Spatial dynamics of anchovy, sardine, and hake pre-recruit stages in the California Current

Three genera, Engraulis, Sardinops, and Merlucciu have coincident spawning and juvenile brood areas in most eastern and western boundary currents thro ughout the world, The CalCOFI survey program has amassed a 50-year data ser ies on location and timing of spawning and the resultant recruitment of anc hovy, sardine, and hake in the California Current region. Use of existing L efkovitch matrix population projection models for these three species allow s evaluation of the spatial and temporal scales that govern the biological and physical interactions. We present rate diagrams for hake and construct comparable diagrams for anchovy and sardine in a common, variable environme nt, Rate diagrams depict the relative importance of demographic (natality a nd mortality), growth. and kinematic (passive and active movement) processe s to a quantity of interest as a function of spatial and temporal scale. Re sults confirm that the scale of observations will have to be manipulated to expose the importance of any combination of processes for life history sta ges among these species. Field sampling systems have not yet responded adeq uately to mesoscale features (50 km) persisting over months.