370 
Fishery Bulletin 1 10(3) 
Table 7 
Estimates of weight-at-age parameters ( W^average maximum weight, K'=mean growth coefficient, < 0 =mean theoretical age a 
fish would have been at zero weight) for male sablefish (Anoplopoma fimbria) in Alaska determined with the von Bertalanffy 
model fitted to age-weight data for the pooled survey periods of 1996-2004 stratified by region and combined for Alaskan waters 
(W M = average maximum weight, ic=mean growth coefficient, f 0 =mean theoretical age a fish would have been at zero weight). 
Standard errors of the mean ( SE ) are presented in parentheses, p was fixed at 3 and is, therefore, not included in this table, n =the 
number of age-weight observations. 
k 
t 0 
RSS 
n 
All regions pooled 
3.2 (0.03) 
0.355 (0.01) 
-1.113 (0.18) 
152 
4889 
Aleutian 
3.3 (0.09) 
0.285 (0.03) 
-1.949 (0.50) 
38.1 
543 
Bering 
3.4 (0.07) 
0.313 (0.03) 
-1.630 (0.47) 
17.4 
363 
Chirikof 
3.1 (0.06) 
0.460 (0.07) 
0.019 (0.59) 
13.9 
294 
Kodiak 
3.0(0.03) 
0.762 (0.10) 
1.106(0.35) 
23.2 
542 
Shumagin 
3.3 (0.15) 
0.272 (0.04) 
-2.252 (0.73) 
18.3 
267 
Southeast 
3.2 (0.04) 
0.421 (0.03) 
0.019 (0.30) 
33.5 
605 
Table 8 
Estimates of weight-at-age parameters for female sablefish (Anoplopoma fimbria) determined with the von Bertalanffy model 
fitted to age-weight data for the pooled survey period of 1996-2004 stratified by region and combined for all Alaskan waters 
(W M = average maximum weight, r=mean growth coefficient, ( 0 =mean theoretical age a fish would have been at zero weight). 
Standard errors (SE) are presented in parentheses. P was fixed at 3 and is, therefore, not included in this table. n = the number 
of age-length observations. 
k 
*0 
RSS 
n 
All regions pooled 
5.5 (0.06) 
0.238 (0.01) 
-1.387 (0.13) 
277 
5767 
Aleutian 
5.5 (0.22) 
0.209 (0.02) 
-2.092(0.37) 
71.5 
795 
Bering 
4.7 (0.16) 
0.267 (0.02) 
-1.598 (0.42) 
34.2 
533 
Chirikof 
5.0 (0.12) 
0.326 (0.03) 
-0.206 (0.33) 
29.5 
485 
Kodiak 
5.2 (0.10) 
0.336 (0.02) 
-0.064 (0.27) 
42 
602 
Shumagin 
5.8 (0.33) 
0.197 (0.02) 
-2.349 (0.37) 
47.9 
563 
Southeast 
5.5 (0.11) 
0.300 (0.02) 
-0.114 (0.27) 
38.2 
515 
changes in sablefish growth. Arrowtooth flounder bio- 
mass likewise was unrelated to sablefish growth. Intra- 
specific, density-dependent effects appeared to be a more 
plausible explanation for changes in growth of Alaskan 
sablefish because measures of age-4+ biomass at some 
lags (in years) were correlated with reduced growth. 
Significant relationships included mean length at age 
6 regressed on the total age-4+ biomass (coefficient of 
determination [r 2 ] = 0.28, P=0.02), and mean length at 
age 4 regressed on the age-4 + biomass from 3 years prior, 
when the sablefish were age 1 (r 2 =0.5, P=0.04). Both of 
these analyses revealed a decrease in average length 
with an increase in biomass. Although not significant, 
a negative correlation between the growth coefficient k 
and both age-2 and age-4+ biomass also was evident. 
Management implications 
The use of updated growth data (length-at-age fitted to 
2 survey periods and weight-at-age from the more recent 
survey period) improved the fit of the current AFSC 
assessment model of sablefish to the data and slightly 
increased the recommended fishing-induced mortality. 
The updated growth also had an effect on the estimated 
time series of female spawning biomass (Fig. 5). Three 
prominent changes in the estimates of female spawn- 
ing biomass were observed when the assessment model 
that used the estimates of Sasaki (1985) was run with 
our updated growth estimates: 1) the initial estimated 
spawning biomass in 1960 was substantially higher, 2) 
the minima in female spawning biomass are lower, and 
3) the estimated spawning biomass was slightly lower 
for recent years (2000 to present). The increase, between 
the use of Sasaki estimates and our bias-corrected data, 
in estimated spawning biomass in 1960 is biologically 
reasonable because fishing mortality before 1960 was low 
(Hanselman et al., 2007). The lower spawning biomass 
minima in the updated series imply that the resource 
was not managed as conservatively as expected during 
the periods of lowest biomass. Results from our study 
