WATER QUALITY IMPROVEMENT LEVELING OFF, RISING WATER TEMPS RAISE CONCERN
Modest Signs of Improvement in NYC, Even as Many Area Bays Struggle
LARCHMONT, New York/NEW HAVEN, Connecticut — November 17, 2022 – Regional nonprofit environmental organization Save the Sound released the findings of its 2022 Long Island Sound Report Card on November 17. The biennial report has now compiled 14 years of water testing results in the open waters of Long Island Sound and four years of testing more than 50 bays and bay segments in the region. After previous years of improvement, the 2022 report raised concerns for the future, finding that trends towards improving open water quality have stalled in several portions of the Sound and poor grades in bays have persisted. Equally concerning, the report’s science advisors noted that previous gains in water quality may be threatened by rising water temperature in Long Island Sound. There were hopeful signs, as well, indicating that efforts to reduce nitrogen pollution are having a positive impact in the western Sound, demonstrated by modest improvement in open waters of New York City. The report was released with simultaneous events at Eastchester Bay on City Island in the Bronx, NY; Black Rock Harbor in Bridgeport, CT; and Northport Harbor in Northport, NY, on Long Island.
Download your copy of the 2022 LIS Report Card
Highlights from the report illustrated both “good news and bad news.” Overall, a comparative look at 14 years of data reveals that coordinated efforts in conservation and improved wastewater treatment have helped clean the Sound over more than a decade. Further, the 2022 Long Island Sound Report Card demonstrates that the waters of eastern Long Island Sound continue to register excellent grades, driven by strong tidal exchange with the Atlantic Ocean and lower population density, relative to areas further west. The Eastern Basin and Central Basin of the Sound received A+ and A grades.
However, after years of gradual improvement, particularly in the late 2010s, the Western Basin and Eastern Narrows have seemingly plateaued, stalling at B+ and C grades, respectively. Science advisors reviewing the data warned of the potential for regression. The Western Basin and Eastern Narrows represent a large area of the Sound stretching from Bridgeport on the Connecticut shoreline and Port Jefferson on the Long Island shoreline, all the way to New York City.
The Western Narrows of Long Island Sound received an F, as it has in prior reports. Despite this, there was some room for optimism. Substantial financial investment in nitrogen reduction at area sewage treatment plants appears to be having a gradual, positive effect. The score for one important indicator of water quality in the Western Narrows, dissolved organic carbon (DOC), moved from a rock bottom 0% score in 2008 to a 43% in the 2022 Long Island Sound Report Card. This is a significant and promising improvement of this indicator of water quality. The DOC grade, combined with results from other indicators, still left the Western Narrows short of a passing grade with much more work to be done. Nonetheless, the gains signal that nitrogen reduction is having an impact.
The news for bays was more sobering. Of the 53 bay segments monitored, more than half (57%) received discouraging grades of C, D, or F. Only eleven bay segments earned an A. Bays are highly susceptible to pollutants from their neighboring communities. While local efforts underway have produced some improvements, the low overall grades show the impact that pollution has on coastal waters. This is especially true where tidal exchange with the open Sound is low and pollutant loads from rivers and streams feeding into bays are high. The report reaffirmed prior evidence that the quality of nearby open water in the Sound does not always predict the quality of water in adjacent bays. Even bays located near the most pristine sections of open water can still score poorly, due to localized pollution and other factors.
David Ansel, regional director of water protection for Save the Sound, commented, “We’re finding evidence that investment in clean water infrastructure leads to measurable benefits for Long Island Sound. It’s also clear that there is much more to be done, particularly in stressed bays throughout the length of the Sound, as well as in the western Sound.”
Science Advisors for the 2022 Long Island Sound Report Card, Jamie Vaudrey, PhD, and Jason Krumholz, PhD, also noted that the impacts of climate change threaten to reverse gains made in previous years unless additional measures are undertaken. They cited a 2021 peer-reviewed study from Drs. Michael Whitney and Penny Vlahos of the University of Connecticut* noting that water temperature in the western Long Island Sound is increasing by as much as 0.8 degrees Celsius (nearly 1.4 degrees Fahrenheit) per decade. (“Reducing Hypoxia in an Urban Estuary Despite Climate Warming,” Michael M. Whitney and Penny Vlahos, Environ. Sci. Technol. 2021, 55, 2, 941–95, Jan. 5, 2021) Rising water temperature has a range of damaging impacts on the marine environment. Among its impacts, rising temperatures elevate the risk for hypoxia – low levels of oxygen in the water. As the 2022 Long Island Sound Report Card states simply, “the warmer the water, the less oxygen it is able to hold…Many longtime residents of the region remember the severe hypoxic conditions that plagued the Sound back in the 1970s and 1980s, when fish kills were commonplace between Bridgeport, CT, and New York City.”
Dr. Vaudrey, University of Connecticut, commented, “Reducing nitrogen pollution continues to be a critical issue which is only made worse with rising temperatures from climate change. Implementing additional approaches for nitrogen reduction is an urgent priority in order to continue improving water quality in the Sound.”
Dr. Krumholz added, “The good news contained in this report is that tactics designed to improve water quality in Long Island Sound have been effective. It takes reliable long-term data to identify what is working and where, and just as important, what areas need more help. While progress has been made, continued efforts are necessary to meet our ultimate goals.”
Data on water quality in the bays of Long Island Sound were compiled by 24 partner organizations working with identical water testing procedures in the Unified Water Study, funded by the federal EPA’s Long Island Sound Study and administered by Save the Sound. The organizations track levels of dissolved oxygen, chlorophyll a, water clarity, seaweeds, and oxygen saturation to determine annual scores. Open water scores are generated from sampling programs conducted by the Connecticut Department of Energy and Environmental Protection, Interstate Environmental Commission, and New York City Department of Environmental Protection, and are graded using a metric which includes dissolved oxygen, chlorophyll a, water clarity, and dissolved organic carbon.
Results from the 2022 Long Island Sound Report Card have been posted to www.SoundHealthExplorer.com. The site, operated by Save the Sound, includes an interactive map allowing visitors to click on open water basins and specific bays to view water quality grades and the data behind them. The site includes specific actions that local residents can take to protect and improve the water quality of Long Island Sound and its numerous bays.
“It’s hard to overstate Long Island Sound’s significance to both the economy and culture of our state,” said Senator Chris Murphy of Connecticut. “Today’s Report Card shows the tireless work of Save the Sound and local partners is paying off, but is also an urgent reminder that man-made climate change is the single-greatest threat to the health of our waterways. I’m proud that we secured $2.6 billion for coastal preservation projects in Connecticut as part of the Inflation Reduction Act, and I’ll continue pushing for the investments we need to ensure the health of the Sound for generations.”
“As Co-Chair of the Congressional Long Island Sound Caucus, I am proud to fight on a bipartisan basis for improvements to the Sound to monitor water quality, to protect wetlands and marine life, and reduce pollution,” said Congresswoman Rosa DeLauro (CT-3). “This year’s comprehensive study of the Sound reveals that there is much work to do in preserving climate resiliency and our protection of the Sound. I am committed to continuing to lead my colleagues in ensuring the protection and preservation of our natural resources, our climate, and our treasure — the Long Island Sound.”