subarea 2 Slope, where 30.3% of the apparent population was 6 

 yr or older. 



Sex ratio. — The overall proportion of arrowtooth flounder 

 females was 0.56, and females were more abundant than males in 

 all geographical regions (Table 58). With the exception of the 4-yr 

 group, females were more abundant at all ages, particularly 

 dominating at 7 yr and older. 



sample sizes. For females, the inclusion or exclusion of the mean 

 fork lengths of the 10- and 12-yr age groups gave markedly dif- 

 ferent results. The L x and t values obtained from the all-ages 

 data set seemed most realistic. 



The results from both data sets indicated a growth pattern of 

 female arrowtooth flounder having approximately a 70-80% (or 

 greater) larger asymptotic fork length than males and slower 

 relative growth completion rate. 



Length-weight relationship. — A total of 282 individuals from 

 the arrowtooth flounder populations in otolith areas B and D 

 were measured for fork length and weight (Fig. 72, Table 59). The 

 overall relationship obtained was $ = 0.0072 Z, 31028 . No 

 statistically significant difference was found between the length- 

 weight characteristics of male and female populations. 



Age-length relationship and growth. —The age-length observa- 

 tions from otolith areas B (358 samples) and D (25 samples) were 

 combined to create more complete age-frequency tables. Results 

 of the growth curve fittings are summarized in Table 60 and 

 Figure 73. Both data sets (all ages and selected ages) gave approxi- 

 mately the same results for males, although the mean fork lengths 

 of the 7- and 8-yr age groups were outlying values due to small 



Pacific halibut. 



Distribution and abundance.—- Pacific halibut showed a pri- 

 marily deepwater distribution pattern, occurring from southern to 

 northern limits of the survey area at bottom depths > 79-90 m 

 (Fig. 74). Overall, Pacific halibut were taken at 161 (37.0%) of the 

 435 grid sampling stations, at a mean abundance of 1.57 kg/km 

 trawled (Table 61). Approximately 90% of the apparent popula- 

 tion biomass was located in subareas 2 and 2 Slope (combined) 

 along the outer edge of the continental shelf between Unimak and 

 St. George Islands. Only low densities were observed in Bristol 

 Bay, along the inner and central shelf regions, and north of the 

 Pribilof Islands. 



Table 58. — Proportions of females in the estimated population of arrowtooth flounder by age group and 

 geographical area, 1976 Bering Sea spring trawl survey. 1 



Age group (yT) 



Subarea 1 



S3 



All ages 

 combined 



Outer shelf 















and slope 















3 Slope 



0.73 



0.74 



0.65 



0.53 



0.42 



0.20 



2 



0.51 



0.47 



0.53 



0.50 



0.88 



0.41 



2 Slope 



0.67 



0.51 



0.75 



0.78 



0.93 



0.96 



1.00 



1.00 



1.00 



0.71 

 0.52 

 0.68 



All subareas 



combined 0.53 



0.49 0.61 0.66 



0.91 



0.94 1.00 



1.00 



1.00 



0.56 



Based upon sampled individuals for which sexes could be determined. The population in subarea 3 is not 

 included because no length-frequency data were collected. 

 2 See Figure 3. 



Table 59.— Length-weight relationships observed for arrowtooth flounder during the 1976 Bering Sea spring trawl 

 survey, with testing for between-sex differences. 









FL 















Otolith 



Number 



range 



Length-weight coefficients 



Predicted weight-at- 



length 



Sex 



area' 



sampled 



(cm) 



a 



b 



10 cm 



25 cm 



45 cm 

























grams 





Males 



B 



57 



20-55 



0.0106 



2.9840 



10.1 



156.6 



905.1 





D 



11 



34-47 



n.d. 1 



n.d. 



n.d. 



n.d. 



n.d. 





Both areas 



















combined 



68 



20-55 



0.0098 



3.0061 



9.9 



156.3 



915.0 



Females 



B 



200 



18-64 



0.0074 



3.0970 



9.2 



157.9 



974.9 





D 



14 



35-66 



n.d. 



n.d. 



n.d. 



n.d. 



n.d. 





Both areas 



















combined 



214 



18-66 



0.0071 



3.1054 



9.1 



156.8 



973.1 



Overall 





282 



18-66 



0.0072 



3.1038 



9.0 



155.9 



966.1 



Analysis 



of covariance 



























Tests for differences 











Slope (b) 







Common means 







df 





F ratio 



df 





F ratio 



Between 



sexes in area B 





1:253 





1.20 



1:254 





1.49 



Between 



sexes in both areas 



combined 



1:278 





1.20 



1:279 





1.59 



'See Figure 4. 

















'n.d 



. = not determined due to limited samp 



[e size. 











101 



