BOWERING: AGE, GROWTH, AND MATURITY OF GREENLAND HALIBUT 



50 



25 



20 

 15 - 

 10  

 5 



GREENLAND HALIBUT 

 BACK-CALCULATED GROWTH CURVES 

 HALE a FEMALE COMBINED 



AGE IYRS) 



FIGURE 6.— Comparisons of back-calculated growth curves (ages 1- 

 5) of Greenland halibut, sexes combined from seven areas of the 

 Canadian northwest Atlantic. 



decreased from 71.8 cm in the Baffin Bank area to 

 64.8 in the Saglek Bank area; however, the length at 

 M 5U increased to 73.1 cm in the Nain Bank area and 

 then to 80.9 cm in the Hamilton Bank area. The 

 length at M 50 for Northeast Newfoundland Shelf area 

 was 79.6 cm, very similar to the Hamilton Bank value. 

 The lowest length at M 50 was 57.8 cm for the Gulf of 

 St. Lawrence. 



The ages at M 50 calculated from the growth equa- 

 tions of Bowering (1978a) showed the same trends as 

 did the lengths at M 50 . The lowest age at M 5U was 7.8 

 yr for the Gulf of St. Lawrence data to a maximum of 

 12 yr for both Hamilton Bank-and Northeast New- 

 foundland Shelf. The results of the covariance analy- 

 ses for testing the regression coefficients (slopes) 

 and elevations (y-intercepts) of the fitted lines are 

 shown in Table 2. The slope of the Baffin Bank data 

 differed from that of Saglek Bank and Nain Bank but 

 not from those of any other areas. The slope of the fit- 



A-GULF OF ST LAWRENCE OIVS 4RST JAN - FEB 1978-60 (N = 513] 



B-SAGLEK6ANK OIV 2G SEPT 1978-79 (N = 682> 



C— BAFFIN BANK DIV 08 SEPT 1977 (N : 583) 



D- NAIN BANK DIV 2H SEPT 1978-79 IN = 612) 



E- NORTHEAST NFLD SHELF DIV 3K SEPT 1976 (N=736) 



F- HAMILTON BANK OIV 2J SEPT 1979 (N=577l 



FIGURE 7.— A comparison of sexual maturity ogives of female 

 Greenland halibut from six areas of the Canadian northwest 

 Atlantic. 



ted lines for Saglek Bank, Nain Bank, Hamilton 

 Bank, and Northeast Newfoundland Shelf did not 

 differ significantly. Biologically, this means that the 

 proportional increase of mature fish from one size 

 group to the next were the same for these areas. The 

 slope of the Gulf of St. Lawrence data differed signi- 

 ficantly from those of all areas except Hamilton Bank 

 and Baffin Bank. For paired comparisons which did 

 not yield significant differences between the slopes 

 of the fitted lines, statistical treatment of the el- 

 evations (y-intercepts) indicated highly significant 

 differences between the intercepts for all pairs at the 

 1% significance level (Table 2). This means that al- 

 though the proportional increase of mature fish from 



Table 2.— Matrix of r-values for paired comparisons of sexual maturity data for Greenland halibut. 



1 Indicates rejection of H at « 0.05. 

 'Indicates rejection of H »t » 0.01. 



607 



