title: The last frontier: catch records of white sharks (Carcharodon carcharias) in the Northwest Pacific Ocean.
abstract: White sharks are highly migratory apex predators, globally distributed in temperate, sub-tropical, and tropical waters. Knowledge of white shark biology and ecology has increased recently based on research at known aggregation sites in the Indian, Atlantic, and Northeast Pacific Oceans; however, few data are available for the Northwest Pacific Ocean. This study provides a meta-analysis of 240 observations of white sharks from the Northwest Pacific Ocean between 1951 and 2012. Records comprise reports of bycatch in commercial fisheries, media accounts, personal communications, and documentation of shark-human interactions from Russia (n = 8), Republic of Korea (22), Japan (129), China (32), Taiwan (45), Philippines (1) and Vietnam (3). Observations occurred in all months, excluding October-January in the north (Russia and Republic of Korea) and July-August in the south (China, Taiwan, Philippines, and Vietnam). Population trend analysis indicated that the relative abundance of white sharks in the region has remained relatively stable, but parameterization of a 75% increase in observer effort found evidence of a minor decline since 2002. Reliably measured sharks ranged from 126-602 cm total length (TL) and 16-2530 kg total weight. The largest shark in this study (602 cm TL) represents the largest measured shark on record worldwide. For all countries combined the sex ratio was non-significantly biased towards females (1∶1.1; n = 113). Of 60 females examined, 11 were confirmed pregnant ranging from the beginning stages of pregnancy (egg cases) to near term (140 cm TL embryos). On average, 6.0±2.2 embryos were found per litter (maximum of 10) and gestation period was estimated to be 20 months. These observations confirm that white sharks are present in the Northwest Pacific Ocean year-round. While acknowledging the difficulties of studying little known populations of a naturally low abundance species, these results highlight the need for dedicated research to inform regional conservation and management planning.
authors.affiliation: Great Lakes Institute for Environmental Research, University of Windsor, Windsor, Ontario, Canada.
authors.forename: Heather M
authors.initials: HM
authors.lastname: Christiansen
authors.affiliation: Independent Researcher, Taipei, Taiwan.
authors.forename: Victor
authors.initials: V
authors.lastname: Lin
authors.affiliation: School of Marine Science and Technology, Tokai University, Shimizu, Shizuoka, Japan.
authors.forename: Sho
authors.initials: S
authors.lastname: Tanaka
authors.affiliation: Division of Marine and Freshwater Biological Resources, Sakhalin Research Institute of Fisheries & Oceanography, Yuzhno-Sakhalinsk, Russia.
authors.forename: Anatoly
authors.initials: A
authors.lastname: Velikanov
authors.affiliation: Moss Landing Marine Laboratories, Moss Landing, California, United States of America; Monterey Bay Aquarium, Monterey, California, United States of America.
authors.forename: Henry F
authors.initials: HF
authors.lastname: Mollet
authors.affiliation: KwaZulu-Natal Sharks Board, Umhlanga Rocks, South Africa; Biomedical Resource Unit, University of KwaZulu-Natal, Durban, South Africa.
authors.forename: Sabine P
authors.initials: SP
authors.lastname: Wintner
authors.affiliation: Shark Advocates International (a project of The Ocean Foundation), Washington, DC, United States of America.
authors.forename: Sonja V
authors.initials: SV
authors.lastname: Fordham
authors.affiliation: Great Lakes Institute for Environmental Research, University of Windsor, Windsor, Ontario, Canada.
authors.forename: Aaron T
authors.initials: AT
authors.lastname: Fisk
authors.affiliation: Great Lakes Institute for Environmental Research, University of Windsor, Windsor, Ontario, Canada.
authors.forename: Nigel E
authors.initials: NE
authors.lastname: Hussey
mesh_terms: D025041:Animal Migration; D000818:Animals; D003247:Conservation of Natural Resources; D005398:Fisheries; D010140:Pacific Ocean; D011156:Population Density; D012754:Sharks / Q000502:physiology*
references.citation: Nature. 2002 Jan 3;415(6867):35-6
references.pmid: 11780105
references.citation: PLoS One. 2010 Dec 17;5(12):e15465
references.pmid: 21253007
references.citation: PLoS One. 2012;7(2):e30492
references.pmid: 22355313
references.citation: Ecol Lett. 2010 Aug 1;13(8):1055-71
references.pmid: 20528897
references.citation: Science. 2005 Oct 7;310(5745):100-3
references.pmid: 16210537
references.citation: J Fish Biol. 2012 Apr;80(5):991-1018
references.pmid: 22497371
references.citation: Proc Biol Sci. 2010 Mar 7;277(1682):679-88
references.pmid: 19889703
references.citation: PLoS One. 2013;8(1):e55048
references.pmid: 23383052
references.citation: PLoS One. 2013 Jun 12;8(6):e66035
references.pmid: 23776600
references.citation: Elife. 2014;3:e00590
references.pmid: 24448405
references.citation: PLoS One. 2012;7(1):e30105
references.pmid: 22253893
references.citation: PLoS One. 2013 Jul 16;8(7):e68554
references.pmid: 23874668
references.citation: Biol Lett. 2009 Apr 23;5(2):156-9
references.pmid: 19324655
references.citation: Proc Biol Sci. 2011 Jun 7;278(1712):1679-86
references.pmid: 21084352
references.citation: Conserv Biol. 2007 Oct;21(5):1301-15
references.pmid: 17883495
references.citation: PLoS One. 2011;6(9):e24510
references.pmid: 21969858
references.citation: PLoS One. 2013 Aug 12;8(8):e71197
references.pmid: 23951111