Rudershausen et al A comparison between circle hook and J hook performance in the troll fisheries off North Carolina 
165 
Recreational 
Charter 
Hook type 
Figure 4 
Plots of the average number of strikes per trip (±standard error) on circle hooks (open 
bars) and J hooks (gray bars). Data for plots includes strikes from unidentified fish 
later apportioned to species that could be identified. Data for each species are from both 
directed and nondirected trips for that species. Plots are broken down by user group 
(recreational lleft column, panels A-C] and charter I right column, panels D-F]) and 
species (dolphinfish [ Coryphaena hippurus] |A, D], yellowfin tuna [ Thunnus albacares] 
[B, E 1 , and wahoo ( Acanthocybium solandri ] [C, F]). The legend denoting fill pattern for 
each leader type applies to all panels. No bar for a particular hook-type + species+user- 
group + leader-type combination indicates no catch. 
size calculations) indicate that fishermen can expect 65% 
greater catches of the three species or taxa groups on J 
hooks than on circle hooks. The similar findings between 
the species and taxa analyses indicate that morphologi- 
cal features of fish, attack styles, and hook effectiveness 
are consistent among the species of the tuna group and 
among the species of the mackerel group. Additionally, 
the similar results when smaller tunas and mackerels 
were included in the taxa analysis indicate that the inef- 
fectiveness of circle hooks compared with J hooks is not 
size dependent within the range of fish sizes in our study. 
The similarities between our findings and prior hook 
comparisons of hooks on longlines depend on the species 
being considered. In a Brazilian longline fishery, Sales 
et al. (2010) found a similar trend in dolphinfish catches 
to that found in our study (lower catches on circle hooks 
than on J hooks) but significantly more tunas caught 
on circle hooks than on J hooks. The increased catch 
