Ambitious nutrient reduction targets have been set for the Gippsland Lakes, Victoria but at what cost to productive agriculture? An interdisciplinary approach is addressing this question for the Moe River catchment, a dairy-dominated catchment that is a major source of pollutants to the Gippsland Lakes. Off-farm nitrogen exports are being estimated by biophysical modellers, and economists are quantifying the impact of farming systems and agricultural practices on farm profitability. This information is assembled to form the interim profit-pollution frontier for nitrogen reported in this paper, and to calculate abatement costs. Phosphorus and sediment exports will be considered in future work. This information is intended for use in a landscape-optimisation model that highlights how land uses can best be spatially allocated in the catchment to meet end-of-valley pollution targets at least cost.