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Fishery Bulletin 1 10(3) 
Figure 1 
Map showing the 6 management regions covered by the NMFS sablefish (Ano- 
plopoma fimbria) longline survey during the period of 1981-2004 and used 
for growth comparisons in our study: eastern Bering Sea, Aleutian Islands, 
and the Gulf of Alaska management regions of Shumagin, Chirikof, Kodiak, 
and Southeast. Underlined regions are those considered to be in the Gulf of 
Alaska. Triangles represent individual survey stations. 
of one of these fishes suggests that an update of the 
assessment of the other fish is needed. 
A growth analysis of sablefish in the Gulf of Alaska 
(Sigler et ah, 1997) revealed values similar to results 
from the earlier analysis by Sasaki (1985); therefore, 
the earlier growth estimates for sablefish in Alaska 
have continued to be used in models for sablefish stock 
assessment. In the last 20 or more years, however, more 
sablefish from a wide geographic area have been aged 
and another evaluation of growth is warranted. 
The overall goal for this study was to evaluate wheth- 
er changes in growth of sablefish in Alaska have oc- 
curred since 1985. Specifically, our objectives were 1) 
to reevaluate estimates of length at age and weight at 
age, 2) to compare these new estimates among regions 
and over time for each sex, 3) to evaluate the sensitivity 
of the current stock-assessment model using this new 
growth information and evaluate the implications for 
management of sablefish in Alaska, and 4) to search for 
biological or environmental reasons for any discovered 
changes. 
Materials and methods 
Data collection 
We used data available from the annual longline survey 
conducted cooperatively by the Fisheries Agency of 
Japan (1981-94) and the NMFS Alaska Fisheries 
(AFSC) (1988-present). The Fisheries Agency of Japan 
conducted the survey solely from 1981 to 1987. Starting 
in 1988, the NMFS conducted the survey cooperatively 
with Japan between 1988 and 1994, creating survey 
overlap between the efforts of the 2 countries. NMFS 
took over conducting the survey solely in 1995. Samples 
were collected from June through September, 1981 
to 2004, in all 6 management regions defined by the 
North Pacific Fishery Management Council (NPFMC). 
Four of these regions are in the Gulf of Alaska (GOA): 
Southeast, Kodiak, Chirikof, and Shumagin. The other 
2 management regions are in the eastern Bering Sea 
(EBS) and Aleutian Islands (AI) (Hanselman et ah, 
2010; Fig. 1). Predefined stations have been sampled 
along the upper continental slope at depths of 200-1000 
m in the GOA annually from 1981 to the present and 
in the BSAI at 2 different schedules annually from 
1981 to 1994 and in alternating years from 1996 to 
the present (EBS in odd years and AI in even years). 
At each station, 7200 hooks baited with cut squid 
( Illex spp.) and spaced 2 m apart are set (Sigler and 
Fujioka, 1988). 
Length measurements and otoliths of sablefish have 
been collected since the inception of the Japan-U.S. 
cooperative longline survey in 1981, and data collection 
has continued as part of the current NMFS domestic 
longline survey that started in 1988. However, these 
data were collected under 2 different sampling designs. 
