Long Island Sound Shows Signs of Ecological Comeback
A new report indicates significant improvements in water quality across the Sound, with the Western Narrows achieving its first passing grade in years.
The Long Island Sound is demonstrating signs of an ecological recovery, with water quality improving or remaining stable across all five of its open-water regions, according to the 2026 Long Island Sound Report Card released by Save the Sound.
The Western, Central, and Eastern basins each earned an "A" grade, while the Eastern Narrows received a "B." Notably, the Western Narrows, which encompasses the waters around New York City, achieved a "D," marking the first time this region has received a passing grade since Save the Sound began its grading in 2008. Previously, this area had consistently received an "F."
Further improvements were observed in other areas: the Western Basin moved up from an "A-" to an "A," and the Central Basin advanced from an "A" to an "A+."
Water quality is assessed based on factors such as dissolved oxygen, chlorophyll levels, water clarity, temperature, salinity, oxygen saturation, and the presence of aquatic vegetation. The report highlights that excess nitrogen, which can stimulate harmful algal blooms and deplete oxygen levels critical for marine life, has been a key focus for improvement.
Reducing nitrogen pollution entering the Sound has been identified as a major contributor to the observed improvements. Save the Sound’s Unified Water Study, initiated in 2017, has been instrumental in standardizing monitoring procedures and collecting comparable data across 52 bays and harbors within the Sound.
Despite these positive developments, Save the Sound cautions that ongoing progress could be jeopardized by the impacts of climate change, including rising water temperatures and intensified stormwater runoff. The organization emphasizes the continued necessity of reducing nitrogen pollution and investing in wastewater and stormwater infrastructure to sustain these ecological gains.