416 
Fishery Bulletin 113(4) 
the reference points in the base scenario (SI). A simi- 
lar outcome was seen in a per-recruit analysis of long- 
tail tuna (T. tonggol ) in Australian waters, whereby 
increases in recreational size limits and post-release 
survival did not change the relationship between F cur . 
rent and biological reference points (Griffiths, 2010). It 
is likely that this finding results from low selectivity 
of immature fish of both species in recreational fisher- 
ies. In contrast, the recreational fishery for largemouth 
queenfish ( Scomberoides commersonnianus ) in Austra- 
lian waters had a relatively high selectivity for imma- 
ture fish; therefore, increasing minimum size limits to 
reflect L 50 had a drastic improvement on the status of 
that stock (Griffiths et ah, 2006). 
Future directions 
We compared Current for wahoo against tradition- 
ally used reference points for target species in com- 
mercial fisheries. Alternative reference points, such 
as catch rate, mortality rate, and potential biological 
removal, have been suggested for data-poor bycatch 
species (Moore et al., 2013). However, because wahoo 
represent an important byproduct in the 2 commercial 
fisheries assessed in this article, reference points based 
on yield may still be appropriate. Management objec- 
tives for recreational fisheries, which generally value 
high catch rates and large average size of fish, differ 
from those for commercial fisheries, which value total 
yield and high profit. In regions where recreational 
fisheries represent a significant proportion of total F 
for wahoo, alternative reference points that reflect the 
preferences of these fisheries (e.g. more large fish) may 
be appropriate. 
Per-recruit analysis cannot directly explore the ef- 
fect of reducing catch and effort on the status of a 
stock. However, input (effort-based) and output (catch- 
based) management measures are commonly used in 
both commercial and recreational fisheries. For ex- 
ample, the efficacy of current commercial trip limits 
or recreational possession limits for wahoo could not 
be examined with per-recruit analysis. A population 
model should be adopted in future assessments of this 
species in the southwest Pacific Ocean, such as MUL- 
TIFAN-CL (Fournier et al., 1998; Kleiber et al., 2003), 
that is structured by size, age, and spatial distribution. 
This model can integrate fishery-specific catch, effort, 
and length-frequency data, as well as tag and release 
data, to provide time-series estimates of recruitment, 
biomass, and F, as well as to summarize the stock sta- 
tus against various reference points. 
This approach has been used extensively for pelagic 
target species in commercial fisheries throughout the 
western and central Pacific Ocean (Davies et al. 9 ; Hoyle 
9 Davies, N., S. Hoyle, S. Harley, A. Langley, P. Kleiber, and J. 
Hampton. 2011. Stock assessment of bigeye tuna in the 
western and central Pacific Ocean. Western and Central 
Pacific Fisheries Commission WCPFC-SC7-2011/SA- WP-02, 
119 p. [Available at website.] 
et al. 10 ; Langley et al. 11 ). Although such assessments 
are data intensive and, therefore, costly to implement, 
they allow management strategy evaluations to explore 
outcomes for fishery and population sustainability ob- 
jectives. Alternatively, cost-effective methods for assess- 
ing all species that a fishery interacts with, such as the 
quantitative ecological sustainability assessment for 
fishing effects developed by Zhou and Griffiths (2008), 
may be more appropriate for wahoo and other byprod- 
uct and bycatch species. 
Although wahoo may still be considered a low-prior- 
ity species for most commercial fisheries, their steadily 
increasing catches worldwide may require species-spe- 
cific management in the future. We collated biological 
and fishery information for wahoo in the southwest 
Pacific Ocean and present the first quantitative as- 
sessment of their status in this region. The results 
of this assessment indicate that F current for wahoo is 
lower than limit reference points and the target refer- 
ence point for Y/R and that it is slightly higher than 
the target reference point for SBB/R. It is important 
that these fisheries be re-assessed periodically because 
their dynamics (e.g., effort, catch, or management ar- 
rangements) may change through time. In addition to 
providing a baseline assessment for wahoo, this study 
provides an approach that may be useful for data-poor, 
nontarget species in other fisheries worldwide. 
Acknowledgments 
We thank the Australian Fisheries Management Au- 
thority and Secretariat of the Pacific Community for 
providing catch, effort and, size-frequency data from 
commercial fisheries. We would like to thank 3 anon- 
ymous reviewers for constructive feedback that im- 
proved the quality of the final manuscript. We also 
thank I. Tibbetts (UQ) for comments on an earlier draft 
of the manuscript. M.T.Z was funded by a University 
of Queensland Research Scholarship, with support pro- 
vided by the Division of Marine and Atmospheric Re- 
search of the Commonwealth Scientific and Industrial 
Research Organisation. 
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