The pursuit of profits by salmon producers globally is creating significant environmental and social damage, according to a new report.
New analysis from Just Economics into fish farming puts cumulative costs since 2013 at almost £36 billion (50 billion dollars).
More than half of these are falling to producers with the rest being passed on to society in the top four salmon-producing countries.
Eilis Lawlor, director of Just Economics, said: “There is a growing demand from consumers to source fish from producers that care for the environment, protect coastal communities and prioritise fish welfare.
“However, our analysis shows that salmon farming is incurring significant economic, social and environmental costs that are not currently accounted for in company reporting.
“Investors should factor in the long-term risks facing salmon aquaculture and governments should implement robust regulation to ensure that companies rapidly switch to more sustainable farming practices.”
Norway, Scotland, Canada and Chile account for 96% of farmed salmon across the world.
The Dead Loss report, commissioned by the Changing Markets Foundation, analyses the impacts of the industry in these four countries.
It identifies poor fish husbandry, parasites and pollution as causing hundreds of millions of fish mortalities before they are ready for slaughter.
This accounts for the highest proportion of the costs.
A total of 10 companies account for 50% of global salmon production.
The report highlights the short-term pursuit of profits by these producers as resulting in the deaths of 100 million salmon since 2010.
A Scottish Salmon Producers Organisation spokesman said: “Farmed salmon has a great environmental story to tell. Salmon has the lowest carbon footprint of any main livestock protein, it is a nutritious and healthy food and, as the UN and other international experts have acknowledged, aquaculture provides one of the best solutions to feed the world’s burgeoning population in the years to come.
“It is a shame that the authors have chosen to ignore these benefits when compiling this report.”
A spokesman for the International Salmon Farmers Association said: “Unfortunately, a review of the paper makes it clear that this is simply activism masquerading as academic analysis.
“The paper is not supported by facts, includes no discussions with independent experts, and lacks the critical context required to offer useful insights.”