168 
Fishery Bulletin 1 10(2) 
Recreational 
Charter 
D Dolphinlish ( Coryphaena hippurus) 
Yellowfin tuna ( Thunnus albacares) 
F Wahoo {Acanthocybium solandri) 
iil 
Circle 
Hook type 
Figure 6 
Plots of the average proportion of fish that hooked up (±standard error) on circle hooks 
(open bars) and J hooks (gray bars). Data for plots includes hook-ups 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 [left column, panels A-C] and charter [right column, panels E-F]) and 
species (dolphinfish [Coryphaena hippurus ] [A, D], yellowfin tuna [Thunnus albacares ] 
[B, E], 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. 
rate on circle hooks was significantly higher than J 
hooks in a dead bait troll fishery for sailfish. The abil- 
ity for the angler to visually see the fish with the bait 
in its mouth may allow for higher hook-ups on circle 
hooks in that fishery. In contrast, fishing for yellowfin 
tuna and wahoo involved using a heavy drag because 
the fish are aggressive and generally hook themselves 
upon striking (see Graves and Horodysky [2010] for a 
similar description and approach when targeting blue 
marlin). Theoretically, the circle hook should work in 
this heavy-drag situation only if the fish’s mouth is at 
an angle to the direction of the line when the bait is 
taken into the mouth. Hook-up rates for yellowfin tuna 
and wahoo were slightly higher on J hooks on charter 
trips (for which we had the most data); this finding may 
be a result of some strikes on circle hooks where the 
mouth opening faced the direction that the bait was be- 
ing trolled or because of bait rigging (see below). Graves 
