<i>Calanoides acutus</i> in Gerlache Strait, Antarctica II. Solving an inverse problem in population dynamics

Abstract

A population dynamics model of the overwintering Southern Ocean copepod, <i>Calanoides acutus</i>, was constructed based on field observations of abundance in the Gerlache Strait during November 1989. We used an analytical solution to solve an inverse problem to determine rates of stage-specific mortality and development as the population emerged from overwintering diapause. Model predictions of mortality rates for CIV, CV and CVI copepodites were 0.068, 0 and 0.131 day−1, respectively. Best fit solutions of the model predict that late-stage copepodites emerge from diapause by “pulse moulting;” overwintering copepodites appear to emerge from diapause en masse in a relatively brief period prior to the annual spring bloom, rather than moulting at the comparatively slow rates observed in summer. We suggest that the modelling approach we used may have application to many species of copepods whose populations overwriter.