FISHERY BULLETIN: VOL. 72, NO. 2 



Lfl 



z 

 a 



u 

 1—1 



Z 



a 



25.00 



SS-50 



30-00 



17.50 



15-00 



lS-50 



10-00 



7.50 



5-00 



2.S0 



0-00 



SARDINE. ANCHOVY, AND HAKE B I DMA55- -CENTRAL AREA 



1980 1970 1960 1950 ISaO 1930 1930 1910 1900 1B90 1B90 1970 igGO 1B50 18-10 1830 1830 1910 1900 1790 



35.00 ^ 

 23.50 

 30-00 

 17-50 

 15-00 

 13-50 

 10-00 , 

 7-50 



SARDINE. ANCHOVY, AND HAf<,E BIDMAS5- -SOUTHERN AREA 



1980 1970 1960 1950 1940 1930 1930 1910 1900 1890 1880 1970 IGEO 1B5C IS-JO 1830 1830 1810 1800 1790 



Figure 9. — Combined biomass estimate for the Pacific sardine, the northern anchovy, and the Pacific hake in Alta California and 

 southern Baja California waters, 1810 to 1969. The biomass estimates are derived directly from the information in Tables 3, 4, and 5. In 

 the case of the hake the average population level for the years 1950-1965 was assumed to be 0.9 x IC^ metric tons (P.E. Smith, pers. 

 comm.). One half of this population has been assigned to the central region; the other half has been assigned to the southern region. The 

 actual relations used in the biomass calculation are as follows: 



Sardine — Santa Barbara (central population) and Soledad (southern population): sinceN^ = 2.27S^2 + 2.15 andB/= 0.38N; -0.40 

 (Spearman rank-correlation coefficient is 0.97, n = 6; see also Sette, 1969); then Bt = 0.85S^2 + 0.40 



Anchovy— Santa Barbara: Bt = 0.36S^ - 0.64; and Soledad: Bt = 0.08S^ -I- 0.29 



Hake— Santa Barbara and Soledad: Bt = 0.08S( 

 where N is number of 2-yr olds, B is annual spawning biomass, S is scale deposition rate, and subscript t refers to year. The mean 

 spawning biomass estimates for the sardine, anchovy, and hake are 3.5, 3.0, and 2.0 million tons for the central population and 0.7, 1.0, 

 and 0.5 for the southern area. 



importance of the central region would also likely 

 extend to the north through the seasonal migra- 

 tion of these fish. 



The projected mean biomass level for the three 

 main species off California over the past 30 years 

 is roughly 2 million metric tons and over the past 

 150 yr is 8 million metric tons. Thus the recent rise 

 of the anchovy population may simply be a return 

 to reasonably productive conditions. It is ironic 



that most of man's experience in the waters off the 

 Californias appears to be associated with low 

 pelagic-fish productivity. Conceding a significant 

 effect of the fishery on the Pacific sardine does not 

 mitigate the synchronous low population levels of 

 the anchovy and the hake. As a matter of perspec- 

 tive, it should be emphasized that most of the 

 understanding regarding the California Current 

 system and pelagic fish, particularly that from 



270 



