A model for contaminant transport in Lunenburg Bay, Nova Scotia

A three-dimensional tidal non-linear barotropic model has been developed to examine the flushing characteristics of complex bays and inlets. The model has been applied to Lunenburg Bay with a fine grid to investigate the hydrodynamics as part of bivalve aquaculture feasibility programs. Observations have indicated the need for a highly nonlinear model: a jet-like outflow from coves into the bay and hydraulic control of the tide at a narrow constriction. These hydrodynamic features have special roles to play in the exchange of water masses between the bay, adjacent inlets and the open sea. Passive water quality variables are simulated by large numbers of Lagrangian drifters which are advected through the model domain by the tidal currents. Preliminary results show that bays and adjacent inlets cannot be considered in isolation from each other. Tidal exchange of water masses will affect the flushing of nutrients and contaminants and hence impact upon aquaculture and other activities.