A minimally invasive technique to assess several life‐history characteristics of the endangered great hammerhead shark Sphyrna mokarran. Issue 3 (1st February 2016)

• Record Type: Journal Article
• Authors: O'Connell, C. P.; Leurs, G.
• Is Part Of: Journal of fish biology. Volume 88:Issue 3(2016)
• Page Start: 1257
• Page End: 1264
• Publication Date: 2016-02-01
• Subjects: life‐history characteristics -- non‐invasive measurements -- Sphyrnidae; Fishes -- Periodicals; Fishes -- Great Britain -- Periodicals; 597
• DOI: 10.1111/jfb.12900
• Languages: English
• ISSNs: 0022-1112

Abstract

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.