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 facilities with good water quality 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.
The regulations under revision
The regulations applicable to discharges from aquaculture sites are currently under revision. The purpose is to introduce more stringent requirements in terms of local benthic monitoring. Also, if the revised regulations are implemented, rather than monitoring the discharges from each facility individually, the total discharge in a given area will be taken into consideration. The revision is an initiative that is in line with the government’s strategy for an environmentally sustainable Norwegian aquaculture industry, presented in April 2009. Both of these revision processes will soon be submitted for public hearing by the environmental protection authorities.