MATHEMATICAL-MODEL OF BACTERIAL-CONTAMINATION OF THE MORLAIX ESTUARY (FRANCE)

By a modelling procedure, knowledge concerning bacterial transport and disappearance can be attained to provide useful management information for minimizing faecal pollution in shellfishing areas such as Morlaix Bay. A set of two numerical models was built to simulate currents, water fluxes, transit times, trajectories, dispersion and bacterial decay. The models were tuned and fed by survival trials carried out in the field with Escherichia coli strains. Die-off rates ranged from 2 h to 1 week. Model results compared well with in situ measurements and show that, in all circumstances, physical dilution processes are much more efficient than mortality in this estuary. The last simulations provided suggestions for improving water quality in the study area. © 1990.