Post-Hurricane Florence Sea Turtle Nesting Habitat Nest Site Selection at Cape Hatteras and Cape Lookout National Seashores

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WARC researchers will be surveying nesting beaches in Cape Hatteras and Cape Lookout National Seashores. They will record GPS locations for all crawls, nests, and turtles encountered/captured, and will be placing satellite tags on a subset of individuals to determine habitat use and delineate inter-nesting areas used by reproductive females.

The Science Issue and Relevance: The National Park Service (NPS) is mandated to protect and manage all threatened and endangered marine turtle species under the US Endangered Species Act of 1973. Cape Hatteras and Cape Lookout National Seashores (CAHA and CALO) in North Carolina have threatened loggerhead turtles (Caretta caretta) and green turtles (Chelonia mydas) regularly nesting at both CAHA and CALO and turtles may forage in local areas, but foraging locations are currently unknown. Managers at CAHA and CALO have implemented an intense, long-term (over 30 years) nesting beach project to gather valuable information on frequency and reproductive success of nesting adult female sea turtles. This area also experiences frequent hurricanes and tropical storms. To examine sea turtle nesting habitat selection post Hurricane Florence, a powerful Category 1 storm that hit the area in 2018 (September 12-15), we will implement a marine turtle tagging, sampling, and satellite-tracking study to quantify the habitat use and movement patterns of adult loggerhead and green turtles at the CAHA/CALO Seashores. Satellite tacking data will show movements of adult females of both species in the nearshore environment and across CAHA and CALO boundaries. Complementary genetic data on individual females will contribute key data towards an already on-going related genetic mark-recapture study on the Northern Recovery Unit loggerheads.

aerial image of beach

Aerial image of North Carolina beach (credit: National Park Service)

 

Science needs include where high-use zones are for sea turtles nesting in the Parks, especially after the major disturbance from Hurricane Florence, post-nesting destinations of females using the Park for nesting, and genetic makeup of individual nesting turtles to link to the ongoing genetic mark-recapture project for loggerheads and green turtles that seeks to better estimate the number of individual turtles contributing to the overall nesting numbers in the population.

 

Methodology for Addressing the Issue: We will survey nesting beaches in CAHA and CALO during peak sea turtle nesting season (determined from previous NPS daytime beach surveys). We will record GPS location for all crawls, nests, and turtles encountered/captured. When a sea turtle crawl is located and after the females have either nested or false crawled and are heading back to sea, we will intercept them for tagging; at no time will we disturb nesting turtles. We will place a pre-constructed corral around each turtle and proceed to conduct a standard workup. Note all methods and activities will mirror that of our currently approved nesting research in Dry Tortugas (DRTO) and Everglades (EVER) National Parks.

We will place satellite tags on a subset of individuals encountered on the beaches to determine habitat use and delineate inter-nesting areas used by reproductive females.  Deployment of satellite tags at both Seashores, is one of the primary goals to meet our objectives of nest site selection patterns and site fidelity, residency times, and post-nesting destinations.

loggerhead turtle (Caretta caretta)

Loggerhead turtle (Caretta caretta) with satellite tag (credit: Kristen Hart, USGS)

  

Future Steps: In the next phase of research, we will incorporate fieldwork to include both nesting beaches and in-water activities targeting all size classes of sea turtle species found at CAHA and CALO: hawksbill (Eretmochelys imbricata), Kemp's ridley (Lepidochelys kempii), and leatherback (Dermochelys coriacea) in addition to the forementioned loggerhead and green.

 

Field work for this project will begin in June 2021 and continue for 3 years.