Concordance of genetic and fin photo identification in the great white shark, Carcharodon carcharias, off Mossel Bay, South Africa

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.Electronic supplementary materialThe online version of this article (doi:10.1007/s00227-011-1643-5) contains supplementary material, which is available to authorized users.

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“…Similarly, Gubili et al (2009) used genetic data to show nearly 85% accuracy in experts matching dorsal fin photographs.…”

Section: Resultsmentioning

confidence: 99%

Long-term individual identification and site fidelity of white sharks, Carcharodon carcharias, off California using dorsal fins

et al. 2011

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“…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.…”

Section: Introductionmentioning

confidence: 99%

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

Tanaka¹,

Kitamura²,

Mochizuki³

et al. 2011

Mar. Freshwater Res.

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Abstract. The white shark, a top predator inhabiting the world's oceans, is an endangered species. However, knowledge of its life-history traits and population structure is still limited. We hypothesised that life-history traits would vary among populations because the species' various habitats are diverse and change through time. Age was estimated by counting growth bands in the centra of white sharks caught in Japan. The von Bertalanffy growth parameters were estimated at L N ¼ 455 cm TL, k ¼ 0.196 year À1 and t 0 ¼ À1.92 years for males and L N ¼ 607 cm TL, k ¼ 0.159 year À1 and t 0 ¼ À1.80 years for females. The growth rate to maturity was higher than that known for individuals from California and South Africa. Male sharks matured at 310 cm TL at 4 years of age and females began to mature at ,450 cm TL and 7 years. The D-loop-region sequences of mitochondrial DNA extracted from Japanese white sharks and GenBank datasets from sharks of California, Australia, New Zealand and South Africa indicate that Japanese white sharks form a monophyletic clade separate from the populations of other regions. The results suggest that unique life-history traits of Japanese white sharks may be caused by genetic differences.

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“…Alternatively, double tagging can also be achieved by using more than one identifying feature on species where patterns or scarring is reasonably stable; for instance using both sides of the animal, multiple designated areas on the body or by using a combination of natural markings and scarring (Domeier & Nasby‐Lucas, 2006; Meekan et al , 2006; Marshall et al , 2011). The best method, and one that adds considerable information to a study, is to add a completely separate analytical technique such as individual genotyping (Gubili et al , 2009; Clua et al , 2010). This may be the best technique to ensure the stability of patterns and hence ability to recognize individuals over longer time periods.…”

Section: Assumptions Of Photo‐identificationmentioning

confidence: 99%

The use and abuse of photographic identification in sharks and rays

Marshall

Pierce

2012

Journal of Fish Biology

155

142

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The use of photography to discriminate between individuals in a population using natural markings or aberrations is increasingly being utilized to support field research on elasmobranchs. This non-intrusive method has facilitated investigation of a wide variety of subjects including population composition, abundance estimates, residency and movement, demography and social behaviours. Here the first detailed review of photo-identification as a research technique for sharks and rays is provided, and its assumptions, current applications and potential highlighted. The limitations and practical considerations of photographic studies are also investigated with recommendations on initial survey design and ongoing data collection using current technology. Future directions are also explored with an emphasis on a move towards standardized approaches and automated recognition programmes to facilitate global collaborative work.

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Concordance of genetic and fin photo identification in the great white shark, Carcharodon carcharias, off Mossel Bay, South Africa

Cited by 40 publications

References 43 publications

Long-term individual identification and site fidelity of white sharks, Carcharodon carcharias, off California using dorsal fins

Long-term individual identification and site fidelity of white sharks, Carcharodon carcharias, off California using dorsal fins

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

The use and abuse of photographic identification in sharks and rays

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