Movements of pantropical spotted dolphins in Hawaiian waters

Genetic studies and sighting distributions were used to delineate four stocks of pantropical spotted dolphins in Hawaiian waters: a pelagic stock and insular stocks off Hawaiʻi, Maui Nui, and Oʻahu. Information on short-term movements and space use in Hawai‘i is limited, yet such information is critical to their conservation, particularly in light of recent documentation of frequent interactions between fishing vessels and spotted dolphins throughout the main Hawaiian Islands (Baird & Webster, 2020). In this project we are characterizing spotted dolphin movements derived from satellite tag data and relating them to environmental features and current designated stock boundaries, finding that current designated boundaries are not adequate for some island-associated populations. In addition, we are evaluating movement behavior (e.g., move persistence) over diel and lunar temporal cycles for potential inference on their foraging ecology.

Link to the original Pacific Science Review Group report: https://www.cascadiaresearch.org/files/publications/Baird-PSRG-2019-15-spotted_movements.pdf

References: Baird, R.W. and D.L. Webster. 2020. Using dolphins to catch tuna: assessment of associations between pantropical spotted dolphins and yellowfin tuna hook and line fisheries in Hawaii. Fisheries Research doi:10.1016/j.fishres.2020/1205652

Courbis et al. 2014. Multiple populations of pantropical spotted dolphins in Hawaiian waters. Journal of Heredity 105(5): 627-641. doi: https://doi.org/10.1093/jhered/esu046

Oleson et al. 2013. Island-associated stocks of odontocetes in the main Hawaiian Islands: a synthesis of available information to facilitate evaluation of stock structure. PIFSC Working Paper WP-13-003. Pacific Islands Fisheries Science Center.

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Michaela A. Kratofil
(she/her), Research Assistant