Fifty years ago, Congress voted to override President Richard Nixon’s veto of the Clean Water Act. It has proved to be one of the most transformative environmental laws ever enacted.
At the time of the law’s passage, hundreds of millions of gallons of raw sewage was dumped by New York City into the Hudson River every day. This filth was compounded by industrial contaminants emptied into the river along much of its length. The catch basin for all of this was New York Harbor, which resembled an open sewer. At its worst, 10 feet of raw human waste blanketed portions of the harbor bottom, and certain reaches held little or no oxygen to sustain the life of its fishery. Trash floated among oil slicks.
Health advisories against eating fish from the Hudson remain, but its ecology has largely recovered, thanks to the law, which imposed strict regulations on what could be discharged into the water by sewage treatment plants, factories and other sources of pollution. Today people swim in organized events in New York Harbor, which would have been unthinkable in 1972 when the law was passed. Across the country, billions of dollars were also spent to construct and improve sewage treatment plants, leading to recoveries of other urban waterways.
Cleaner water has made the harbor far more hospitable, and other steps have helped to rebuild life there, like fishing restrictions and the removal of some dams on tributaries in the Hudson River watershed.
The harbor’s environment remains compromised even so. It continues to be stressed by sewage overflow during rainstorms and by habitat degradation, such as loss of salt marshes from development and sea level rise. But the ecological workings of the harbor have been returned to a functional level, a revitalization that owes much to this landmark act of Congress.
Fifty years on, the story of this remarkable recovery can be told through some of its key animal species.
American oyster Oyster reefs once covered roughly 350 square miles of harbor bottom around New York City. Untreated sewage contributed to a severe decline in the oyster population that lasted through the 20th century. The wild oyster population has begun to recover; a nine-incher known as Big was found in 2018 by a diver at a Hudson River pier. The nonprofit Billion Oyster Project is also at work restoring oyster reefs in the harbor, which provide habitat for other species.
Alewife This small, freshwater-marine herring species is an important prey fish. Its numbers have been reduced by some 1,600 dams in the Hudson watershed, many of which block access to their spawning habitat. But some dams are now being removed, which should help its population rebound.
Bald eagle Once a rarity across North America, largely because the now-banned pesticide DDT compromised its ability to reproduce by weakening its eggshells, the bald eagle has made a strong comeback, taking advantage of the harbor’s resurgent fish life. As many as 10 now live on Staten Island, including the borough’s first nesting pair, known as Vito and Linda.
Humpback whale Theincreased abundance of menhaden, a critical food source for the whales, has likely drawn humpbacks into the Hudson estuary. In December 2020 a humpback whale was seen in the Hudson just one mile from Times Square.
Harbor heron Herons, egrets and ibis once nested all over New York Harbor. But demand for their plumage for women’s hats in the late 19th century, followed by the decimation by sewage pollution of the fish and crabs they preyed on, contributed to almost a century-long absence. Improved water quality has led to the birds’ recovery, with more than a thousand breeding pairs.
Atlantic sturgeon Sturgeon are ancient fish, originating some 200 million years ago. They hatch in the river, then spend time in the ocean before returning to their birthplace to spawn. In the late 1900s the Hudson’s population was plundered for its valuable caviar, but protections have led to some recovery. Researchers using sonar documented a 14-footer in the central Hudson in 2018.
Marine borers Cleaner waters have helped these invertebrates flourish. Which has been bad news for any wood in the water, especially piers and pilings. One of the most common of these borers is the wormlike clam Teredo navalis, which uses a hinged shell at its head to drill holes in wood pilings and ship hulls and then burrow within. Another is a tiny crustacean known as a gribble, which likes to gnaw at wood from the outside. Preventing this destruction can be very expensive. Brooklyn Bridge Park has spent more than $100 million applying epoxy to pilings under piers at the park to guard against them.
Osprey Like the bald eagle, osprey numbers plummeted because of the widespread use of DDT. Today this bird of prey, also known as a fish hawk, is often spotted over the harbor hunting fish close to the surface, which they snatch with their outstretched talons. The cleaner harbor’s revitalized fish populations have helped drive the osprey’s return.
John Waldman is a professor of biology at Queens College and the author of “Heartbeats in the Muck: The History, Sea Life, and Environment of New York Harbor.”
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