170 
Fishery Bulletin 99(1 ) 
(Lindeboom, 1995; Bohnsack and Ault, 1996; Allison et 
al., 1998; Lauck et al., 1998; Yoklavich (ed.), 1998). Con- 
servation of ecological and demographic characteristics, 
protection of fish habitat, and ensuring recruitment 
supply under environmental uncertainty and manage- 
ment shortcomings are among the general benefits of 
harvest refugia. Harvest refugia may also serve as con- 
trol communities for comparison with nonrefuge areas, 
allowing us to determine the effects of exploitation on 
the ecological community and to disentangle the effects 
of fishing and environmental change. 
However, we still lack detailed and scientifically de- 
fensible knowledge regarding the effects of harvest 
refugia. Because of a lack of information on spatial 
processes for fish populations, there are only a few 
quantitative assessments of the effects of refugia on 
current yields and on future abundance of populations 
(Polacheck, 1990; Roberts and Polunin, 1991; DeMar- 
tini, 1993; Holland and Brazee, 1996). The primary in- 
formation needed for effective design of harvest refugia 
includes spatial structure of the population, population 
dynamics, larval drift trajectories, movements of ben- 
thic life stages, descriptions of fish habitats, and a dis- 
tribution of fishing effort. Limited amounts of such in- 
formation are available for shortraker and rougheye 
rockfish. Therefore, the establishment of harvest refu- 
gia in our study aims to improve the efficacy of the cur- 
rent harvest-rate strategy by providing a safer man- 
agement scheme by which to conserve shortraker and 
rougheye spawning populations from possible deple- 
tion. This scheme can be used in combination with the 
current management strategy as an additional control 
on harvesting and as an attempt to solve problems that 
characterize the current management policy. 
Bycatch season 
Shortraker rockfish 
Rougheye rockfish 
(1041 data points) 
(1285 data points) 
40 
• 
40 ■ 
30 
30 
• 
• 
20 
20 
• 
:! 
Jlfc. _ . 
^ 0 05 1 1.5 0 05 1 
XI 
O 
03 
O 
Prohibited season 
13 
03 
Shortraker rockfish 
Rougheye rockfish 
X 
(234 data points) 
(384 data points) 
40 
40 
30 
30 
20 
20 
10 
10 
itfln* 9 “* 
• • 
0 
0 0 5 1 
0 0 5 1 
Catch proportion 
Figure 1 
Haul catch of shortraker and rougheye rockfish and the pro- 
portion of the total catch made up by these species during the 
bycatch and prohibited season during 1991-96. 
Methods 
Documentation of fishery targeting practices 
Current management allows vessels to “top-off” their catch 
during the bycatch season. The purpose of the “bycatch 
season” is to protect the population from a directed fishery 
and to allow for “natural” bycatch in other directed fish- 
eries. In theory, targeting of a species can be avoided by 
allowing retention of only a certain fraction of that spe- 
cies, haul by haul. Such bycatch management measures 
have failed in instances where fishing deliberately targets 
bycatch species when their natural bycatch levels are lower 
than the specified limit. For example, if Pacific ocean perch 
(POP) is the target species, then vessels can retain bycatch 
species such as shortraker and rougheye rockfish up to a 
certain percentage of the total POP catch during the vessel 
trip. If they prefer, however, they could first fill their bins 
with POP and then target shortraker and rougheye rock- 
fish. Through “topping-off,” the fishery, in essence, becomes 
a directed fishery for the bycatch species. 
To examine the targeting practice for these bycatch spe- 
cies, historical fishing seasons were divided into an allow- 
able bycatch season and a prohibited season, and catch 
information for each fishing season was compared. Dur- 
ing the prohibited season, neither high catches nor high 
proportions of shortraker and rougheye rockfish occurred 
(Fig. 1). During the bycatch season, however, both high 
catches and high proportions were observed. This compar- 
ison supports the hypothesis that vessels do target high- 
value species and that their fishing practices are focused 
on specific “hot spot” areas. Higher catch-per-unit-of-effort 
(CPUE) points in regions of short-tow duration (Fig. 2) 
provide further evidence of the practice of targeting these 
species. As a result, serial targeting in productive areas 
would induce early attainment of the ABC and result in 
discarding afterwards. 
Design of harvest refugia 
Basic design components of marine refugia are location, 
size, shape, and number. These components depend on the 
purpose of the harvest refugia. 
In our application, the main goal of establishing harvest 
refugia for shortraker and rougheye rockfish is to protect 
adult fish from serial overfishing in areas of high short- 
