For the hydrodynamic model we have also conducted Lagrangian (drogue) surveys with paired-released drogues downstream of commercial fish farms to study horizontal dispersion of water using dGPS locating equipment. Our data compares closely with literature values being reported for the first time recently and we are aware of the range of diffusivity that may occur with differing types of net pen structures.
The plankton submodel is a system of interlinked equations to characterize the dynamics of the planktonic community. It traces the cycling of carbon, nitrogen, and oxygen within each element of the array, both within the farm and the surrounding waters, and output from the model (Kiefer & Atkinson, 1984). Outputs consist of the time series at each element of the array of the concentrations of dissolved inorganic nitrogen, carbon dioxide, and oxygen, as well as the organic nitrogen and carbon in the phytoplankton and zooplankton. The model displays predator-prey oscillations that dampen with time, reaching a steady state. Typically it is hard to stimulate a bloom from operation of a single farm in most environments but large numbers of farms could do so.