|Dynamic interactions between the lower trophic levels of the marine food web in relation to the physical environment during the Fladen Ground experiment|
Radach, G. (1982). Dynamic interactions between the lower trophic levels of the marine food web in relation to the physical environment during the Fladen Ground experiment. Neth. J. Sea Res. 16: 231-246
In: Netherlands Journal of Sea Research. Netherlands Institute for Sea Research (NIOZ): Groningen; Den Burg. ISSN 0077-7579, more
Problems of modelling the ecosystem of the northern North Sea are discussed in relation to available measurements furing the Fladen Ground Experiment (FLEX '76) which covered the spring plankton bloom from March to June 1976. The conditions generally necessary for making up balances of the local dynamics are investigated considering physical processes like advection and the formation of the seasonal thermocline. Time intervals are sorted out, for which modelling of local dynamics seems promising. Validational problems are exemplified by presenting the results of a simulation of phytoplankton dynamics over nearly one month. It shows that validation can only be succesful if, in addition to standing stocks and concentrations, also flux measurements or estimates have been performed. Independent estimates for primary production and grazing are presented on different theoretical grounds and on the measured data. It is shown that the inacuuracies inherently involved in such estimates strongly limit the validation of the simulation model. The validation, taking several sets of data combinations into account, only provides ranges for the flows of matter accumulated during the time range of the simulation. Rates of daily rates of transport are given for all processes involved in the simulation model, including sinking, turbulent diffusion, primary production, respiration, mortality and grazing during diatom blooms.