Genetic diversity of bottlenose dolphin (Tursiops sp.) populations in the western North Pacific and the conservation implications

Abstract

The evolutionary processes that shape patterns of diversity in highly mobile marine species are poorly understood, but important towards transferable inference on their effective conservation. In this study, bottlenose dolphins (Tursiops sp.) are studied to address this broader question. They exhibit remarkable geographical variation for morphology, life history, and genetic diversity, and this high level of variation has made the taxonomy of the genus controversial. A significant population structure has been reported for the most widely distributed species, the common bottlenose dolphin (T. truncatus), in almost all ocean basins, though no data have been available for the western North Pacific Ocean (WNP). The genetic diversity of bottlenose dolphins in the WNP was investigated based on 20 microsatellite and one mitochondrial DNA markers for samples collected from Taiwanese, Japanese, and Philippine waters (9°–39°N, 120°–140°E) during 1986–2012. The results indicated that there are at least four genetically differentiated populations of common bottlenose dolphins in the western and central North Pacific Ocean. The pattern of differentiation appears to correspond to habitat types, resembling results seen in other populations of the same species. Our analyses also showed that there was no evident gene flow between the two “sister species”, the common bottlenose dolphins, and the Indo-Pacific bottlenose dolphins (T. aduncus) occurring sympatrically in our study region.Electronic supplementary materialThe online version of this article (doi:10.1007/s00227-017-3232-8) contains supplementary material, which is available to authorized users.

Using Cost-Effective Surveys From Platforms of Opportunity to Assess Cetacean Occurrence Patterns for Marine Park Management in the Heart of the Coral Triangle

“…In Wakatobi bottlenose dolphins occur wide-spread in the area on a regular basis, thus residency for at least some of these animals is likely. World-wide bottlenose dolphin populations can be genetically distinct at small spatial scales, which is highly relevant for any conservation efforts (Chen et al, 2017). The use of photographs of the dorsal fin of individual animals, as well as sampling of tissue for genetic analysis, could provide more insight into this.…”

Hybridization in bottlenose dolphins—A case study of Tursiops aduncus × T. truncatus hybrids and successful backcross hybridization events

“…aduncus and T . truncatus , while a later study in that region using bi-parentally inherited nuclear DNA markers (20 microsatellite DNA loci) also found no evidence for admixture between the two species [ 14 ]. Off Australia, mtDNA lineages were distinct [ 12 , 15 ] and there was no evidence for admixture between T .…”

Concordance between genetic diversity and marine biogeography in a highly mobile marine mammal, the Risso's dolphin

“…Effective population sizes ( N e ) and the prevalence of long‐term gene flow, i.e., the number of migrants per generation ( N e m ), were estimated using the maximum likelihood coalescent methods implemented in MIGRATE 3.6.6 (Beerli & Felsenstein, ), following the method described in Chen et al. (). Recent gene flow was inferred through the presence of any first generation migrant using the frequencies‐based method (Paetkau, Slade, Burden, & Estoup, ) implemented in GeneClass2 (Piry et al., ).…”