ALBANY, N.Y.— Scientists have identified causes of large fish kills in Long Island’s Peconic River last summer, where
roughly 300,000 adult Atlantic Menhaden died.
The study by state and Suffolk County officials and Stony Brook and Cornell universities says rising water temperatures and a spike in algae blooms, spurred by increased nitrogen levels, depleted oxygen and caused many fish to suffocate.
Additional factors include predatory blue fish blocking the river’s mouth and a virus.
The fish kills occurred at three locations along the two-mile tidal portion of the river in May and June.
The Peconic River originates in bogs and wetlands in central Long Island and empties into Flanders Bay at Riverhead.
State and local agencies are working to identify and reduce nitrogen from wastewater reaching the river.