Paris Convention. Annual report on direct and riverine inputs to Norwegian coastal waters during the year 1996. A: Principles, results and discussion B: Datareport

Abstract

Riverine inputs of nutrients, selected heavy metals and persistent organic pollutants to Norwegian coastal waters from 10 main and 145 tributary rivers have been monitored during 1996. In addition, the inputs from rivers not monitored as well as direct discharges to marine waters along the coast from Sweden to Russia have been estimated. According to the results, total annual nutrient load to coastal waters from landbased sources, is approximately 3400 tonnes of phosphorus and 90.000 tonnes of nitrogen. About 34 per cent of the phosphorus and 54 per cent of the nitrogen are inputs from the monitored rivers and tributaries. Most inputs of heavy metals are low, especially the riverine inputs of Cd, Pb and Hg. A few values of Cd and Pb are below the detection limits of the specific analysis, and about 65% of the Hg-analyses except for the "Skagerrak-rivers", where more than 75% of the Hg-values are above the detection limit. Most values of the different congeners of PCB are below the detection limit. The pesticide lindane is detected in most analyses in small amounts. Total load of this compound is estimatd to about 76 kg. The largest yields from heavy metals comprise copper and zine, with input estimates of 289 and 1002 tonnes, respectively. Retention on the fjords is not included in the above mentioned values, which in several cases would reduce the actual load to open marine waters considerably.