SOUTAR ;ind ISAACS: ABUNDANCE OF PFLAGIC FISH 



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PACIFIC SARDINE. SDLEDAD BASIN 



1^0 1970 laeo 1950 1940 1930 19B0 1910 1900 1B30 IBBO 1870 IBEO 1B50 1B.40 1830 18S0 1810 1800 1790 1780 1770 



NORTHERN ANCHOVY, SOLEDAD BASIN 



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1980 1970 19E0 1950 19-SO 1930 1920 1910 190O 1B90 IBBO 870 1860 1850 18->0 1830 IBeO IBIO IBOO 1790 17B0 



PACIFIC HAK.E. SOLEDAD BASIN 



19B0 1970 1360 1^0 1900 1330 19SO 1310 1900 1B90 1880 1B70 1860 1B50 IBAO 1830 1880 IfllO 1800 1790 1780 



Figure 5b- — Histogram plot of the scale deposition rate of the Pacific sardine, the northern anchovy, and the Pacific hake in sediment of 



the Soledad Basin from about 1780 to 1969. 



significant pattern of similarity in scale deposi- 

 tion (Table 8). The recorded increase in the an- 

 chovy population, while substantially above re- 

 cent historical levels, when compared to the in- 

 ferred population reached in most of the 19th and 

 the early part of the 20th centuries, appears mod- 

 erate. Furthermore, in contrast to the sardine, the 

 population of the anchovy has been of comparable 

 density in the waters of the Californias over the 

 past two centuries. This then supports contempor- 

 ary observations that the northern anchovy is re- 

 gionally adapted and is capable of successful popu- 

 lation responses covering at least the southern 

 half of the California Current. 



The inferred distribution of the Pacific hake. 



although made tenuous by the lack of clearly sup- 

 portive population information, is, in the case of 

 Santa Barbara Basin, strongly suggestive of the 

 anchovy with an indication of a recent increase 

 from low levels between 1920 and 1965 and with 

 substantially higher levels before 1920 (Table 8, 

 Figure 5). The inferred hake population in the 

 water near Soledad Basin corresponds with the 

 levels inferred for Santa Barbara back to the 

 1930's and in this regard is consistent with recent 

 observations of essentially equal larval abun- 

 dance in both areas. However, levels of inferred 

 population before 1930 at Santa Barbara are con- 

 siderably above those of Soledad, the latter show- 

 ing a consistent level over the past 200 years. 



265 



