Local conditions, stormwater and wastewater infrastructure, development patterns and land use play a critical part in shaping the Sound's ecological health. Water quality in the Eastern Narrows is in part a reflection of conditions in adjacent communities, including those in Westchester County. Regular scientific monitoring can be a tool to empower communities to make decisions that better protect water quality in Long Island Sound.

In 2020, the Eastern Narrows sub-region of Long Island Sound received a score of 74%, or a grade of C on a scale from A-F. This was down slightly from 2018 (82% or B-) but similar to 2016 (70% or C-). The lower grade was mainly due to worsening chlorophyll a, a measure of microalgae growth in the Sound, along with fluctuating weather conditions, according to the report card. Save the Sound also assigns a rating of Improving, Stable, Variable or Declining to each sub-region based on its scores over a 12-year period; the Eastern Narrows trend in 2020 was lowered from Stable to Variable.

Sub-region scores in 2020 were poorest on the western end of the Sound (the Western Narrows, at 44% or F) and highest on the eastern end (the Eastern Basin, at 99% or A+). That pattern has been consistent in recent years. This mainly is due to lower tidal exchange and higher population density on the western end of the Sound, according to the report card. Overall, investments in conservation and wastewater treatment have improved water quality in the Sound over the past decade, per the report card, which also recommends reducing nitrogen pollution and stormwater runoff in the future.

Save the Sound releases its reports on the ecological health of Long Island Sound every two years. The next release is expected in 2022. To learn more about scoring methodology, visit http://www.soundhealthexplorer.org/fishable/.