Seasonal Presence of Atlantic Sturgeon and Sharks at Cape Hatteras, a Large Continental Shelf Constriction to Coastal Migration

Abstract

Cape Hatteras is a major topographic feature on the continental shelf of the U.S. eastern seaboard that changes the dynamics of nearshore large ocean currents, including the Labrador Current and Gulf Stream. Cape Hatteras constricts shelf habitat and restricts the migratory corridors of highly migratory species through this area. Our objective was to describe the seasonal patterns of presence for three species-the Spiny Dogfish Squalus acanthias, Atlantic Sturgeon Acipenser oxyrinchus oxyrinchus, and Sandbar Shark Carcharhinus plumbeus-and analyze environmental conditions associated with fish presence near this feature. These species are managed under the Magnuson-Stevens Act, and two of them are also listed as species of concern under the Endangered Species Act. Transmitter detections from tagged fish recorded by the Cape Hatteras acoustic array, which was deployed just south of the cape, indicated that these species are present year-round. The greatest number of detections occurred from November through April. This simple baseline of seasonal presence can provide insights for regional offshore development activities, which have the potential to affect movement patterns of migratory species through the Cape Hatteras constriction. Our results show the value of strategically placed acoustic arrays for observing fish habitat use and provide presence/absence data to enhance our understanding of species ecology and distribution.

Networked Animal Telemetry in the Northwest Atlantic and Caribbean Waters

“…A long-term acoustic telemetry study that focused on Gray's Reef National Marine Sanctuary detected 11 elasmobranch species, 6 teleost species, and 1 sea turtle species originating from areas both north and south of the array (Williams et al 2019). The acoustic array deployed off Cape Hatteras, North Carolina, by Rulifson et al (2020) was situated in an important migratory corridor between temperate and boreal waters to the north and subtropical waters to the south, and the array detected Atlantic Sturgeon that were originally tagged in locations ranging from Connecticut to Georgia. Dusky Sharks tagged by Bangley et al (2020) were detected from the New York Bight to Cape Lookout, North Carolina.…”

“…Telemetry networks can be effective in determining how much time a species spends within and outside of MPA boundaries, as demonstrated by Novak et al (2020, this themed issue) in their study of Yellowtail Snapper Ocyurus chrysurus movements in an MPA in the U.S. Virgin Islands. Acoustic receivers deployed along important migratory corridors can also be used to identify the timing and extent of coastal and anadromous migrations off Cape Hatteras, North Carolina (Rulifson et al 2020, this themed issue), and in the Charles River, Massachusetts (Gahagan and Bailey 2020, this themed issue).…”