Double tagging clarifies post-release fate of great hammerheads (Sphyrna mokarran)

Abstract Background Biotelemetry applications have advanced our understanding of many highly migratory species, but present a challenge for species that suffer high capture and/or post-release stress. Failing to accurately characterize post-release fate can obfuscate our understanding of animal move...

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Main Authors: J. Marcus Drymon, R. J. David Wells
Format: Article
Language:English
Published: BMC 2017-12-01
Series:Animal Biotelemetry
Subjects:
Online Access:http://link.springer.com/article/10.1186/s40317-017-0143-x
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author J. Marcus Drymon
R. J. David Wells
author_facet J. Marcus Drymon
R. J. David Wells
author_sort J. Marcus Drymon
collection DOAJ
description Abstract Background Biotelemetry applications have advanced our understanding of many highly migratory species, but present a challenge for species that suffer high capture and/or post-release stress. Failing to accurately characterize post-release fate can obfuscate our understanding of animal movement patterns and complicate the development of effective conservation and management plans. The great hammerhead (Sphyrna mokarran) is a long-lived, highly migratory shark listed by the International Union for the Conservation of Nature as Endangered. Accordingly, we used a combination of tags designed to report horizontal position estimates and verify post-release fate, to examine movements of great hammerheads in the northern Gulf of Mexico. Results Between May and September 2016, three individuals (one male and two females) were equipped with both fin-mounted smart position and temperature transmitting (SPOT) tags and survivorship pop-off archival tags (sPAT) to provide information on post-release fate. Tagged sharks measured 187 (F), 203 (M), and 250 (M) cm total length. All three sharks surfaced daily, yet individuals showed variability in vertical habitat use, with maximum daily depths ranging from 5 to 98 m. A single fin-mounted SPOT tag, attached to the smallest of the three sharks, reported position estimates over an 81-day period and moved a straight-line distance of approximately 400 km; however, the other two fin-mounted SPOT tags failed to generate position estimates. All three sPAT tags indicated post-release survival. Final positions of the sPAT tags from the two largest sharks suggested restricted horizontal movements (< 35 km). Conclusions Despite their demonstrated utility on other shark species that frequent the surface, fin-mounted SPOT tags may not be the best option for tracking great hammerheads. In addition, our findings illustrate the value of double-tagging animals under certain conditions; notably, over the short monitoring period of this study, one of the three sharks tagged may have been incorrectly presumed dead had only a fin-mounted SPOT tag been used.
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spelling doaj.art-39074a2f9a114b4789b8d566f46e76312022-12-21T23:24:45ZengBMCAnimal Biotelemetry2050-33852017-12-01511710.1186/s40317-017-0143-xDouble tagging clarifies post-release fate of great hammerheads (Sphyrna mokarran)J. Marcus Drymon0R. J. David Wells1Coastal Research and Extension Center, Mississippi State UniversityDepartment of Marine Biology, Texas A&M University at GalvestonAbstract Background Biotelemetry applications have advanced our understanding of many highly migratory species, but present a challenge for species that suffer high capture and/or post-release stress. Failing to accurately characterize post-release fate can obfuscate our understanding of animal movement patterns and complicate the development of effective conservation and management plans. The great hammerhead (Sphyrna mokarran) is a long-lived, highly migratory shark listed by the International Union for the Conservation of Nature as Endangered. Accordingly, we used a combination of tags designed to report horizontal position estimates and verify post-release fate, to examine movements of great hammerheads in the northern Gulf of Mexico. Results Between May and September 2016, three individuals (one male and two females) were equipped with both fin-mounted smart position and temperature transmitting (SPOT) tags and survivorship pop-off archival tags (sPAT) to provide information on post-release fate. Tagged sharks measured 187 (F), 203 (M), and 250 (M) cm total length. All three sharks surfaced daily, yet individuals showed variability in vertical habitat use, with maximum daily depths ranging from 5 to 98 m. A single fin-mounted SPOT tag, attached to the smallest of the three sharks, reported position estimates over an 81-day period and moved a straight-line distance of approximately 400 km; however, the other two fin-mounted SPOT tags failed to generate position estimates. All three sPAT tags indicated post-release survival. Final positions of the sPAT tags from the two largest sharks suggested restricted horizontal movements (< 35 km). Conclusions Despite their demonstrated utility on other shark species that frequent the surface, fin-mounted SPOT tags may not be the best option for tracking great hammerheads. In addition, our findings illustrate the value of double-tagging animals under certain conditions; notably, over the short monitoring period of this study, one of the three sharks tagged may have been incorrectly presumed dead had only a fin-mounted SPOT tag been used.http://link.springer.com/article/10.1186/s40317-017-0143-xSPOTsPATPost-release mortalityMovement
spellingShingle J. Marcus Drymon
R. J. David Wells
Double tagging clarifies post-release fate of great hammerheads (Sphyrna mokarran)
Animal Biotelemetry
SPOT
sPAT
Post-release mortality
Movement
title Double tagging clarifies post-release fate of great hammerheads (Sphyrna mokarran)
title_full Double tagging clarifies post-release fate of great hammerheads (Sphyrna mokarran)
title_fullStr Double tagging clarifies post-release fate of great hammerheads (Sphyrna mokarran)
title_full_unstemmed Double tagging clarifies post-release fate of great hammerheads (Sphyrna mokarran)
title_short Double tagging clarifies post-release fate of great hammerheads (Sphyrna mokarran)
title_sort double tagging clarifies post release fate of great hammerheads sphyrna mokarran
topic SPOT
sPAT
Post-release mortality
Movement
url http://link.springer.com/article/10.1186/s40317-017-0143-x
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