_L 



800- 



SPAWNING BIOMASS 

 LARVAL INDEX 



AERIAL INDEX 



PACIFIC 

 MACKEREL 



,l.,„4.a 



75 



in 



—I c 



o 



•oil 



o - 

 O 



co 

 CO 

 < - 



O - 

 25 m 



13 



< 

 CL - 

 CO 



1959 61 



63 65 67 

 YEAR 



69 



1.2 

 1.0 

 0.8 

 0.6 

 0.4 

 0.2 

 



c 



Figure 62. — Three independent estimates (spawning biomass, larval index, and aerial 

 index) of Pacifie mackerel abundance. 



A ACOUSTIC 

 / \ y INDEX 



l 



_L 



_L 



_L 



_L 



_L 



90 



80 



70 



48 



45 



40 



-35 



605 " 



30 "£ 



8 



o 

 > 





h. 



O 



o 



50 | " 



25 fg 



E 



o 



3 





C 



«M^ 



^-^ 





40>< " 



Q 



Z 



20 2 



Q 



Z 



30p ~ 



_l 



15 £ 



oo 



re 



8 



< 



_i 



o 





20< - 



10 



10 



- 5 



1963 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 



YEAR 



Figure 63.— Aerial, larval, and acoustic indices for the northern anchow. Aerial night index in arbitral*) units, acoustic index in schools per square nautical mile, and 



larval index in 10 1 - larvae. 



74 



