Date of Award

Spring 2006

Document Type

Legacy Thesis

Degree Name

Master of Science in Coastal Marine and Wetland Studies

Department

Coastal and Marine Systems Science

College

College of Science

First Advisor

Robert F. Young

Second Advisor

Mary Crowe

Third Advisor

Craig Gilman

Abstract

The purpose of this study was to determine if the distributions of either or both Dasyatis sabina and Dasyatis americana, in Winyah Bay, S. C., vary according to salinity profiles. In 2004, stingrays were captured from May through October and in 2005 stingrays were captured from May through August using longlines with 16/0 hooks for larger stingrays and 12/0 hooks for smaller stingrays. Lines were set at both high and low tide in 2004 but only at low tide in 2005 (due to poor high-tide catch success during the first season). Soak times were 60 min for 16/0 lines and 30 min for 12/0 lines. D. sabina exhibited higher CPUE than D. americana for both sampling seasons. D. americana were captured in deeper waters and higher bottom salinities than D. sabina. A chi-square analysis revealed that the CPUE distribution across four salinity categories (0-10, 10-20, 20-30, and >30 psu) was nonrandom for both species (D. americana p = .004 and D. sabina p = .016). Specific site preferences were indicated for both species, but within these sites, CPUE was influenced by changes in salinity as seen in distributional patterns of both stingrays with the movements of tides.

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