FISHERY BULLETIN: VOL. 86, NO. 1 



Table 3. — Geometric nriean CPUE^ (landings per day fished, metnc tons) for Georges Bank, 

 Southern New England, and Cape Cod yellowtail flounder tnps by depth zone, 1964-83. 



20nly one tnp in depth zone 3 in 1970 on Cape Cod grounds. 



corresponding to medium and small vessels, par- 

 ticularly in the later years (Table 2). The initial 

 ANOVAs performed over all statistical areas re- 

 vealed highly significant iP < 0.01) differences in 

 CPUE for tonnage class and area main effects in 

 each of the 20 years (Table 4). The interaction of 

 tonnage class and area was also highly signifi- 

 cant in all years, suggesting that relative fishing 

 power of the individual vessel classes varies ac- 

 cording to area. ANOVA results for the compari- 

 son of CPUE among stocks were highly signifi- 

 cant for area main effects in 19 out of 20 years, 

 and the tonnage class-stock area interaction term 

 was highly significant in all years (Table 4). 

 Grouping the data according to stock tended to 

 reduce the amount of significant tonnage class- 

 area interaction within each stock, although dif- 

 ferences among tonnage classes remained highly 

 significant. 



On Georges Bank the differences in CPUE were 

 highly significant for statistical area and tonnage 

 class main effects in 80 and lOO'/r of the years, 

 respectively, while the tonnage class-area inter- 

 action was highly significant in only 40% of the 

 years. Differences due to area on Southern New 

 England grounds were highly significant in all 

 years except 1978, and differences due to tonnage 

 class were highly significant in all years. The in- 

 teraction term was highly significant in 70% of 



the years. Differences due to area on the Cape Cod 

 grounds were highly significant in all years ex- 

 cept 1975, and differences due to tonnage class 

 were highly significant for all years. The interac- 

 tion was highly significant in only 35% of the 

 years (Table 4). 



Differences in CPUE by depth zone were gener- 

 ally not significant. Depth main effects yielded 



Table 4. — Frequency with which highly significant (P < 0.01) re- 

 sults were obtained from analysis of vanance (ANOVA) tests of 

 yellowtail flounder annual CPUE data. (Total number of years 

 tested = 20.) N/A = Not applicable (tests not performed). 



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