title: Genetic Diversity of White Sharks, Carcharodon carcharias, in the Northwest Atlantic and Southern Africa.
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.
authors.affiliation: From the School of Marine and Atmospheric Science, Stony Brook University, Stony Brook, NY 11394 (O'Leary, Fields, and Chapman); the Pritzker Laboratory for Molecular Systematics and Evolution, The Field Museum, Chicago, IL 60605 (Feldheim); the National Marine Fisheries Service, Apex Predators Program, Narragansett, RI 02882 (Natanson); the KwaZulu-Natal Sharks Board and Biomedical Resource Unit, University of KwaZulu-Natal, Durban 4000, South Africa (Wintner); the Great Lakes Institute for Environmental Research University of Windsor, Windsor, Ontario N9B3P4, Canada (Hussey); the Save our Seas Shark Center and Guy Harvey Research Institute, Nova Southeastern University, FL 33004 (Shivji); and the Institute of Ocean Conservation Science, Stony Brook, NY 11794 (Chapman). shannon.O'Leary@tamucc.edu.
authors.forename: Shannon J
authors.initials: SJ
authors.lastname: O'Leary
authors.affiliation: From the School of Marine and Atmospheric Science, Stony Brook University, Stony Brook, NY 11394 (O'Leary, Fields, and Chapman); the Pritzker Laboratory for Molecular Systematics and Evolution, The Field Museum, Chicago, IL 60605 (Feldheim); the National Marine Fisheries Service, Apex Predators Program, Narragansett, RI 02882 (Natanson); the KwaZulu-Natal Sharks Board and Biomedical Resource Unit, University of KwaZulu-Natal, Durban 4000, South Africa (Wintner); the Great Lakes Institute for Environmental Research University of Windsor, Windsor, Ontario N9B3P4, Canada (Hussey); the Save our Seas Shark Center and Guy Harvey Research Institute, Nova Southeastern University, FL 33004 (Shivji); and the Institute of Ocean Conservation Science, Stony Brook, NY 11794 (Chapman).
authors.forename: Kevin A
authors.initials: KA
authors.lastname: Feldheim
authors.affiliation: From the School of Marine and Atmospheric Science, Stony Brook University, Stony Brook, NY 11394 (O'Leary, Fields, and Chapman); the Pritzker Laboratory for Molecular Systematics and Evolution, The Field Museum, Chicago, IL 60605 (Feldheim); the National Marine Fisheries Service, Apex Predators Program, Narragansett, RI 02882 (Natanson); the KwaZulu-Natal Sharks Board and Biomedical Resource Unit, University of KwaZulu-Natal, Durban 4000, South Africa (Wintner); the Great Lakes Institute for Environmental Research University of Windsor, Windsor, Ontario N9B3P4, Canada (Hussey); the Save our Seas Shark Center and Guy Harvey Research Institute, Nova Southeastern University, FL 33004 (Shivji); and the Institute of Ocean Conservation Science, Stony Brook, NY 11794 (Chapman).
authors.forename: Andrew T
authors.initials: AT
authors.lastname: Fields
authors.affiliation: From the School of Marine and Atmospheric Science, Stony Brook University, Stony Brook, NY 11394 (O'Leary, Fields, and Chapman); the Pritzker Laboratory for Molecular Systematics and Evolution, The Field Museum, Chicago, IL 60605 (Feldheim); the National Marine Fisheries Service, Apex Predators Program, Narragansett, RI 02882 (Natanson); the KwaZulu-Natal Sharks Board and Biomedical Resource Unit, University of KwaZulu-Natal, Durban 4000, South Africa (Wintner); the Great Lakes Institute for Environmental Research University of Windsor, Windsor, Ontario N9B3P4, Canada (Hussey); the Save our Seas Shark Center and Guy Harvey Research Institute, Nova Southeastern University, FL 33004 (Shivji); and the Institute of Ocean Conservation Science, Stony Brook, NY 11794 (Chapman).
