SMITH ET AL.: MORTALITY RATES OF SARDINE AND ANCHOVY EGGS OFF PERU 



LU 

 H 

 < 



tr 



>- 



o 



20 



40 



60 



BIOMASS 



Figure 3. — Mortality rates in percent per day of anchovy aggs as a function of 

 anchovy spawning biomass concentration in grams per square meter; closed tri- 

 angles, Peru in nearshore regions IMARll, IMAR21, IMAR31 (this paper); closed 

 squares, values for the entire spawning region off California from 1980 to 1985 

 (Stauffer and Picquelle 1981; Stauffer and Charter 1982; Picquelle and Hewitt 1983, 

 1984; Hewitt 1985; Bindman 1986); and, open circles, for the entire spawning region 

 off South Africa in 1985 and 1986 (Armstrong et. al. 1988). 



Table 6. — Anchovy egg mortality rate and adult spawning 

 biomass concentration in the Humboldt (Engraulis ringens). 

 California (E. mordax). and southern Benguela (E. capensis) 

 currents. 



CONCLUSION 



MacCall (1980) stated that only 10% of the 

 apparent control of northern anchovy recruit- 

 ment off California may be due to stock size, 

 with the vast majority of control arising from 

 means that are independent of stock size. Lasker 

 and MacCall (1983) concluded that the best 

 measures of the stock recruitment curve are not 

 sufficient domed for cannibalism to be a "major 

 regulatory mechanism". Also, it appears from 

 examination of the life stages of northern an- 

 chovy (Smith 1985, table 3) moderate reproduc- 

 tive failures could happen at the fecundity, em- 

 bryonic, larval, and juvenile prerecruit stages, 

 but a reproductive success of great proportions 

 would most likely arise at the embryonic and 

 larval stages. The size of the recruited year class 

 vdll accumulate the rates of early stages, and the 

 later the prerecruits are evaluated, the more 

 hkely the reproductive success will have been 

 established. Peterman et al. (1988) evaluated 

 only the first 20 days of Hfe. 



For 6 successive years (included in Peterman 

 et al. (1988)), the interannual coefficient of varia- 

 tion of the spawning biomass was 35% and the 

 interannual coefficient of variation of recruit- 



505 



