A Fine Kettle of Fish

A new scientific study claims that salmon farming operations have reduced wild salmon populations by up to 70 percent in several areas around the world, including parts of Canada, Scotland and Ireland.

The reduced survival of wild populations is believed to be due to the fact that the juvenile wild salmon migrate past salmon farms on their way to the ocean.

‘This report is the first global assessment of the impacts of fish farms on wild salmon populations, and the results are startling,’ said Jennifer Ford, Canadian biologist and lead author of the study. ‘The findings from our analyses varied in different regions, but by combining them, we see that there is a negative impact on wild salmon that is highly significant.’

‘Our estimates are that they [fish farms] reduced the survival of wild populations by more than half,’ said Ford. ‘Less than half of the juvenile salmon from those populations that would have survived to come back and reproduce actually come back because they’re killed by some mechanism that has to do with salmon farming.’

Previous studies have shown how breeding between farmed and wild salmon caused great damage to wild stocks, through passing diseases and parasites. However, this is the first survey to be undertaken to assess the importance of the impact at the population level and across the globe.

Trevor Swerdfager, director general of aquaculture management for the Canadian Federal Fisheries Department, said his department would be taking a close look at the new research but maintained that it has not yet seen any proof that salmon farms harm wild populations.

Swerdfager admitted that, while the causes behind stock declines were unresolved, there were many other factors that could be possibly linked to the problem, such as changes to ecosystems, fishing practices and climate change.

Source:
Canadian Press