authors.forename: Lisa J
authors.initials: LJ
authors.lastname: Natanson
authors.affiliation: From the School of Marine and Atmospheric Science, Stony Brook University, Stony Brook, NY 11394 (O'Leary, Fields, and Chapman); the Pritzker Laboratory for Molecular Systematics and Evolution, The Field Museum, Chicago, IL 60605 (Feldheim); the National Marine Fisheries Service, Apex Predators Program, Narragansett, RI 02882 (Natanson); the KwaZulu-Natal Sharks Board and Biomedical Resource Unit, University of KwaZulu-Natal, Durban 4000, South Africa (Wintner); the Great Lakes Institute for Environmental Research University of Windsor, Windsor, Ontario N9B3P4, Canada (Hussey); the Save our Seas Shark Center and Guy Harvey Research Institute, Nova Southeastern University, FL 33004 (Shivji); and the Institute of Ocean Conservation Science, Stony Brook, NY 11794 (Chapman).
authors.forename: Sabine
authors.initials: S
authors.lastname: Wintner
authors.affiliation: From the School of Marine and Atmospheric Science, Stony Brook University, Stony Brook, NY 11394 (O'Leary, Fields, and Chapman); the Pritzker Laboratory for Molecular Systematics and Evolution, The Field Museum, Chicago, IL 60605 (Feldheim); the National Marine Fisheries Service, Apex Predators Program, Narragansett, RI 02882 (Natanson); the KwaZulu-Natal Sharks Board and Biomedical Resource Unit, University of KwaZulu-Natal, Durban 4000, South Africa (Wintner); the Great Lakes Institute for Environmental Research University of Windsor, Windsor, Ontario N9B3P4, Canada (Hussey); the Save our Seas Shark Center and Guy Harvey Research Institute, Nova Southeastern University, FL 33004 (Shivji); and the Institute of Ocean Conservation Science, Stony Brook, NY 11794 (Chapman).
authors.forename: Nigel
authors.initials: N
authors.lastname: Hussey
authors.affiliation: From the School of Marine and Atmospheric Science, Stony Brook University, Stony Brook, NY 11394 (O'Leary, Fields, and Chapman); the Pritzker Laboratory for Molecular Systematics and Evolution, The Field Museum, Chicago, IL 60605 (Feldheim); the National Marine Fisheries Service, Apex Predators Program, Narragansett, RI 02882 (Natanson); the KwaZulu-Natal Sharks Board and Biomedical Resource Unit, University of KwaZulu-Natal, Durban 4000, South Africa (Wintner); the Great Lakes Institute for Environmental Research University of Windsor, Windsor, Ontario N9B3P4, Canada (Hussey); the Save our Seas Shark Center and Guy Harvey Research Institute, Nova Southeastern University, FL 33004 (Shivji); and the Institute of Ocean Conservation Science, Stony Brook, NY 11794 (Chapman).
authors.forename: Mahmood S
authors.initials: MS
authors.lastname: Shivji
authors.affiliation: From the School of Marine and Atmospheric Science, Stony Brook University, Stony Brook, NY 11394 (O'Leary, Fields, and Chapman); the Pritzker Laboratory for Molecular Systematics and Evolution, The Field Museum, Chicago, IL 60605 (Feldheim); the National Marine Fisheries Service, Apex Predators Program, Narragansett, RI 02882 (Natanson); the KwaZulu-Natal Sharks Board and Biomedical Resource Unit, University of KwaZulu-Natal, Durban 4000, South Africa (Wintner); the Great Lakes Institute for Environmental Research University of Windsor, Windsor, Ontario N9B3P4, Canada (Hussey); the Save our Seas Shark Center and Guy Harvey Research Institute, Nova Southeastern University, FL 33004 (Shivji); and the Institute of Ocean Conservation Science, Stony Brook, NY 11794 (Chapman).
authors.forename: Demian D
authors.initials: DD
authors.lastname: Chapman
mesh_terms: D000353:Africa, Southern; D000818:Animals; D001267:Atlantic Ocean; D004272:DNA, Mitochondrial / Q000235:genetics; D005260:Female; D014644:Genetic Variation; D005828:Genetics, Population; D006239:Haplotypes; D007178:Inbreeding; D008297:Male; D018895:Microsatellite Repeats; D011157:Population Dynamics; D017422:Sequence Analysis, DNA; D012754:Sharks / Q000235:genetics*
chemical_list: D004272:DNA, Mitochondrial
keywords: bottleneck; effective population size Ne; inbreeding