Long Island Sound has reached a historic milestone in water quality, with low-oxygen conditions at its lowest levels since 1987.
Hypoxia refers to low oxygen levels in waters near the sea floor, making affected areas uninhabitable for fish and other marine life. It can happen when there is excessive nitrogen in the water, which comes from stormwater runoff and wastewater.
A study from the Connecticut Department of Energy and Environmental Protection found hypoxia covered only about 18 square miles of the Sound at the maximum. That number is down from 43 in 2024 and 127 in 2023.
“This year’s historic decrease in hypoxia illustrates 40 years of amazing progress through the Long Island Sound Partnership,” said EPA Region 2 Administrator Michael Martucci in a statement. “Dedicated efforts and investments by EPA, Connecticut, New York, and local governments have drastically reduced the amount of nitrogen pollution entering the Sound, resulting in smaller affected areas and fewer days of low oxygen.”
The Long Island Sound Partnership, which includes DEEP and the EPA, has also released a Hypoxia Forecasting Model and Toolkit to help folks better understand what’s happening below the surface.
They say the best ways for residents to help include reducing fertilizers, picking up after their pets, and clearing debris near storm drains.
