FISHERY BULLETIN: VOL. 72. NO. 1 



A 



WASHINGTON 

 1970 

 N  650 



llTTk 



WASHINGTON OREGON COMBINED 

 1970 



Jl 



Ilk, 



WASHINGTON- 

 VANCOUVER ISLAND 



1971 

 N • 619 



,^.^rfltb^ 



WASHINGTON-VANCOUVER ISLAND 

 OREGON COMBINED 

 1971 



^ 



■^^ni}h 



ITO I9C ZIO 230 250 270 290 310 220 240 260 280 300 320 340 160 200 220 240 260 280 300 320 340 



IQ KNOB LENGTH (mm) 





CALIfOflNIA 1969 

 N. 823 



Mll^l^ 



140 150 (70 190 210 2)0 !50 270 290 

 KNCB LENGTH (mn) 



Figure 2. — Length frequency distributions of eastern Pacific saury captured off 

 the Pacific coast of North America during August-September 1970-71. 



Figure 2 also shows length-frequency dis- 

 tributions for combined Washington-Oregon 

 samples in 1970 and Washington-Vancouver 

 Island samples in 1971. A bimodal distribution 

 is not apparent in 1970 but is distinct in 1971. 

 Little variation in modes is noted between years. 



Age frequency was determined from the 13 

 saury schools samjjled off the Oregon-Washing- 

 ton-Vancouver Island coasts during 1970-71. 

 Figure 3 histograms indicate the percentage of 

 age groups by area, year, and areas combined 

 within year. 



Variations in age comi)osition by latitude 

 followed the expected trend established by 

 size composition. Oregon fish were predomi- 

 nantly 1- and 2-year-olds while Washington- 

 Vancouver Island fish were predominantly 2-, 

 3-, 4-, and 5-year-olds. Age composition of 

 Oregon samples indicated little variation be- 

 tween 1970 and 1971 with age groups 1 and 

 2 representing 89% of the 1970 fish and 92% of 

 the 1971 fish. In contrast, Washington fish 

 showed considerable variation between years. 

 In 1970, 93% of the fish were 2- and 3-year-olds 

 while 54% were 4-year-olds in 1971. Sampling 

 deficiencies probably account for the decline in 

 the I'elative abundance of the 1968 year class 

 between 1970 (2-year-old fish) and 1971 (3-year- 

 olds). Fish aged as 6-year-olds were represented 

 in 1970 and 1971 Washington samples, but it 

 appears few fish survive beyond the age of 5. 



Fish of the spring-born scale type consistently 

 dominated all schools sampled (Figure 4) and 

 also dominated most age groups. The greatest 

 variation occurred at Oregon latitudes where 

 fish of the autumn-born scale type comprised 

 27% of the 1970 samples and 12% in 1971. 

 Washington sami)les were comprised of 21% 

 autumn-born type in 1970 and 22% in 1971. 



Sex Ratio and Maturity 



The sex ratio was examined by age group for 

 variation between area, year, and scale type. 



Area differences in age composition and 

 difficulties in determining sex of young fish 

 hampered some comparisons; however, numbers 

 of males and females were about equal through 

 age 3 with females becoming predominant at 

 age 4 and beyond. For more meaningful anal- 

 ysis, ages 1-3 and 4-6 were pooled for each area- 

 year category. The sex ratio of saury of autumn- 

 and spring-born scale types were next examined 

 and found so similar that statistical treatment 

 was unnecessary. Sex ratios of area-year-age 

 group categories are presented in Table 2. While 

 the sex ratio was age-dependent, sex composi- 

 tion differences in 1-3 year-olds of Washington 

 vs Oregon catches in both 1970 and 1971 and 

 4-6 year-olds of Washington vs Oregon catches 

 in 1971 were nonsignificant (0.05 level). 



Size and age at first maturity could not be 



124 



