Discharges of dissolved nitrogen and phosphorus and organic material from the aquaculture sector constitute a minor environmental problem in Norway. A long coastline and use of aquaculture siteswith good water quality and good water exchange are contributory factors. Fish farms are located in either exposed areas or relatively deep fjords with a high carrying capacity for discharged nutrient salts and organic material.
Discharge permit with strict limits
Nutrient salts such as nitrogen and phosphorus and organic material from fish farms rarely have a negative local impact. However, in certain areas with a high density of fish farms, regional impacts cannot be excluded. All fish farms in Norway have a discharge permit issued by the environmental authorities. These permits are issued on a sound scientific basis, with strict limits imposed on the quantities of nutrient salts and organic material that may be discharged.
Required to perform regular monitoring
Before approval of a new aquaculture site or expansion of an existing site can be granted, benthic monitoring along with hydrographical and topographical surveys is mandatory. During operation, farmers are required to perform regular monitoring at a frequency determined by the size of the site (i.e. the volume of fish permitted at the site) and the results from previous monitoring.