Salmon farming is a profitable industry that helps to feed millions, but it is not without consequences.
A new report titled 'Dead Loss' by the organisation Just Economics has revealed that the cost of salmon farming pollution, fighting salmon parasites and mortality rates amounted to around $50bn globally from 2013 to 2019.
Dead Loss, which was written in association with the Changing Markets Foundation, also revealed that the number of wild fish used in salmon farms is also a growing concern, as well as the spread of sea-lice, which essentially eat salmon from the inside out.
Nearly one fifth of the world’s annual wild fish catch, amounting to about 18 million tonnes a year, is used to make fishmeal and fish oil, of which around 70 per cent goes to fish farms.
The report added that this is causing issues for fishers in developing countries, who are seeing their stocks depleted in order to feed western consumption of farmed fish.
Natasha Hurley, campaigns manager at the Changing Markets Foundation, told The Guardian: 'Moving away from using wild caught fish in food would make salmon farming more sustainable, as it is having a huge impact on wild fish.'
She added that she felt that consumers were often unaware of what they were buying, as fish is poorly labelled in supermarkets and its farmed origin is often not clear.
Instead, she said that governments should tighten their rules on licensing fish farms, to enforce lower stocking density on farms, and improve labelling.
In the context of Ireland, salmon farming began nearly three decades ago in Ireland.
She said that another alternative salmon farmers could use is oil sourced from algae, which is a good source of omega 3.
This echoes the reports findings that algae could be fed to wild fish, but few farmers are reportedly doing so.
Official figures show that while global aquaculture production has grown by 164 per cent since 2000, output in Ireland has fallen by 24 per cent in the same period.
Salmon Watch Ireland director John Murphy previously explained in 2019 that the number of adult fish returning to our coast has dropped from 2 million in the 1970s to 250,000.
He added that it is for this reason that the extinction of the Irish salmon 'is a possibility.'
Since then, Ireland has gone from 5 per cent of European aquaculture production 20 years ago to less than 2.5 per cent today.
In related news, it was revealed last month that a Galway fish farm was ordered to stop allowing diseased salmon to bathe in lake water by the High Court.