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Long Island Sound Sees Significant Reduction in Dead Zones Following $2.5 Billion Cleanup Effort

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Published on December 27, 2025
Long Island Sound Sees Significant Reduction in Dead Zones Following $2.5 Billion Cleanup EffortSource: Wikipedia/Theeditor93, CC BY 3.0, via Wikimedia Commons

The Long Island Sound, a vital estuary stretching over nearly 1,200 square miles between New York and Connecticut, has witnessed a significant environmental triumph, with local environmental groups noting the smallest presence of dead zones since monitoring commenced in 1987. This improvement signals a rebounding marine ecosystem where, as Peter Linderoth, director of healthy waters and lands for Save the Sound, stated, "fish and other organisms would literally suffocate in the water because there wasn’t enough oxygen" during the 1980s due to severe hypoxia caused by nitrogen pollution, according to a Gothamist report.

In a coordinated effort spanning two decades, federal and state agencies have invested $2.5 billion in upgrading sewage plants to reduce nitrogen discharge, resulting in the dramatic shrinkage of dead zones to just 18 square miles, and Michael Martucci, Environmental Protection Agency Region 2 administrator, acknowledged the dedicated efforts resulting in fewer days of low oxygen, the Gothamist reports. However the battle against pollution is far from over, with stormwater runoff and septic tanks still contributing significantly to nitrogen pollution, and the evolving challenge of climate change, which can reduce water oxygen levels further due to warming.

Complementing these efforts, the Long Island Sound Futures Fund recently awarded nearly $12 million in grants for projects aimed at improving water quality, managing stormwater, restoring habitats, and reducing nitrogen pollution across the Sound's watershed, which spans across five states, as per an announcement detailed in a CT Mirror article. These grants represent a collaboration between the National Fish and Wildlife Foundation, the U.S. Environmental Protection Agency, and other state and federal agencies, combining public and private funding sources for the betterment of the estuary and its surrounding ecosystems.

Despite recent shifts at the EPA, including the closure of their Long Island Sound Office in Stamford and a general reduction in staff and funding nationally, the grants and projects continue uninterrupted, highlighting resilience in advocacy and environmental stewardship for Long Island Sound, Bill Lucey of the nonprofit group Save the Sound expressed in a statement obtained by CT Mirror, underscored by the growth of the EPA program's funding to $40 million in the recent fiscal year, up from a modest $1 million a decade ago, demonstrating a sustained commitment to the sound's wellbeing despite broader agency challenges.