POLACHECK: YELLOWFIN TUNA CATCH RATES 

 35- 



30 



25 H 



>- 

 < 

 Q 



q: 

 111 



20 



15 



10 



5- 



II 



I I I I I J I I I I I M ! T 1 I I I I I I ITTTTTTJT1 I I T 1 I • I I I J 1 11 1 I I I I I I r I rl I T I T 1 1 T I T I I T T 1 T T 1 I ri I I T I 1 1 I I I T 1 I T T TTTTTTTTTTI 



1979 1980 1981 1982 1983 1984 1985 1986 



Figure 2.— Estimates of the monthly catch rates of yellowfin tuna for Japanese purse seiners (metric 

 tons per day of effort) in the western Pacific. Error bars represent the estimates of one standard 

 error. 



Table 1 .—Comparison of annual estimates of the overall average catch rate of yellowfin tuna (metric 

 tons per day) by Japanese purse seiners in the western Pacific based on various areal and temporal 

 stratifications of the data. Values in parentheses are estimates of standard error and n is the number 

 of strata contained within each estimate. Stratum with less than five days of effort are not included. 



127 



