The application of a M2 nonlinear numerical tidal model to the shelf seas of central New Zealand (~38.500 km2 area) is described. It has provided a preliminary assessment of tidal and residual currents, bottom stress, energy dissipation, and the stratification index. The existence of a permanent, tidally driven mesoscale eddy (~75 km diameter) is predicted nort of D'Urville Island. Large spatial gradients in bottom stress qualitatively agree with many features of the surficial sediment distribution. A comparison of all available bulk stratification data with the h/u3 stratification index clearly demonstrates the dominance of tidal versus wind mixing over the control of summer stratification. A potential application of the model to fisheries science is suggested through a comparison of the stratification index contour map and some observations of squid fishing vessel locations.