Recent investments in wastewater and infrastructure upgrades in Connecticut and New York seem to be yielding positive results, as a new report indicates ongoing improvements in the water quality of Long Island Sound.
Save the Sound has published its 2026 Long Island Sound Report Card, revealing that water quality has either improved or stayed stable in all five open-water regions of the Sound.
The Western, Central, and Eastern basins all received A grades, whereas the Eastern Narrows was graded B.
The most notable improvement was observed in the Western Narrows, which encompasses the waters surrounding New York City, earning a D grade.
This is significant because it’s the first time since Save the Sound began its grading system in 2008 that the Western Narrows has achieved a passing grade, having consistently received an F in previous years.
The Western Basin improved from an A- to an A, while the Central Basin showed enhancement from an A to an A+.
The Eastern Basin retained its A+ grade, and the Eastern Narrows held steady at a B.
Water quality is assessed based on metrics like dissolved oxygen, chlorophyll levels, water clarity, and dissolved organic carbon, along with a balanced seaweed community.
The study evaluates multiple factors, including dissolved oxygen, chlorophyll, temperature, salinity, and aquatic vegetation.
High nitrogen levels can lead to algae blooms, which in turn may cause low-oxygen conditions harmful to fish and other marine life.
According to Save the Sound, significantly reducing nitrogen entering the Sound has been crucial for the observed water quality improvements.
The Unified Water Study, initiated by Save the Sound in 2017, aims to gain a better understanding of water quality in 52 bays and harbors of the Sound.
This initiative has established standardized monitoring procedures and protocols so that data collected by various organizations can be compared effectively across the region.
While the recent data points to improving water conditions, Save the Sound cautions that climate change, rising water temperatures, and increased stormwater runoff could jeopardize these advances.
The organization emphasizes that ongoing reductions in nitrogen pollution, alongside further investments in wastewater and stormwater infrastructure, will be vital for sustaining the positive outcomes.
