Introduction to the North Sea Project. Seasonal cycles and their spatial variability. The influence of horizontal circulation on the supply and distribution of tracers. Suspended particulate matter in the North Sea: field observations and model simulations. Dynamics of tidal mixing fronts in the North Sea. Circulation, hydrographic structure and mixing at tidal fronts: the view from Georges Bank. Hydrodynamics and sediment dynamics of North Sea and waves. Resuspension processes and seston dynamics, southern North Sea. Biological consequences of tidal mixing gradients in the North Sea. Modelling water column processes in the North Sea. Seasonal fluxes across the sediment-water interface, and processes within sediments. Trace gases and air-sea exchanges. The atmospheric distributions of trace metals, trace organics and nitrogen species over the North Sea. Processes influencing the fate of trace metals in the North Sea. Towards water quality models. The North Sea Project: an overview and the way forward. Index.