In 2014, New Jersey reused 7,000 cubic yards of dredged sand at Ring Island; the new nesting ground was later used by 4 threatened or at-risk shorebird species

New Jersey's coast has been giving way to rising seas for years, and its beach-nesting birds have been losing nesting habitat right along with it. In August 2014, project partners tried an odd solution with sand dredged from a nearby waterway. According to The Waterways Journal, a dredging contractor working with the U.S. Army Corps of Engineers placed about 7,000 cubic yards of that sediment on Ring Island, a marsh island in Middle Township near Stone Harbor in Cape May County, to build a raised berm of bird habitat. The Corps' Philadelphia District describes this as a departure from the traditional practice of placing dredged material in confined disposal facilities. The goal was to turn that sand into a raised nesting platform for colonial and marsh-nesting birds that were losing habitat and having nests flooded.

A shrinking coastline, a shrinking nursery

Species like the black skimmer and the least tern once nested in large numbers along the barrier island beaches of New Jersey and on sandy patches at the edges of salt marshes. Storms, rising seas, and coastal development have eaten away at that space over the decades. Today, both birds are listed as endangered in New Jersey. The American oystercatcher and the common tern are not listed as endangered but are designated by the state as species of greatest conservation need. All four have been coming up short of safe, dry ground on which to lay their eggs, because nests placed too low get washed out by high tides and storm surges.

Transforming dredged sand into a nesting island

The Ring Island project began as a routine maintenance dredge of the New Jersey Intracoastal Waterway, the kind that regularly produces sand needing disposal. Rather than treating it as waste, project partners dumped some 7,000 cubic yards of it onto about one acre of marsh, an area nearly the size of a football field, to raise the ground above the average high tide line. A research poster by Wetlands Institute scientists led by Lisa Ferguson noted that the sand used was almost entirely sand dredged from a nearby channel shoal, built up so the site would sit above spring tides and even storm-driven flood levels, providing birds with open, mostly bare ground to nest on.

The birds started arriving

Samantha Collins, a scientist at the Wetlands Institute, presented a paper at a 2021 conference of The Wildlife Society explaining that it took a couple of years for birds to find the new island. American oystercatchers and least terns were the first to nest there, and by 2017, three years after construction, black skimmers and common terns had established colonies as well. The same research monitored Ring Island and a second nesting island later constructed at Great Flats, counting diamondback terrapins and horseshoe crabs laying eggs on the raised sand, as well as more than 50 bird species using the two sites combined.

Why this matters beyond a single island

Ring Island was a kind of proof of concept. A similar approach was applied in December 2018 to construct a second nesting island nearby, Great Flats. Both projects fed into the Seven Mile Island Innovation Lab, a 2019 partnership between the Army Corps, New Jersey state agencies, and the nonprofit Wetlands Institute that aims to study and expand this kind of dredged-sediment reuse along the coast. The work at Ring Island was supported in part by the National Fish and Wildlife Foundation's Hurricane Sandy Coastal Resiliency Program and by New Jersey state funds. The idea is based on a broader set of practices known as Engineering With Nature, which attempts to synchronize routine infrastructure work, such as dredging a channel, with ecological benefits rather than treating the two as separate problems.

The fix has not proven permanent, and the researchers have been careful not to oversell it. Over time, vegetation grows over open sand, making it less attractive to birds that like bare or sparsely covered ground, and the extra height that the sand provides settles over time. In March 2018, the Army Corps dumped another 1,200 cubic yards of sand on Ring Island to restore its height and remove plant growth, a maintenance step the project team anticipated doing every few years.

A small island, a bigger shift in thinking

What happened at Ring Island is a small example of a larger shift in how coastal engineers look at dredged material. For decades, sand dredged from shipping channels was simply dumped in confined disposal sites. The recycling to create bird nesting habitat was turning a routine maintenance cost into an ecological benefit, although that benefit requires continued maintenance to keep it going. As sea levels rise along the U.S. Atlantic coast, projects like this one provide a small but repeatable template for pairing everyday infrastructure work with habitat recovery, one dredged channel at a time.