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More than half of the fish at a Scottish salmon farm has been lost due to severe plankton.

Wester Ross Fisheries confirmed that 52.8% of its salmon at one site in Ardessie Farm in Little Loch Broom was wiped out in August.

Managing director Gilpin Bradley said the "catastrophic event" was "soul destroying for all our farmers".

He said rising sea temperatures led to reduced oxygen and more plankton which caused irreparable damage to the gills.

"This has been a catastrophic event for Wester Ross, in over 40 years of salmon farming," Mr Bradley said. "Our dedicated farmers have never had to manage such severe mortality in a very short period of time."

'Catastrophic mortality rates'

He added: "The seawater temperatures reached their summer peak causing catastrophic mortality rates of 52.8% at Ardessie Farm Site A and 41.9% at the Ardessie Farm Site B."

"This event was soul-destroying for all our farmers and staff who had been caring of these salmon for over 10 months at the time of the event.

"Fortunately, the remaining salmon have now been fully recovered and are growing well."

He said 2018 was a record year for seawater temperatures, causing more plankton issues and reduced oxygen levels at sea.

"Increasing seawater temperatures during summer months due to global warming will continue to be a major challenge for all sustainable seafood farmers around the world," he added.