Long Island Sound Acidifies During Droughts

New York’s Long Island Sound (LIS), a crucial North Atlantic estuary, faces significant environmental challenges due to urbanization and heavy water traffic. Passenger transport, fishing, and cargo ships contribute to noise pollution, chemical and nutrient pollution, and eutrophication. This nutrient enrichment fosters algal blooms, which deplete oxygen levels in the water as they decompose, leading to hypoxia and mass die-offs of marine life.

Recent research published in *Frontiers in Marine Science* by Lauren Barrett and colleagues from the University of Connecticut focuses on the eutrophication-induced acidification of LIS. They studied nutrient enrichment, primarily nitrogen from atmospheric deposition, wastewater discharge, and fertilizer runoff, and its impact on the marine carbonate system. Sampling between 2020 and 2022, the researchers measured dissolved organic carbon and total alkalinity, critical parameters for understanding changes in ocean chemistry.

Their findings showed that freshwater input from the Housatonic and Connecticut rivers significantly affects acidification levels. During the droughts of 2020 and 2022, increased dissolved organic carbon and total alkalinity in river discharges resulted in more acidic conditions in LIS. Conversely, in 2021, higher freshwater input from tropical storms led to reduced acidification.

This research highlights the link between hypoxia and acidification during low river flow seasons, contrasting with other estuaries where nutrient input decreases during droughts. Despite efforts to reduce nitrogen levels in LIS, further measures are needed to combat eutrophication and its resulting hypoxia and acidification. As climate change intensifies droughts, addressing acidification in LIS becomes increasingly urgent.