Comparison of circle hook and J hook catch rate for target and bycatch species taken in the Korean tuna longline fishery

Effects of circle hooks on pelagic catches in the Hawaii-based tuna longline fishery

“…Catchability on 18/0 circle hooks in our study was reduced for incidental and bycatch species compared to J-hooks which is in contrast to most studies, especially for billfish. No significant catchability differences were demonstrated between circle and J-hooks in 6 longline comparisons (see review Serafy et al, 2009) based on 3 species (sailfish, white marlin and blue marlin) in 3 studies Kim et al, 2006;Diaz, 2008). Mean catch rate was higher (0.26 billfish per 1000 hooks) on J-hooks and the lack of statistical differences may be related to the hook types -9/0 J-hook and 16/0 circle hook , 4/0 J-hook, 15/0 and 18/0 circle hook (Kim et al, 2006) or insufficient sample sizes.…”

“…No significant catchability differences were demonstrated between circle and J-hooks in 6 longline comparisons (see review Serafy et al, 2009) based on 3 species (sailfish, white marlin and blue marlin) in 3 studies Kim et al, 2006;Diaz, 2008). Mean catch rate was higher (0.26 billfish per 1000 hooks) on J-hooks and the lack of statistical differences may be related to the hook types -9/0 J-hook and 16/0 circle hook , 4/0 J-hook, 15/0 and 18/0 circle hook (Kim et al, 2006) or insufficient sample sizes. No significant catchability differences were demonstrated between 18/0 circle and J-hooks for 4 of 5 billfish species in the western Atlantic (Pacheco et al, 2011).…”

SIZE AND FISHING GROUND OFWAHOO (Acanthocybium solandri Cuvier, 1832) FROM CATCH DATA OF TUNA LONGLINE OPERATED IN INDIAN OCEAN

“…The hook rate is higher compared to the hook rate of wahoo on the tuna long line operated in Pacific Ocean as reported by Kim et al (2007) that the hook rate on the tuna long line operated in Pacific Ocean was 0.446 per 1.000 hooks. The other previous research noted that only 12 wahoo were caught during 5,500 hours of surface trolling in the open sea, more than 60 miles from coastal (Murphy & Ikehara 1955: 14).…”

Ecological risk assessment of the Marshall Islands longline tuna fishery

“…Several studies have documented no significant effect [147][148][149][150][151][152][153][154][155], significantly higher [146,152,153,[155][156][157][158][159][160], and significantly lower [147,154,161,162] catch rates of some elasmobranch species on circle hooks relative to catch rates on J or tuna hooks. Several of these studies, however, did not employ methods that enabled a determination of the effect of the single factor of hook shape on catch rates, where experiments included treatments with differences in multiple factors (e.g., hook shape and width), and analyses of observer program data did not explicitly account for potentially significant explanatory factors through the development of standardized catch rate models [49].…”