Fish farming causes emissions of organic matter and nutrients. These emissions will have a negative impact on the environment if the production rate is too high in relation to the capacity in a particular locality.
According to the authorities, emissions from the aquaculture industry only account for two percent of the naturally occurring nutrients in the sea.
The application process to run a fish farm includes completing a survey of the locality’s environmental conditions. If the application is successful, an emissions permit is granted.
Fish farming companies are obliged to carry out regular checks to confirm that the environmental conditions are satisfactory and in accordance with Norwegian Standard NS 9410. The checks include inspections of the seabed and animals living in the sediments. The results of the inspections are used to evaluate how the aquaculture site affects the seabed. One inspection maps the facility's production zone (MOM B), another investigates the impact of the transition zone (MOM C). The production rate is adjusted according to the results, to make sure that the capacity of each site is not exceeded.
The Directorate of fisheries monitors the results of the environmental studies, and takes action if the conditions are unacceptable. In recent years, studies show that the environmental conditions generally have improved. In 2014, 94 percent of the aquaculture sites were shown to have good or very good environmental conditions in the production zone. The environmental status of the transition zone was rated good or very good in 93 percent of the sites.
The Directorate of fisheries on environmental conditions (in Norwegian only): http://www.fiskeridir.no/Akvakultur/Nyheter/2015/0215/Gode-miljoeforhold-ved-oppdrettsanleggene