Table 32.— Estimated biomass and population numbers of rock sole by subarea and for all subareas combined, 1976 Bering 



Sea spring trawl survey. 









Estimated 



Proportion 

 r>f total 



Estimated 



Proportion 

 of total 



Mean size 



Subarea' 



frequency of 

 occurrence 



CPUE 

 (kg/km) 



biomass 

 (t) 



estimated 

 biomass 



population 

 (millions) 



estimated 

 population 



Weight 

 (kg) 



TL 



(cm) 



Inner shelf 

 4N 



9.1 



0.39 



721 



0.003 



1.6 



0.002 



0.454 





4S 



23.2 



17.99 



77,708 



0.329 



218.2 



0.235 



0.356 



31.3 



1 



49.0 



6.86 



33,643 



0.143 



158.1 



0.170 



0.213 



26.0 



Outer shelf 



















and slope 



3 



67.5 



2.67 



12,514 



0.053 



58.4 



0.063 



0.214 



27.0 



3 Slope 

 2 



45.5 

 87.6 



0.26 

 29.67 



51 

 110,781 



< 0.001 

 0.469 



0.1 

 490.5 



<0.001 

 0.528 



0.415 

 0.226 



27.0 



2 Slope 



22.5 



1.52 



649 



0.003 



2.1 



0.002 



0.314 



30.4 



All subareas 

 combined 



54.0 



11.81 



=236,067 





928.9 





0.254 



27.8 



'See Figure 3. 



=95% confidence limits: 79,984-392,151 t. 



Table 33. — Estimated population size of rock sole age groups and year classes within survey subareas of the eastern Bering Sea, 1976 spring 



trawl survey. 



Subarea 1 



S3 4 5 6 7 8 9 10 11 12 13 14 

 — 1972 1971 1970 1969 1968 1967 1966 1965 1964 1963 1962 



1961 



2 16 Age All ages 



— unknown combined 



millions of fish 



Inner shelf 



4S 



1 

 Outer shelf 

 and slope 



3S 



2 



2 Slope 



4.28 3.67 



5.74 1.23 



1.17 14.95 23.75 21.00 41.00 48.11 36.67 19.22 2.94 2.04 1.67 

 6.64 43.11 27.87 13.03 19.93 18.33 13.40 5.43 0.92 0.76 0.35 



0.37 26.09 13.36 7.73 6.85 1.74 0.14 0.37 

 9.78 109.01 96.14 53.52 80.79 67.83 45.29 14.79 



1.97 



0.01 0.16 0.23 0.22 0.41 0.48 0.40 0.12 0.02 



1.57 0.55 

 0.02 — 



1.33 



1.32 



218.17 



0.21 



0.14 



158.07 





1.19 



58.39 



0.46 



1.85 



490.52 



— 



0.01 



2.07 



All subareas 





combined 10.02 4.90 17.97 19332 161.35 95.50 148.98 136.49 98.90 39.93 5.85 4.39 2.57 2.00 



4.51 928 



Proportion 





of total 0.011 0.005 0.019 0.209 0.174 0.103 0.161 0.147 0.107 0.043 0.006 0.005 0.003 0.002 



0.005 



'See Figure 3. 



2 Slope, the relative age distributions (sexes combined) were skewed 

 toward large, old (9, 10, and 11 yr) individuals. In subareas 1, 3S, 

 and 2, age groups 6 and 7 were predominant. 



Sex ratio. — The overall proportion of rock sole females was 

 0.55, with females more abundant than males in all geographical 

 areas (Table 34). Females dominated all age groups for subareas 

 combined except 6, 8, and 9 yr. Age groups 4, 1 1 yr, and older 

 were represented by particularly high proportions of females. 



Length-weight relationship. — A total of 707 individuals from 

 the rock sole populations in otolith areas A, B, and D were 

 measured for total length and weight (Table 35, Fig. 45). The 

 length-weight relationships of both male and female populations 

 significantly differed among the three regions. For both sexes, 

 heaviest weights-at-length were observed along the outer con- 

 tinental shelf in otolith areas B and D, followed by inner shelf 

 otolith area A. 



Significant differences were also found between male and 

 female populations in otolith areas A and D. In otolith area A, 

 females were approximately 24-36% heavier at length than males. 

 In otolith area D, females were approximately 13-69% heavier at 

 length. 



The overall relationship (W = 0.0026 Z,'- 4 "') was used for all 

 computations of population numbers. 



Age-length relationship and growth. — Age-length keys result- 

 ing from the 703 rock sole age determinations were developed and 

 the mean total length of age groups was determined. The total 

 number of otoliths collected in each area was otolith area A, 277; 

 otolith area B, 280; and otolith area D, 146. The data from otolith 

 areas A and B were combined to create a more complete age- 

 frequency table for the geographical regions of highest population 

 abundance. 



Results of the growth curve fittings are summarized in Table 36. 

 The data sets with selected ages seemed to give the best parameter 

 values, although the curve fittings for males and females in otolith 

 area D were determined using only three mean lengths-at-age. 



Overall (i.e., for otolith areas A, B, and D combined), male 

 rock sole showed a faster relative growth completion rate than 

 females, although the male asymptotic total length was only 85% 

 that of females (Table 36; Fig. 46). 



Comparisons of apparent growth characteristics between geo- 

 graphical regions are shown in Figure 47. Although the small 

 number of data points representing otolith area D certainly limits 

 conclusions, at the ages for which data were available from both 



61 



