Population abundance and habitat utilization of bottlenose dolphins in the Mississippi Sound

Abstract

Distance sampling principles were utilized to examine population density and abundance for bottlenose dolphins (Tursiops truncatus) in the Mississippi Sound. Information was collected during summer and winter to allow for examination of habitat utilization and abundance during two different seasons. Within the study area of the Mississippi Sound there are approximately 2225 bottlenose dolphins. The population was larger during the summer than during the winter months. Dolphins utilized coastal areas more during the summer, potentially as nursery grounds, as evidenced by larger numbers of calves and percentage of groups containing calves during this time. Bottlenose dolphin densities were lower in this area during the winter suggesting migration to deeper waters potentially in search of prey. As the Mississippi Sound is regularly utilized for a variety of human activities, the monitoring of dolphin populations in this area is critical to determine increasing or decreasing trends in population abundance due to potential anthropogenic factors that may affect animal populations. Similar studies around the world could provide evidence for areas that could be protected to ensure survival of species such as dolphins and other marine mammals. Copyright © 2012 John Wiley & Sons, Ltd.