Paris Convention. Annual report on direct and riverine inputs to Norwegian coastal waters during the year 1990. Report a: Principles, results and discussion

Abstract

Riverine inputs to Norwegian coastal water from 10 main and 145 tributary rivers have been monitored during 1990. The loading from rivers not monitored as well as direct discharges to marine waters along the coast fromSweden to Soviet Union have been estimated. According to the results, total annual nutrient load to coastal waters from landbased sources, is approximately 3.990 tons of phosphorus and 101.000 tons of nitrogen. About 50 % of the phosphorus and 60 % of the nitrogen are inputs from the monitored rivers and tributaties. Discharges of heavy metals and micropollutants are also included in the investigation. Most inputs of thesesubstances are low, especially the riverine inputs of Cd, Pb and Hg. Most values of these substances are below the detection limits of the specific analysis, which also is the case for the different congeners of PCBs. The herbicide lindane is detected in most analyses in small amounts. Total load of this compound is estimated to about 530 kg. The largest yields from heavymetals comprise opper and zinc, with input estimates of 630 and 1.670 tons, respectively. Retention in the fjords is not included in the above mentionedvalues, which in several cases would reduce the actual load to open marine waters considerably.