Title

Genetic Diversity of White Sharks, Carcharodon carcharias, in the Northwest Atlantic and Southern Africa

Authors

Shannon J. O'Leary, State University of New York - Stony Brook
Kevin A. Feldheim, Field Museum of Chicago
Andrew T. Fields, State University of New York - Stony Brook
Lisa Natanson, National Oceanic and Atmospheric Administration
Sabine Wintner, University of KwaZulu-Natal - Durban, South Africa
Nigel Hussey, University of Windsor - Canada
Mahmood S. Shivji, Nova Southeastern UniversityFollow
Demian D. Chapman, State University of New York - Stony Brook; Institute of Ocean Conservation Science

Document Type

Article

Publication Date

5-2015

Publication Title

Journal of Heredity

Keywords

Bottleneck, Effective population size Ne, Inbreeding

ISSN

0022-1503

Volume

106

Issue/No.

3

First Page

258

Last Page

265

Abstract

The white shark, Carcharodon carcharias, is both one of the largest apex predators in the world and among the most heavily protected marine fish. Population genetic diversity is in part shaped by recent demographic history and can thus provide information complementary to more traditional population assessments, which are difficult to obtain for white sharks and have at times been controversial. Here, we use the mitochondrial control region and 14 nuclear-encoded microsatellite loci to assess white shark genetic diversity in 2 regions: the Northwest Atlantic (NWA, N = 35) and southern Africa (SA, N = 131). We find that these 2 regions harbor genetically distinct white shark populations (Φ_ST = 0.10, P< 0.00001; microsatellite F _ST = 0.1057, P < 0.021). M-ratios were low and indicative of a genetic bottleneck in the NWA (M-ratio = 0.71, P < 0.004) but not SA (M-ratio = 0.85, P = 0.39). This is consistent with other evidence showing a steep population decline occurring in the mid to late 20th century in the NWA, whereas the SA population appears to have been relatively stable. Estimates of effective population size ranged from 22.6 to 66.3 (NWA) and 188 to 1998.3 (SA) and evidence of inbreeding was found (primarily in NWA). Overall, our findings indicate that white population dynamics within NWA and SA are determined more by intrinsic reproduction than immigration and there is genetic evidence of a population decline in the NWA, further justifying the strong domestic protective measures that have been taken for this species in this region. Our study also highlights how assessment of genetic diversity can complement other sources of information to better understand the status of threatened marine fish populations.

Comments

©The American Genetic Association. 2015. All rights reserved.

NSUWorks Citation

O'Leary, Shannon J.; Kevin A. Feldheim; Andrew T. Fields; Lisa Natanson; Sabine Wintner; Nigel Hussey; Mahmood S. Shivji; and Demian D. Chapman. 2015. "Genetic Diversity of White Sharks, Carcharodon carcharias, in the Northwest Atlantic and Southern Africa." Journal of Heredity 106, (3): 258-265. doi:10.1093/jhered/esv001.

ResearcherID

G-4080-2013

DOI

10.1093/jhered/esv001