Improving oyster habitat, Port Jersey, New Jersey

About 90% of all trade travels by ship. Each generation of ships has increased in size and efficiency. At the beginning of the 21st century, Port Jersey channel was not deep enough to accommodate the latest large container vessels. In 2008, the US Army Corps of Engineers and the New Jersey Department of Transportation began to deepen and widen the Port Jersey Channel to a depth of 52 ft.

Before Port Jersey was built, the Jersey flats were once home to the largest oyster reef in the original colonies. For nearly 200 years, the expansion of piers, channels, and shipping has challenged the habitat. In 1939, a channel was cut on the south side of the Military Ocean Terminal at Bayonne. After the channel was abandoned, it filled with several feet of black silt and became anoxic. The anoxic conditions made living difficult for oysters and other fish.

In the first year of the deepening project, the dredged sand was transported to a reef offshore in the Atlantic Ocean. In the second year, the project was modified, and dredged sand was used to bury the black silt and fill the anoxic channel to form a stiff, oxygenated bottom. Improving the bottom conditions helped restore the oyster habitat.

As part of the overall harbor deepening project, e4sciences measured bathymetry before and after deepening and deployed side-scan sonar and sub-bottom reflection seismology to determine sediment type and thickness. Through application of these measurements, e4sciences monitored the burial of the black silt and the filling of the channel.