FISHERY BULLETIN: VOL. 84, NO. 3 



RESULTS 



Table 2.— Cumulative distributions of number of sampled U.S. 

 purse seine trips, by vessel capacity (tons) for the years 1973-78, 

 with relative frequencies (percents) in parentheses. 



Setting the breakpoint between small and large 

 vessel capacities at 600 tons (or lower) or at 1,200 

 tons would, in each case, create small and large 

 vessel categories with severely unbalanced sample 

 sizes (Table 2). The percent of sampled vessels with 

 capacity < 1,000 tons was more stable over years 

 than the percent of sampled vessels <800 tons, 

 especially from 1973 through 1976. Therefore, the 

 breakpoint between vessel categories was set at 

 1,000 tons. 



Because of data sparseness, particularly in the 

 North Outside and South areas (Table 3), I made 

 three multiway ANOVA tests restricted to subsets 

 of the whole data set: 1) two-way test of year and 

 vessel capacity, restricted to the North Inside area 

 and the second quarter, 2) three-way test of year, 

 quarter, and vessel capacity, restricted to the North 

 Inside area and the first two quarters during 1973 

 through 1976, and 3) four-way test, restricted to the 

 North Inside and North Outside areas, and the 



Table 3.— Number of dolphin sets made during sampled trips, by year, vessel capacity (tons), quarter of the year, and area. 



562 



