title: Long-term individual identification and site fidelity of white sharks,Carcharodon carcharias, off California using dorsal fins.
abstract: Mark-recapture techniques can be used to estimate white shark (Carcharodon carcharias) population abundance. These frameworks are based on assumptions that marks are conserved and animals are present at the sampling location over the entire duration of the study. Though these assumptions have been validated across short-time scales for white sharks, long-term studies of population trends are dependent on these assumptions being valid across longer periods. We use 22 years of photographic data from aggregation sites in central California to support the use of dorsal fin morphology as long-term individual identifiers. We identified five individuals over 16-22 years, which support the use of dorsal fins as long-time individual identifiers, illustrate strong yearly site fidelity to coastal aggregation sites across extended time periods (decades), and provide the first empirical validation of white shark longevity >22 years. These findings support the use of fin morphology in mark-recapture frameworks for white sharks.
authors.affiliation: P.O. Box 390, Inverness, CA 94937 USA.
authors.forename: Scot D
authors.initials: SD
authors.lastname: Anderson
authors.affiliation: Wildlife, Fish and Conservation Biology, University of California Davis, One Shields Ave, Davis, CA 95616 USA ; Max Planck Institute for Ornithology, Schlossallee 1a, 78315 Radolfzell, Germany.
authors.forename: Taylor K
authors.initials: TK
authors.lastname: Chapple
authors.affiliation: Hopkins Marine Station of Stanford University, 120 Oceanview Blvd., Pacific Grove, CA 93950 USA ; Monterey Bay Aquarium, 886 Cannery Row, Monterey, CA 93940 USA.
authors.forename: Salvador J
authors.initials: SJ
authors.lastname: Jorgensen
authors.affiliation: Wildlife, Fish and Conservation Biology, University of California Davis, One Shields Ave, Davis, CA 95616 USA.
authors.forename: A Peter
authors.initials: AP
authors.lastname: Klimley
authors.affiliation: Hopkins Marine Station of Stanford University, 120 Oceanview Blvd., Pacific Grove, CA 93950 USA.
authors.forename: Barbara A
authors.initials: BA
authors.lastname: Block