Reviews in Fish Biology and Fisheries

, Volume 27, Issue 1, pp 43–52 | Cite as

Review of effects of pelagic longline hook and bait type on sea turtle catch rate, anatomical hooking position and at-vessel mortality rate

  • Eric GilmanEmail author
  • Hsiang-Wen Huang


Bycatch in pelagic longline fisheries is one of the most serious threats to some sea turtle populations. Hook shape, hook minimum width and bait type have been the focus of research and management measures to mitigate problematic bycatch of vulnerable taxa. To assess the current state of knowledge and progress over the past decade, we reviewed findings on the effects of hook and bait type on pelagic longline sea turtle catch rates, anatomical hooking position and at-vessel mortality. Fish versus squid for bait lowered catch rates of leatherback sea turtles (Dermochelys coriacea) and individual species of hard shelled turtles. Fish bait also reduced hard-shelled turtle deep hooking. Wider circle hooks reduced both leatherback and hard-shelled turtle catch rates relative to narrower J and tuna hooks, and reduced the proportion of caught hard-shelled turtles that were deeply hooked. Wider circle hooks with fish bait reduced leatherback and hard-shelled turtle catch rates relative to narrower J and tuna hooks with squid bait. Wider versus narrower circle hooks reduced hard-shelled sea turtle catch rates and deep hooking. The mechanisms for hook and bait type effects on turtle interactions are reviewed. Research designed to assess single factor effects is needed, in particular for hook shape and minimum width, and for hook and bait effects on anatomical hooking position and survival rates. Fishery-specific and holistic assessments are needed to account for variability between fisheries in a bycatch mitigation method’s commercial viability, relative risks to affected populations and possible conflicting effects on vulnerable taxa.


Bycatch Circle hook Longline fisheries Sea turtle 



We thank the other participants of the 2016 Workshop on Joint Analysis of Sea Turtle Mitigation Effectiveness, and in particular the workshop chair Dr. Shelly Clarke, for adopting the recommendation to conduct this study to support the ABNJ project. We are grateful for substantial contributions made by Dr. Yonat Swimmer, US NOAA Fisheries, and for extremely helpful comments provided by peer reviewers.


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Copyright information

© Springer International Publishing Switzerland 2016

Authors and Affiliations

  1. 1.Hawaii Pacific UniversityHonoluluUSA
  2. 2.The Nature ConservancyMontereyUSA
  3. 3.Institute of Marine Affairs and Resource ManagementNational Taiwan Ocean UniversityKeelungTaiwan

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