Wild fish at risk from salmon farms

Increased numbers of sea lice in farmed salmon could affect wild fish too.

<> on October 27, 2014 in Selkirk, Scotland.

Infestations of sea lice, a tiny parasite usually less than 1.5cm long, are affecting salmon farms in both Norway and Scotland.

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Following a deadly algae bloom affecting the salmon farmed in Chile, there has been a 50 per cent increase in wholesale salmon prices, but it is more than just the price of fish that could be impacted. 

“There is a risk of passing wild fish picking up lice larvae from open net salmon farms,” said Scottish Wildlife Trust’s Rory Syme. “There is evidence that this affects both wild salmon and also sea trout.”

Research has shown that fish farms are a source of lice infestations in wild salmon as open net salmon farms allow the free movement of pathogens, such as the sea lice, between wild and farmed fish.

It is thought that conditions are ideal in the farms for infestations of sea lice to develop, due to the high densities of fish.

New measures are being put in place later this year in Scotland to try and prevent sea lice larvae from getting in or out of the sea cages.

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