Linking stage-resolved population models with field observations: an integrated approach on population dynamics of Pseudocalanus elongatus in the German Bight.
The population dynamics of Pseudocalanus elongatus have been investigated within
the framework of the GLOBEC-Germany project to gain a better understanding
of its life cycle and population dynamics and to estimate secondary production in
the North Sea. During an intensive field study in the German Bight between
February and October 2004, experiments on reproduction were performed and
data on length of copepodids and abundance were collected to characterize the
population in the southern North Sea. This data set was used to update the literature-
based parameterization of a population model for P. elongatus to investigate the
population dynamics, life history and production in the German Bight. The
ability of data to improve population models is also discussed. Pseudocalanus elongatus
was found to be a major contributor to carbon uptake contributing about onethird
of copepod production. Though the spatial variability in field observations
was not reflected by the model, the simulation matched data within one order of
magnitude at most stations. The high-resolution field observations and experiments
mainly improved the parameterization of the reproductive parameters.
Mortality is found to be a critical parameter due to its influence on population
size. Using constant rates, though based on observation-derived estimates, seems
not to capture realistic variability. Our study confirms the need for experimental
and field data to build a robust parameterization for concentration-based
population models