Size of the South American Sardine (Sardinops sagax) Population in the Northern Part of the Peru Upwelling Ecosystem after Collapse of Anchoveta (Engraulis ringens) Stocks

New estimates of sardine (Sardinops sagax) biomass suggest that a change in state of the Peruvian upwelling ecosystem, previously thought to be from one of anchoveta (Engraulis ringens) dominance to one of equal abundances of sardine and anchoveta, has been a clear switch in dominance from anchoveta to sardine. The sardine stock inhabits the northern part of the Peru upwelling system and extends its distribution into waters off Ecuador. Virtual population analyses show the population to have been considerably larger than was previously thought, with a biomass in 1982 estimated at between 15 and 18 million tonnes. The anchoveta collapse appears to have allowed a large bloom in sardine abundance. Sardine stock size has declined in recent years, concurrently with estimated mortalities in excess of F0.1 and declining recruitment.