Site Fidelity of Bottlenose Dolphins (Tursiops truncatus) Using Elemental Analyses and Photo-Identification
Date of Award
Ruth, Carmichael, Ph.D.
The objective of this study was to determine if bottlenose dolphins (Tursiops truncatus) in Alabama waters acquire location-specific elemental signatures indicative of site fidelity. I measured trace metal concentrations (Chapter II) and stable isotope ratios (Chapter III) in skin from free-ranging dolphins remotely biopsied in Mobile Bay, the northern Gulf of Mexico (Gulf) and eastern Mississippi Sound (EMSS). Elemental findings were corroborated with photo-identification data. I found that dolphins acquired some location-specific elements indicative of site fidelity, with the greatest differences at geographic extremes, particularly relative to salinity. For trace metals, highest concentrations were found in winter, consistent with higher riverine discharge, while stable isotope ratios did not differ between seasons. Photo-identification data supported fidelity patterns indicated by elements, showing higher connectivity within Mobile Bay than between Mobile Bay and the Gulf or EMSS. I found little or no evidence of site fidelity by dolphin groups, likely due to limited data. This multi-disciplinary study established baseline data for the understudied dolphin population in Alabama waters.
Clance, Lauren R., "Site Fidelity of Bottlenose Dolphins (Tursiops truncatus) Using Elemental Analyses and Photo-Identification" (2022). Theses and Dissertations. 49.
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