Treatment for lice ‘led to 175,000 fish deaths’

SCOTTISH fish farms have accidentally killed thousands of salmon by overheating them while treating them for lice and disease, according to government documents.

The internal memos say that Marine Harvest killed more than 175,000 salmon across Scotland.

Campaigners accuse the fish farm company of inhumane treatment of the fish.

In the worst loss – in July and August at Loch Greshornish, Skye – 95,400 fish were said to have been killed by a thermolicer device. This is designed to get rid of sea lice on salmon by immersing them in water much warmer than they are used to.

A September 12 memo from officials to Rural Economy Minister Fergus Ewing said the ‘sudden temperature change’ killed 95 per cent of the lice but also caused ‘significant mortalities’ among the salmon. Another 20,000 fish were said to have died at Loch Greshornish when chemicals were used to combat sea lice. The memos were obtained in a freedom of information request by Don Staniford, director of Global Alliance Against Industrial Agriculture.

He said: ‘That Marine Harvest is desperate enough to resort to a decidedly dodgy thermolicer shows how deep-rooted the industry’s disease problems are.’

Chief executive of Compassion in World Farming Philip Lymbery said: ‘Killing fish by overheating, whether accidental or not, is simply inhumane.’

Marine Harvest said the fish lost in the ‘unfortunate’ thermolicer incident were weakened by gill disease. Manager Steve Bracken said: ‘We regret any loss of fish and are always mindful of the welfare of the fish and aim to continuously improve our methods.’