The NEW 2026 Long Island Sound Report Card uses water quality data to analyze the ecological health of the Sound and understand how well the water can support aquatic life. This biennial report uses an assessment methodology developed for the Report Card with a Technical Advisory Committee of scientists and water managers from agencies around the Sound. We use four water quality indicators to grade the five open water segments of the Sound and five to determine Bay Grades for 62 bay segments across 46 bays and harbors. We share these grades with media outlets across the region to inform the public and with elected officials and environmental agencies to identify where water quality challenges exist and help determine solutions to improve ecosystem health. All grades in the 2026 Long Island Sound Report Card are based on data collected during the 2025 monitoring season.

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