Modeling transport and survival of anchoveta eggs and yolk–sac larvae in the coastal zone off central-southern Chile: Assessing spatial and temporal spawning parameters

Abstract

A hydrodynamic model was coupled to an individual-based model (IBM) initialized with conditions observed during 2004 to examine the influence of spatial and temporal spawning parameters on transport and survival of Engraulis ringens in central-southern Chile. Processes modeled were transport, growth, and mortality of the early stages. The results showed that spatial and temporal variations in spawning modulated the survival of anchoveta eggs and yolk–sac larvae. The resultant transport of the early stages had an important south–north direction. In terms of connectivity, the greatest transfer of eggs and larvae to the pre-recruitment zone came from four spawning zones. Retention occurred in all spawning zones and was strongest in the Gulf of Arauco and at Lebu– Corral. Mortality due to temperature and advective losses was more intense at higher latitudes ( Lebu– Corral). Observed and simulated distributions of eggs and larvae were compared, and the differences are discussed herein. A conceptual model is proposed, and we discuss the relevance of IBMs as useful tools with which to assess spawning zones for purposes of management.