Norwegian fish farms polluting fjords with waste likened to ‘raw sewage of millions of people’ | Norway
Norwegian fish farms fill fjords and other coastal waters with nutrient pollution equivalent to the raw sewage of tens of millions of people every year. A report was found.
Norway is the world’s largest producer of farmed salmon, and the nutrients in the fish meal are released directly into coastal waters. Analysis by the Sunstone Institute found that Norwegian aquaculture will emit 75,000 tonnes of nitrogen, 13,000 tonnes of phosphorus and 360,000 tonnes of organic carbon in 2025.
The report found nutrients were equivalent to those found in the untreated sewage of 17.2 million people containing nitrogen, 20 million people containing phosphorus and 30 million people containing organic carbon, raising fears of a devastating algal bloom.
“Norway is a small country with only 5.5 million people, and the output of aquaculture pollution in terms of these three nutrients is three to five times greater than the population,” said Alexandra Pires Duro, data scientist at Sunstone and author of the report. “Feces, uneaten feed, urine; everything gets into the water.”
While farmed fish are raised for human consumption, they are fed nutrient-rich pellet feeds in open-mesh cages. Analysts calculated the amount of nutrient input remaining in the water using data from the national fisheries directorate and the veterinary institute.
The researchers found that feed consumption increased by 14.6% over a six-year period in line with the industry’s expansion, producing nutrient pollution equivalent to levels expected in the raw sewage of a country about the size of Australia in 2025. In a separate analysis, the report’s authors found that seasonal variation exacerbates the problem, with nutrient loads being highest in the summer months when ecosystems are least able to absorb the nutrient load.
Fish mud from nutrients can fertilize phytoplankton and lead to destructive algal blooms that deplete oxygen levels. Fjords are particularly vulnerable to such impacts because they are semi-enclosed bodies of water and allow greater nutrient accumulation. Oxygen levels are already falling due to global warming.
In Sognefjord, the country’s longest fjord, increased nutrient runoff (not just from fish farms) is blamed for nearly two-thirds of oxygen depletion. to work It was found last year, and warmer water was blamed for the other third.
Oxygen levels in deep waters in Hardangerfjord, Norway’s second-longest fjord, have also decreased, according to the country’s governor of Vestland.
In March, authorities rejected nine applications for fish farms in the fjord because of the increase in emissions they would cause. Tom Pedersen, an environmental consultant in the area who served as an expert reviewer on the Sunstone report, said the numbers in his analysis were not surprising and even “on the conservative side.”
“The biggest concern we’ve had over the last few years is that all this algae and plankton and whatever is dying, sinking to the ground and rotting, and that process uses up oxygen,” he said. “As a result, the oxygen level in the fjord is falling and falling.”
Norway’s fisheries ministry referred a request for comment to the fisheries directorate, which declined to comment.
Krister Hoaas, head of public affairs at the Norwegian Seafood Federation, the main industry association, said the volume of emissions reflects how much food is produced in Norway and the degree of self-sufficiency the country could have in an emergency. He said the industry is constantly working to make its environmental footprint as small as possible.
“It is important to distinguish between questions about current operations and questions about future growth,” he added. “The Institute of Marine Research is clear that a significant increase in production in certain fjord systems could increase the risk of local eutrophication, but current production is within nature’s carrying capacity. This provides a basis for stringent, site-specific management, but does not document that current operations are destroying fjords.”
