A minimally invasive technique to assess several life‐history characteristics of the endangered great hammerhead shark Sphyrna mokarran |
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| Authors: | C P O'Connell G Leurs |
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| Affiliation: | 1. O'Seas Conservation Foundation, Inc., Yonkers, NY, U.S.A.;2. Wageningen University and Research Centre, Wageningen, Netherlands |
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| Abstract: | A dorsal‐fin photo‐identification technique paired with a non‐invasive parallel laser photogrammetry technique was used to non‐invasively identify individual Sphyrna mokarran over time. Based on the data collected over a duration of 59 days, 16 different S. mokarran (mean ± s.d . pre‐caudal length: 220·82 ± 13·66 cm; mean ± s.d . cephalofoil width: 71·38 ± 7·94 cm) were identified using dorsal‐fin photo‐identification, with a mean ± s.d . shark re‐sighting frequency of 4·05 ± 3·06 at‐sea days. The results illustrate a high S. mokarran sighting rate and therefore, the utilization of parallel laser photogrammetry and dorsal‐fin photo‐identification may be a plausible multi‐year approach to aid in non‐invasively determining the growth rate and inter‐annual site fidelity of these animals. |
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| Keywords: | life‐history characteristics non‐invasive measurements Sphyrnidae |
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