October 11, 2022

Biologists from the South Carolina Department of Natural Resources (SCDNR) are celebrating the close of a successful shorebird and seabird nesting season at the newly restored Crab Banks Seabird Sanctuary. Biologists documented more than 500 nests during the season, marking the first time coastal birds have nested since its erosion disappearance on the small island of Charleston Harbor.

SCDNR biologist Janet Thibault said, “This year was a unique opportunity to study how birds react to newly available habitat after a four-year absence. Last year the birds attempted to nest on the crab bank, this The first one that got completely screwed up was in 2017.”

Shorebirds and seabirds are declining around the world, and the 2017 loss of critical nesting sites in Charleston Harbor—one of just a handful in South Carolina—inspired a pioneering solution: By the end of 2021, The island was rebuilt with dredged material. The deepening of Charleston Harbor through a partnership with the Army Corps of Engineers, a project that garnered widespread support from community members, conservation groups, and elected officials.

Expectations were high that South Carolina’s seabirds and seabirds would quickly locate and use the new habitat—and the birds did not disappoint. Biologists discovered the first nest of the 2022 season belonging to a pair of American oystercatchers on April 1. Eight pairs of oystercatchers eventually nested on the island during the season, including a four-year-old bird that was originally bred as a chick. On Cumberland Island, Georgia.

At least one of the smaller, state-endangered seabirds, colonized the island in late April. More than 100 pairs nest on the island, and their babies congregate along the waterline in late May and June.

“At least the terns are quick to find suitable habitat,” said SCDNR biologist Mary Katherine Martin. “Extremely high tides caused these birds to lose nesting sites at other sites this spring, but the Crab Bank was the perfect location for a successful season.”

In the second week of May, a strong storm put the Crab Bank to the test during nesting season. A two-day storm with 35-knot winds blew through Charleston, driving a typically five-foot-high tide seven feet above sea level for several tidal cycles. The island experienced some slope on its southern waterline, but it experienced no seawater flooding.

One of the most spectacular sights this nesting season was the return of black skimmers and gull-billed terns to the island. Skimmers fly by opening their orange and black bills and dipping the narrow lower jaw into the water to feel the fish to eat. Gull-billed terns have heavy bills, which they use to catch fiddler crabs off the beach, and give a remarkable call, almost a giggle, during flight. SCDNR biologists counted 237 skimmer nests and 179 gull-billed tern nests in May.

Hatching success was high for both species, with the parents attending to the chicks in the summer. For these species that depend on beach habitats with little or no vegetation to lay their eggs, the Crab Bank provided the ideal habitat. Black skimmers and gull-billed terns were able to nest in the interior of the island, protected from the lapping waves and flood tides that often washed up on their favorite barrier island beaches.

Staff at the SCDNR Marine Resources Division have been monitoring since the Crab Bank’s completion in November 2021, using drones to gather high-resolution imagery and the height of the island. The island covers about 35 acres between 5 and 8 feet above the waterline of high tide. A grant from the National Fish and Wildlife Foundation received by Audubon South Carolina paid for the mapping work.

SCDNR biologist Gary Sundrin said, “With our imagery, we were able to determine how much habitat was created for the birds to nest. Having accurate elevation data tells us that this area under different tidal conditions. how about.” A member of the agency’s Shellfish Research Section, Sundrin’s team regularly uses drone imagery to map oyster beds. “The amount of housing available in September 2022 is the same as it was in December 2021, so there has been little change in available housing above the high tide line.”

After Hurricane Ian, which made landfall in South Carolina as a Category 1 hurricane, crews reported that the island received no saltwater floods and remained above the storm’s tidal level, as designed.

Kayakers and sailors in and out of Shem Creek have been able to see seabirds once again resting along the water line and flying over the harbor. With grant money from the National Fish and Wildlife Foundation, which Audubon South Carolina received, Coastal Expeditions, an ecotour company, took more than 4,000 students and members of the public to view wildlife from the water on the Crab Bank.

SCDNR is deeply grateful to the suite of community and conservation organizations that helped make this project possible with fundraising support – most notably the Coastal Conservation League, Coastal Expeditions Foundation and Audubon South Carolina. The Coastal Bird Conservation Fund was created to collect funds for the restoration of the crab bank and is now being used for additional conservation projects. To learn more about the Coastal Bird Conservation Program and how you can help support coastal bird habitats in SC, visit the SCCBC website.

SCDNR-owned Crab Bank Seabird Sanctuary is completely closed from March 15 to October 15. From 16 October to 14 March, public access to the Crab Bank is permitted only in the Intertidal Zone. Dogs and camping are prohibited throughout the year.

For additional information contact:
Erin Weeks ET (843) 729-3531
WeeksE@dnr.sc.gov

Coastal Expeditions offers Crab Bank tours by kayak and boat to see and learn about this eco-gem in Charleston Harbor.