Life history traits and spatiotemporal distributional patterns of copepod populations in the Gulf of Maine-Georges Bank region

摘要

Life history traits play a significant role in determining the spatiotemporal distributional patterns of marine zooplankton, but biological-physical mechanisms controlling the population dynamics need to be further examined. In the present study, we used a coupled biological-physical model to examine the processes controlling the observed distributional patterns of 3 representative copepod populations in the Gulf of Maine-Georges Bank region including Pseudocalanus spp., Cen-tropages typicus and C. hamatus. The model reveals that the shorter generation time of Pseudocalanus spp. at cold temperatures, together with their egg-carrying strategy, allows an earlier population development compared to Centropages spp. The model further reveals that predation mortality plays an important role in the decline of Pseudocalanus spp. in the warm season, and that the resting egg strategy is crucial for the persistence of the C. hamatus population in the Gulf of Maine-Georges Bank region. Analyses of observational data and model results suggest that temperature- and food-dependent egg production and development rates, temporally and spatially varying mortality rates and physical transport are important contributors to the formation of characteristic distributional patterns for the copepod populations in the system.