GIS Investigation of the relationship of sex and season on the population distribution of common bottlenose dolphins (Tursiops truncatus) in Charleston,South Carolina |
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| Authors: | Hannah Bouchillon Norman S Levine Patricia A Fair |
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| Institution: | 1. Graduate Program in Marine Biology, College of Charleston , Charleston, SC, USA bouchillonh@g.cofc.edu https://orcid.org/0000-0003-4598-9337;3. Department of Geology and Environmental Geosciences, College of Charleston , Charleston, SC, USA;4. Department of Public Health Sciences, Medical University of South Carolina , Charleston, SC, USA;5. NOAA's Ocean Service, National Centers for Coastal Ocean Science , Charleston, SC, 29412, USA |
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| Abstract: | ABSTRACT The Charleston Estuarine System Stock (CESS) of common bottlenose dolphins (Tursiops truncatus) has been the focus of population monitoring for the past 20 years. Photo-id studies have determined abundance and survival estimates for this population, which exhibits high site fidelity in this area. However, fine-scale distribution, utilization patterns, and the driving forces behind these patterns are lacking. Using historical photo-id data and a novel application of geographic information system (GIS) analysis, the present study identified core use areas within Charleston Harbor, as well as patterns specific to sexes and seasons. Photo-id data of 319 dolphins sighted 11 times or more during 2004–2009 were analyzed. Heat maps were developed to examine spatial distributions using kernel density estimates (KDE) and were compared between sexes and seasons. Multiple high-density core use areas were identified for this population, with the most noteworthy near the mouth of the harbor toward the Atlantic Ocean. Fine-scale distribution varied across sexes, as well as seasons. Some areas were identified as more specifically inhabited by one sex, while other areas overlapped between sexes. Females were more tightly concentrated within their distribution while males were more dispersed. Although population distribution varied across seasons, sex distributions remained. |
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| Keywords: | GIS kernel density distribution photo-identification Tursiops truncatus |
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https://orcid.org/0000-0003-4598-9337;3. Department of Geology and Environmental Geosciences, College of Charleston , Charleston, SC, USA;4. Department of Public Health Sciences, Medical University of South Carolina , Charleston, SC, USA;5. NOAA's Ocean Service, National Centers for Coastal Ocean Science , Charleston, SC, 29412, USA