4.6 Concluding remarks
Together, the examples used to illustrate the controllability of
riverine loads of nutrients have drawn attention to the role of
long-term processes and hydrological pathways. Although it is often
easy to reduce very high concentrations and loads to more moderate
levels, it may take decades to achieve further reduction. In
addition, successful abatement of riverine nutrient pollution of the
Baltic Sea will probably require coordinated control of both
phosphorus and nitrogen emissions.
