The marshes, mudflats, sandbars, shellfish beds, and shallows that once characterized the Lower East River’s shorelines vanished long ago. Today, the channel is lined almost entirely with piers and relieving platforms, bulkheads, sea walls, crib walls, revetments, and rip-rap, structures that block the natural interchange of land and water or else block the light that gives life to them both.

Quietly, though, in a few tiny spots that have been overlooked or neglected, nature has been reclaiming shoreline territory. One such spot is the Cove between the Bridges at Brooklyn Bridge Park.

When the tide comes in around New York City, it floods the straits that separate Staten Island and Manhattan Island from the continental mainland and that connect to Long Island Sound, and also floods the basins of Sandy Hook, Jamaica, and Pelham Bays.

The incoming tide reaches up the Hudson River all the way to Troy, NY, carrying salt water at least as far as Peekskill, and goes up the Raritan River to New Brunswick, NJ, and up other New Jersey rivers as well. As the tide goes out, the fresh waters of the rivers join the tide from 16,300 square miles of watershed, bringing sediments and organic matter down with the water.

The ebb and flow action of the tides over this vast and varied terrain, together with the mixing of fresh and salt waters, keeps the waters continuously abundant with nutrients. This is the Hudson-Raritan Estuary.

The waters of the East River come from the nearby rivers and creeks as well as the sea. Fresh waters enter from the Bronx River, Newtown Creek and other creeks, but mostly from the Hudson River, flushed in by way of Upper New York Bay. (The East River begins flooding two hours before the Hudson completes its ebb.)

Most pollutants and toxins in the East River are brought in runoff from the hard land surfaces associated with development, released either directly through the ground or through storm drains and combined sewer outfalls. Lesser inputs are from older wastewater treatment plants, historically contaminated sediments, illegal dumping, and the fuels and exhausts of commercial and recreational marine vehicles. Industrial discharges, highly regulated now, are a trickle compared to what they once were.

Since passage of the federal Clean Water Act in 1972, concerted efforts to reduce harmful inputs and to preserve and restore habitat have allowed the estuary’s water quality to improve. Most contaminants have decreased tenfold. Water quality will always vary as heavy rains or snows increase the inflow of pollutants or as hot spells make for warmer waters that hold less oxygen. It is monitored principally by the New York City Department of Environmental Protection, the New Jersey Harbor Dischargers Group, and volunteer citizens groups.

The Cove was formed by the waters of the estuary, which scoured it out over eighty to one hundred years, impelled by the forces of weather, waves, and tidal currents, and by the wakes of passing watercraft.

The large rocks that edge the Cove, set in place in 2002-2003 by the New York City Department of Parks and Recreation and the New York State Office of Parks, Recreation and Historical Preservation, have been strategically positioned as rip-rap to prevent the waters from carrying off any more land. Along the east side of the Cove, the waters themselves are stabilizing the shoreline, by alternately depositing and removing sediments. The beaches are sandy or muddy where the tidal action is gentlest and gravelly where stronger forces carry off the smaller grains. The bits of buffed brick and polished glass tell of the years of tidal action on the old fill.

The Cove’s habitat of upland rocks, beaches, and shallow waters is often described as littoral, which simply means ”of the shoreline.” The strip of earth between the reaches of the highest high tide and lowest low tide is called the intertidal zone or the littoral zone. Constantly shifting between water and air environments, fully vulnerable to extremes of temperature, salinity, wind and storms, flood and drought, waves and wakes, it seems hardly a place where anything could live. Yet it is rich with life, and its life forms, all adapted to avoid or endure these conditions, link together the life of the surrounding land, water, and air.

        Cindy Goulder