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 Wn morphology as long-term individual identiWers. We identiWed Wve individuals over 16–22 years, which support the use of dorsal Wns as long-time individual identiWers, illustrate strong yearly site Wdelity to coastal aggregation sites across extended time periods (decades), and provide the Wrst empirical validation of white shark longevity >22 years. These Wndings support the use of Wn morphology in mark-recapture frameworks for white sharks.

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Cite this paper

@inproceedings{Anderson2011LongtermII, title={Long-term individual identification and site fidelity of white sharks, Carcharodon carcharias, off California using dorsal fins}, author={Scot D. Anderson and Taylor K. Chapple and Salvador J. Jorgensen and A. Peter Klimley and Barbara A. Block}, year={2011} }