Model for stock-recruitment dynamics of the Peruvian anchoveta ( Eugraulis ringens) off Peru

Abstract

This paper was aimed at re-examining the validity of the results from Cahuin et al. (Estuar. Coast. Shelf Sci. 84, 2009) and identifying a model to describe the stock-recruitment relationship of the Peruvian anchoveta (Eugraulis ringens). Re-gression analysis was used to determine if den-sity-dependent effects were present. The analy-sis did not show the existence of any density-dependent effects. It is important to use envi-ronmental factors and take observational and process errors into account when attempting to identify density-dependent effects in fish popu-lations. Sea surface temperature (SST) and Sou-thern Oscillation Index (SOI) were used as in-dependent variables to fit the recruitment dy-namics of the anchoveta. Both SST and SOI were found to be significantly important para-meters in structuring anchoveta dynamics ac-cording to Akaike Information Criterion (AIC) and R 2 values. The results of this study do not correlate with the findings of Cahuin et al., (2009), where density-dependent effects and the presence of regimes were detected. In conclusion, the re-cruitment R t is essentially determined in propor-tion to spawning stock biomass S t , and then en-vironmental factors in year t further change the recruitments. This mechanism is completely same with that for Japanese sardine proposed by Sa-kuramoto (The Open Fish. Sci. 5, 2012).