Winter use of Winyah Bay, SC by the Spiny Dogfish (Squalus acanthias), and their movements south of Cape Hatteras, NC

• Main Author: Langford, Meredith L.
• Format: Thesis
• Language: unknown
• Published: CCU Digital Commons 2022
• Subjects: Acoustic tracking; Movements; Seasonal habitat use; Spiny Dogfish; Squalus acanthias; Animal Sciences; Aquaculture and Fisheries; Biology; spiny dogfish
• Online Access: https://digitalcommons.coastal.edu/etd/140; https://digitalcommons.coastal.edu/cgi/viewcontent.cgi?article=1192&context=etd

South of Cape Hatteras, NC, little is known about the coastal distribution and movement of the Spiny Dogfish, Squalus acanthias. Between January 2018 and March 2020 this study conducted winter demersal longline sampling in Winyah Bay, SC to investigate habitat use by Spiny Dogfish. In addition to monitoring Winyah Bay use through catch-and-release, 13 individuals were outfitted with implanted Vemco™ acoustic transmitters to monitor large scale movements along the U.S. East Coast. Across three sampling seasons 84 female Spiny Dogfish were captured within lower Winyah Bay. No males were observed over the course of the study. The mean fork length of captured females was 79.6 cm (SD = 4.6 cm). Over 90% of captured females had fork lengths consistent with length-at-maturity data (FL = 72.5 cm) published by the American Fisheries Society (Campana et al. 2009). Spiny Dogfish were observed only for a short temporal window inside Winyah Bay. Raw abundance (n = 81) and CPUE (2.02 ± 4.12; mean ± SD) were highest in the month of February with most individuals being caught in the first half of the month. The average capture temperature was 12°C ± 1.1. Acoustic monitoring revealed northern movement from Winyah Bay, with all tagged sharks spending time in sheltered waters near Beaufort, NC in the months of March and April. Three tagged individuals were detected as far north as New Jersey, New York and Massachusetts. One tagged individual was detected again in Winyah Bay, logging detections in the bay nearly a year after its initial tagging. The brief but recurring nature of Spiny Dogfish in Winyah Bay suggest that coastal, and estuarine, waters off South Carolina function as overwintering grounds for mature females south of Cape Hatteras, NC.