Table 3.— Duncan multiple range test between months for large haddock from Georges Bank (underlined values are 

 homogeneous groups). 



Months 



Jan. 



July 



Mar. 



Feb. 



Sept. 



June 



Apr. 



Dec. 



Adjusted 

 means 



Individual 



1.4893 



1.4154 



1.2744 



1.2149 



1.2053 



1.1572 



1.1336 



1.0874 



comparisons 









of adjusted 











means 





















differences between samples from Browns 

 Bank and the western banks of Nova Scotia. 

 No significant differences were found between 

 these areas (Appendix Table A7). However, 

 comparisons were only possible between two 

 samples for each size category. 



A further series of covariance analyses were 

 made between samples from Georges Bank and 

 those for the Nova Scotian area within year 

 and month and size category strata. The pooled 

 analysis for large haddock showed a significant 

 difference in adjusted means in the Approxi- 

 mate F Test (Appendix Table A8). 



Months 



To investigate the variation between 

 months, all samples of large haddock from 

 Georges Bank were utilized for each month, as 

 yearly and area differences had been shown to 

 be nonsignificant. Only for this size category 

 and area were there enough data for a meaning- 

 ful comparison. These monthly regressions 

 were tested by covariance analyses and signifi- 

 cant differences were found among adjusted 

 means (Appendix Table A9). The adjusted 

 monthly means of the log e weights were then 

 computed and compared using the multiple 

 range test of Duncan (1955) with Kramer's 

 (1956, 1957) adjustment for unequal sized 

 samples and Finney's (1946) approximation 

 for the variance term. There were no seasonal 

 trends evident (Table 3). The lack of a seasonal 

 trend is contrary to the conclusion of Clark 

 and Dietsch (1959). 



CONVERSION OF DRESSED AND ROUND 

 WEIGHT FOR HADDOCK 



In the United States, haddock are almost 



invariably landed in a dressed condition. For 

 certain reports and research studies, it is 

 necessary to use round (whole) weights. This 

 section presents results of an analysis of avail- 

 able data to determine an estimator for con- 

 verting dressed weights to round weights. 



Lengths at Sea Versus Lengths Ashore 



The average length of the 199 fish was 524 

 mm with a standard error of 8.0 when mea- 

 sured fresh at sea and was 521 mm with a 

 standard error of 7.9 when measured after 

 landing. The ratio of length measured at sea to 

 that on shore was 1.005. The mean of the 

 difference between the paired measurements 

 was found to be within the realm of normal 

 error of measurement and, thus, fresh measure- 

 ments only were used in analysis. 



Difference Between Round and Dressed Weight 



The ratio of round weight (F') to dressed 

 weight (Y) for given length (X) may be 

 written: 



r = c^ x(b ' . b) 



c 



or 



Y C' 



(1) 



b)\og e X. (2) 



Linear regressions of (2) for each sample 

 are presented in Table 4. 



If the ratio of round to dressed weight does 

 not differ with length, the slope of the regres- 

 sion (b' -b) would equal zero, and the anti- 

 logarithm of logg-S- would be an estimate of 



