Article

Species identification of the shark involved in the 2007 Lifou fatal attack on a swimmer: A reply to Tirard et al. (2015)

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  • IRD (Institut de Recherche pour le Développement)
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Abstract

Based on new photographs of the wound, Tirard et al. (2015) tried to demonstrate that the shark involved in a fatal attack on a human in Lifou in 2007 had homodont teeth and that it sawed the femur instead of directly cutting it, promoting the hypothesis that it was a tiger shark instead of a white shark. They also contested the data provided by the direct witness of the attack about the behaviour of the shark, specific to this former species. The evidences they provide are not convincing and, based on the absence of tissue loss and description of a jumping behaviour, we still believe that it was a single bite-and-spit attack by a white shark.

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... Case study A: description of the wound on a 23-year-old female fatally bitten in a shallow water lagoon in New Caledonia. This case study was adapted from [42][43][44] (same case). ...
... The hypothesis of the white shark should then prevail. Also, based on behavioural features of the attack (provided by a witness), Clua and Séret [42,43] concluded that the candidate species for this 2007 attack in Lifou Island was a white shark and not a tiger shark as supported by Tirard et al. [44]. This choice seems to be supported by the tools provided by Lowry et al. [40]. ...
... As a consequence, the species involved is not positively identified in ~70% of global shark bite incidents (data from the International Shark Attack Files, 2010-2019 bites; floridamuseum.ufl.edu/shark-attacks/). It may be possible to use bite impressions left in victims or their apparel or accessories (e.g., wetsuits or surfboards) to identify culprit species, but even experts using this approach have disagreed over the interpretation of bite impressions [4][5][6][7][8]. Modern DNA technology provides a potential tool for definitive species identification provided sufficient DNA is transferred from the shark to the victim or victim's articles (e.g., surfboard, wetsuit, paddle) and adheres despite immersion in seawater. ...
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... Assignments to the species for the sharks involved in attacks are thus difficult and often disputable (e.g. [21][22][23]), and may be influenced by individual experiences, and knowledge of previous attack history at the site. Additionally, observations and wound characteristics only bring limited information about the individual such as an estimate of its size and rarely discriminant marks. ...
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