FISHERY BULLETIN: VOL. 84, NO. 3 



12). For example, the total estimated kill for 1977 cept that values for the species or species grouping 



(Table 13) was obtained as a sum of estimates of the were substituted for the totals in (b) and (c) above, 



total for three strata as [(5,722)(2.95) + 175] + Similarly, I estimated the variance of the number 



[(1,128)(4.20) + 15] + [(252)(4.68) + 0]. Estimates of dolphins killed during any year by summing 



for each species or species grouping were obtained variance estimates for each stratum. The estimated 



in the same manner as estimates of the total, ex- variance of total kill for a stratum was computed 



Table 12.— Total number of dolphins killed (/c), number of dolphin sets (d), and number 

 of experimental-gear trips (n), by year within strata. These data were excluded from 

 all sample and population statistics. 



Table 13.— Estimates of dolphin mortality incidental to U.S. purse seiners, by species 

 grouping and year, with coefficients of variation in parentheses. 



'May include small number of Costa Rican spinner dolphins. 



2 Sum of estimated kills over species grouping not exactly equal to total estimated kill because 

 of rounding error. 



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