Meeting Abstract
18.3 Saturday, Jan. 4 10:45 Habitat Partitioning and Intrapopulation Variation in Migration Patterns of Sympatric Apex-Predatory Sharks Across a Dynamic Marine Landscape HAMMERSCHLAG, N*; GRAHAM, F/J; NELSON, E/R; HARTOG, K; HAMMERSCHLAG-PEYER, C/M; University of Miami, RJ Dunlap Marine Conservation Program; University of Miami, RJ Dunlap Marine Conservation Program; University of Miami, RJ Dunlap Marine Conservation Program; University of Miami, RJ Dunlap Marine Conservation Program; University of Miami, RJ Dunlap Marine Conservation Program nhammerschlag@rsmas.miami.edu
Ecological and evolutionary processes are inherently linked to movement. Although previous work has expanded our understanding of animal movement ecology, further studies are needed for apex predators given that changes in their movement patterns can impact ecosystem structure and function. Previous studies that have investigated foraging and movement patterns of highly migratory apex predators have generally not considered intrapopulation variation in resource use, despite the recent realization that within-population differences can impacts population dynamics. Apex predatory sharks are among the most threatened vertebrates on the planet and understanding the broad-scale movement patterns as well as areas of their core use and re-use is important for implementation of effective place-based management strategies. However, studying the movement patterns of sharks is difficult given the inherent challenges of working in the marine environment coupled with the highly migratory behavior of these animals. To address these knowledge gaps, we conducted a joint satellite tagging study to investigate the movements of three apex predatory sharks in the subtropical Atlantic (tiger Galeocerdo cuvier, great hammerhead Sphyrna mokarran, and bull shark Carcharhinus leucas). Although home ranges overlapped among all three species, we found both inter-specific habitat partitioning as well as intrapopulation variation in migration patterns. These results are discussed in terms of foraging ecology with implications for their conservation.
