Date of Award

Spring 2004

Document Type

Legacy Thesis

Degree Name

Bachelor of Science (BS)

Department

Marine Science

College

College of Science

First Advisor

Daniel C. Abel

Abstract/Description

Winyah Bay, near Georgetown, S.C., is one of the largest estuaries on the U.S. coast. Despite its size, Winyah Bay's potential as a nursery ground for sharks has not been studied. Nurseries are rich in food and offer protection from predation, making them critical areas for sharks in early developmental stages. We studied sharks in Winyah Bay during 2002 and 2003 by long-line fishing. We divided the bay into three regions: upper, middle, and lower. A total of 10 species of sharks were captured in both years, including: Carcharhinus plumbeus, Rhizoprionodon terraenovae, Carcharhinus isodon, Carcharhinus limbatus, Sphyrna tiburo, Sphyrna lewini, Carcharhinus leucas, Ginglymostoma cirratum, Carcharhinus brevipinna, and Negaprion brevostris. The four most frequently captured species, C. plumbeus, R terraenovae, C. isodon, and C. limbatus, were further examined for their utilization of Winyah Bay as a primary or secondary nursery ground. We found that fewer young sharks (based on CPUE) were present in the bay in 2003 than 2002, coinciding with increased levels of precipitation which lowered salinity. Similarly, fewer sharks were captured at sites in the low salinity upper bay during both years. Water temperatures at all sites were warmer in 2002, which may also be attributed to the affects of the drought period. In 2002, the number of young sharks captured for each of the major species comprised a larger percentage of the total catch for each species than in 2003. Juvenile sharks were the most frequently captured age class in both years, which indicated that Winyah Bay served as a secondary nursery during the late spring, summer, and through early fall months.

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