 trillion

Water Volume


Length of Coastline


Population Living Within 50 miles

Dollars (2015)

Estimated Value to the Local Economy Per Year


No. of Finfish Species Found in the Sound

Stay Connected

Sound Fact
Monitoring Water Quality on Long Island Sound with CT DEEP

Our Partners

Please complete your newsletter signup.