Title Measurement-points examination of circle hooks for pelagic longline fishery to evaluate e?ects of hook design
Authers Kosuke YOKOTA, Hiroshi MINAMI and Masashi KIYOTA
Keywords bycatch, circle hook, incidental catch, longline fishery, sea turtle
Citation Bull. Fish. Res. Agen. supplement No. 17, 83-102, 2006
Abstract
The use of circle hooks is regarded as one of the most effective methods to reduce incidental mortality of sea turtles in pelagic longline fishery as specified in the FAO Guidelines to Reduce Sea Turtle Mortality in Fishing Operations. Currently, many kinds of circle hooks are produced and distributed commercially. To introduce circle hooks wider in commercial fishery, the effect of hook specifications on catch rates of target and bycatch species as well as the practicality of its use should be clarified. We examined measurement points of circle hooks to compare their shape and size to evaluate the effect of hook design on catch rates of targeted and non-targeted species. We also give a brief summary on the possible effect of hook design on catch rate and survival of sea turtles. Using the measurement method, we describe shape, size and other characteristics of various circle hooks which we have collected for our mitigation experiments to facilitate the use of the hooks in scientific research and in commercial fishery and to assist information exchange on the results.
URI http://www.fra.affrc.go.jp/bulletin/bull/bull17/yokota.pdf