The drainage area of the Gulf of Bothnia is 481,000 km2, of which about 2/3 is located in Sweden and 1/3 in Finland. About half of the drainage area is forest and only 4% is agricultural land.
The total annual load of nitrogen on the Gulf of Bothnia is 175,000 tonnes, of which 55,000 tonnes comes from Sweden, 39,000 tonnes from Finland, 77,000 tonnes with atmospheric deposition on the sea surface, and 4,000 tonnes from nitrogen fixation. The Swedish pulp and paper industry discharged 2,300 tonnes of nitrogen into the Gulf of Bothnia in 1991, corresponding to 1% of the total nitrogen load.
The annual load of phosphorus on the Gulf of Bothnia is 7,900 tonnes, of which 2,600 tonnes comes from Sweden, 3,700 tonnes from Finland and 1,600 tonnes with atmospheric deposition. Discharge from Swedish pulp and paper industry contributed in 1991 with 270 tonnes of phosphorus, corresponding to 3% of the total phosphorus load.
The annual load of metals from Sweden, Finland and the atmosphere has been estimated at 3,200 tonnes of zinc, 14 tonnes of cadmium, 790 tonnes of copper and 300 tonnes of lead. The Swedish pulp and paper industry is assumed to be responsible for 2% of the zinc load, 4% of the cadmium load, 0.6% of the copper load and 0.6% of the lead load.
The objective of this paper is to inform about nutrient and metal sources, located in Sweden and Finland, and to discuss where pollution abatement ought to be initiated. The loads of nitrogen, phosphorus and metals from the Swedish pulp and paper industry are not negligible in comparison with other minor anthropogenic sources, but when compared, e.g. with the atmospheric deposition directly on the sea surface, the contribution is small. An integrated national and international strategy, with clearly defined priorities and responsibilities, is urgently needed. Such an approach is only possible if an understanding of ecological and economical processes is used to implement a policy that will lead to a sustainable society and development.