Assessment of the Genetic Diversity of Stranded Bottlenose Dolphins (Tursiops truncatus) in the Mississippi Sound
IAAAM 2023
Nelmarie Landrau-Giovannetti1,2*+; Mark A. Arcik II3; Chuan-yu Hsu3; Corrinne E. Crover4; Stephen Reichley1,2; Zenaida Magbanua3; Olga Pechanova3; Debra Moore1,2; Anna Linhoss5; Theresa Madrigal6; Mark Peterman1,7; Ozan Ozdemir1,7; Daniel G. Peterson2; Mark Lawrence1,7; Attila Karsi1,7
1Global Center for Aquatic Health and Food Security, College of Veterinary Medicine, Mississippi State University, Mississippi State, MS, USA; 2Department of Pathobiology and Population Medicine, College of Veterinary Medicine, Mississippi State University, Mississippi State, MS, USA; 3Institute for Genomics, Biocomputing and Biotechnology, Mississippi State University, Mississippi State, MS, USA; 4Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, IA, USA; 5Department of Biosystems Engineering, College of Engineering, Auburn University, Auburn, AL, USA; 6Institute for Marine Mammal Studies, Gulfport, MS, USA; 7Department of Comparative Biomedical Sciences, College of Veterinary Medicine, Mississippi State University, Mississippi State, MS, USA
Abstract
The Mississippi Sound and adjacent waters harbor the largest bay, sound, and estuary population of bottlenose dolphins (Tursiops truncatus) in the United States.1 As top predators, dolphins serve as a good indicator of overall ecological health. However, the health of dolphins in the Mississippi Sound is influenced by natural and artificial factors, including freshwater incursions, the Deepwater Horizon oil spill, and hurricanes. Therefore, understanding the genetic variation of these bottlenose dolphins stranded on the Mississippi coast is important to understand and identify groups of genetically distinct individuals for management and conservation purposes.
In this study, we investigated the genetic variability of 400 bottlenose dolphins stranded on the Mississippi coast from 2010–2021 based on the sequences of their mitochondrial DNA (mtDNA). For each dolphin, four overlapping amplicons covering the whole mitochondrial genome were amplified using marine dolphin-specific PCR primers and sequenced using the Oxford Nanopore GridION. These sequences were mapped to the bottlenose dolphin reference mitochondrial genome and used with other complete mtDNA sequences obtained from NCBI for evolutionary and population analyses as well as single nucleotide polymorphism (SNP) identification.
The results identified 537 unique SNPs among the stranded dolphins, which clustered into five distinct subpopulations along the northwest coastline. The Mississippi Sound dolphins seem closely related to but distinct from the western North Atlantic dolphins. We expect this study will aid in our understanding of the population structure of this species in the Mississippi Sound and will be critical to the ongoing management efforts by the National Marine Fisheries Service.
Acknowledgments
The authors thank the Institute for Marine Mammal Studies personnel for sample collation and management. Funding for this project was generously provided by the Mississippi Department of Marine Resources (Gulf of Mexico Energy Security Act project number 3000027046).
*Presenting author
+Student presenter
Literature Cited
1. Mullin KD, McDonald T, Wells RS, Balmer BC, Speakman T, Sinclair C, Zolman ES, Hornsby F, McBride SM, Wilkinson KA, et al. Density, abundance, survival, and ranging patterns of common bottlenose dolphins (Tursiops truncatus) in Mississippi Sound following the Deepwater Horizon oil spill. PLoS One. 2017;12:e0186265.