Philopatry and migration of Pacific white sharks

Abstract

Advances in electronic tagging and genetic research are making it possible to discern population structure for pelagic marine predators once thought to be panmictic. However, reconciling migration patterns and gene flow to define the resolution of discrete population management units remains a major challenge, and a vital conservation priority for threatened species such as oceanic sharks. Many such species have been flagged for international protection, yet effective population assessments and management actions are hindered by lack of knowledge about the geographical extent and size of distinct populations. Combining satellite tagging, passive acoustic monitoring and genetics, we reveal how eastern Pacific white sharks ( Carcharodon carcharias ) adhere to a highly predictable migratory cycle. Individuals persistently return to the same network of coastal hotspots following distant oceanic migrations and comprise a population genetically distinct from previously identified phylogenetic clades. We hypothesize that this strong homing behaviour has maintained the separation of a northeastern Pacific population following a historical introduction from Australia/New Zealand migrants during the Late Pleistocene. Concordance between contemporary movement and genetic divergence based on mitochondrial DNA demonstrates a demographically independent management unit not previously recognized. This population's fidelity to discrete and predictable locations offers clear population assessment, monitoring and management options.

Age, growth and genetic status of the white shark (Carcharodon carcharias) from Kashima-nada, Japan

“…This shark was a maturing female of 446.3 cm TL. The neighbour-joining tree showed two major groups: South Africa and the other regions, as described by Pardini et al (2001) and Jorgensen et al (2010). Japanese white sharks were included in the latter group and formed a definite monophyletic cluster separate from California, Australia and New Zealand populations (bootstrap value 89%).…”

“…Pardini et al (2001) and Jorgensen et al (2010) found genetic differences among white shark populations of South Africa, Australia-New Zealand and California. The present neighbourjoining tree differed slightly from Jorgensen's tree in the relationship between Australia-New Zealand and California.…”

“…ver.1.4.4 (Nylander 2004). A neighbour-joining tree was drawn with Mega ver.3 using the genetic distances calculated by the Kimura 2-parameter (K2P) method (Kimura 1980;Saitou and Nei 1987;Kumar et al 2004), including previously published datasets from California (Jorgensen et al 2010; Accession Nos. GU2302-GU2321), Australia, New Zealand and South Africa (Pardini et al 2001; Accession Nos.…”

“…Recently, the movements, habitat features and population structure of white sharks around South Africa, Australia, New Zealand and California have been studied using electronic tags and DNA analysis techniques (Bonfil et al 2005(Bonfil et al , 2010Gubili et al 2009;Jorgensen et al 2010). These studies reveal that white sharks move over large spatial areas: South Africa to Australia, New Zealand to Australia and California to Hawaii.…”

A Census of Fishes and Everything They Eat: How the Census of Marine Life Advanced Fisheries Science

“…Gathering information from animals in these hotspots not only generates oceanographic information from undersampled areas but identifies multispecies critical habitat (McIntyre 2010). Another remarkable example of a general behavioral pattern that was only discovered because of extensive, simultaneous tagging of many species is that site fidelity and round-trip migrations are shown by most top predators, including great white sharks (Carcharodon carcharias), which occupy a common area offshore but return to coastal home territories (Jorgensen et al 2010). …”