Posted on April 24, 2023
A dredging operation by the U.S. Army Corps of Engineers, done over the winter, to clear critical shoaling in Big Foot Slough and replenish its dredge-spoil island will benefit nesting bird habitat.
The slough, located in the Pamlico Sound off Ocracoke, is a channel used by the sound ferries that go to Swan Quarter and Cedar Island.
The contractor Cottrell Contracting Corp. used the “Lexington,” an 18-inch cutter head suction dredge, to complete the work in January. Regular ferry runs to Swan Quarter and Cedar Island resumed mid-March.
A total of 210,000 cubic yards of material was excavated and placed onto the “spoil” island known to locals as Big Foot Island, according to Jed Cayton, a public affairs specialist with the Army Corps (USACE).
“Material” means the removed sediment, which in this operation is sand.
Big Foot Island has been battered by storms in last few years eroding this major habitat for roosting and nesting birds.
The placement of the material onto the island was done in consultation with the N.C. Wildlife Resources Commission (NCWRC) to minimize disturbance to wildlife and that is the reason why this time of the winter was chosen.
The two species most likely to benefit are Royal Terns and Sandwich Terns along with Common Terns, Gull-billed Terns, Least Terns, and Black Skimmers, according to Carmen Johnson, a wildlife biologist with NCWRC.
Replenished Big Foot dredge spoil should provide an important nesting habitat for this Royal Tern (orange beak) surrounded by Sandwich Terns.
“Many colonial nesting waterbirds build their nests on bare sand and need open, sparsely vegetated areas to establish nesting colonies,” she wrote in an email. “As development of the coastline has continued there are fewer places where these birds are able to nest and raise their young and maintaining dredge spoil islands is important to ensuring these species thrive in our state.”
Johnson noted on a visit on April 14, there were no signs of nesting yet, but the previous day estimated there were 200 Royal and Sandwich Terns roosting on the island.
The replenished island is now completely covered in sand. In a few years when vegetation returns naturally, it will attract Brown Pelicans to nest.
“It is always a good thing when you have the added benefit of ‘beneficial use’ material, which is when we use dredged material as a resource instead of treating it as a waste product,” said Col. Benjamin A. Bennett, USACE district commander in Wilmington. “Beneficial uses can include habitat restoration, beach nourishment, landfill cover and land site remediation.
“This project is a perfect example of the good work done by the people at USACE as well as our partners at NC Wildlife Resources Commission.”
As far as the North Carolina Ferry System goes, the regular dredging efforts that occur in Big Foot Slough (in the Pamlico Sound) and at Sloop Channel (in Hatteras Inlet) are critical to keeping ferry channels at safe depths and maintaining regular ferry service to Ocracoke Island, said Tim Hass of the NC Ferry Division’s Communications Office.
Shoaling occurs when waves push sand into an area and decrease the water depth making it too shallow for boats to move through easily.
This graphic from the Army Corps of Engineers shows Big Foot Island before recent dredging replenished it, left, and after.
