ABSTRACT
Cost-effectiveness can be defined as obtaining one or several production targets at minimum cost. This chapter discusses the concept of marginal costs in the context of nutrient reductions to the Baltic Sea and presents the calculated marginal cost of measures involving the sources listed in the nutrient load table. It also presents the relationship between possible nutrient reduction targets and associated minimum costs for their achievement. Nutrient sinks can be created by constructing wetlands downstream in the drainage basin, close to the coastal water. Currently, the impacts on the ratio of nitrogen and phosphorous in marine waters to changes in the nutrient loads are unclear. Therefore, minimum costs are calculated for three different scenarios: reductions in nitrogen only, phosphorus only, or both nitrogen and phosphorus. The agricultural sector contributes mainly by reductions in nitrogen fertilizers, the cultivation of cover crops, and changed practices for manure treatment.
