An approach to the evaluation of the potential bio-productivity on the basis of mathematical modelling is discussed. To determine the potential productivity of biomass of this species that may be removed annually from the area of its habitation during an indefinitely long period. Over the long term, this catch of marine organisms will act on the natural substance circulation in the sea at increasing spatial scales. It is proposed to model the bioproduction processes by successive evaluation of biogenic substance resources which take part in these cisculations.