Can circle hook use benefit billfishes?

Published source details Serafy J.E., Kerstetter D.W. & Rice P.H. (2009) Can circle hook use benefit billfishes?. Fish and Fisheries, 10, 132-142.
Share Tweet Email

Actions

This study is summarised as evidence for the following.

	Action	Category
	Use a different hook type Action Link

Use a different hook type

A systematic review study in 2009 of hook effects on non-target billfish species Istiophoridae spp. in pelagic commercial and recreational fisheries in the Atlantic and Pacific Oceans (Serafy et al. 2009) found that reductions in billfish mortality, but not catch rates, using circle hooks were found for four species compared to J hooks. No differences in catch rates (fish/1,000 hooks) between circle and J-shaped hooks were found in nine comparisons for the four species (white marlin Tetrapturas albidus, blue marlin Makaira nigricans and striped marlin Tetrapturus audax, and sailfish Istiophorus platypterus) in seven of seven studies. Three comparisons found reduced billfish mortality rates using circle hooks in three of seven studies, for: white marlin (circle: 0–48%, J-hook: 35–60%), blue marlin (circle: 53%, J-hook: 70%) and sailfish (circle: 33%, J-hook: 73%). However, seven other comparisons across five studies found no differences in mortality between hook types for each of the four billfish species. In addition, five of seven comparisons in five of six studies reported lower deep-hooking rates (associated with higher mortality) with circle hooks for white and striped marlin and sailfish, and two studies found no effect for white marlin. A quantitative review of hook effects (circle vs J hooks) on billfishes was conducted by searches of published and grey literature via library and electronic database records, as well as communications with agencies and individuals conducted by the author. Eleven studies reported species-specific hook data from commercial pelagic longline fisheries and recreational rod-and-reel fisheries.

(Summarised by: Khatija Alliji)