In August, Mowi Scotland achieved its lowest monthly mortality rate in over eight years and saw record high feeding and growth rates in the cooler coastal waters.
Mowi Scotland has recorded a significant reduction in salmon mortality rates during August 2024, with levels dropping to around one-third of those seen in recent years.
The decrease comes as El Niño conditions, which had caused a marine heatwave in the North Atlantic, begin to subside. This phenomenon, part of the El Niño Southern Oscillation (ENSO), led to warmer sea temperatures and increased mortality in previous years due to gill disease, according to the salmon producer.
“The decline of El Niño conditions, much cooler summer air temperatures, and higher rainfall have all benefited our salmon farming operations,” said Ben Hadfield, COO of Mowi’s operations in Scotland, Ireland, the Faroes, and Canada East.
“This weather, combined with our enhanced mitigation measures such as the use of freshwater treatments and bubble curtains, has proved effective.”
The company had anticipated some relief in 2024, following the challenges of the marine heatwave in 2022 and 2023. Mowi implemented several measures to address warmer seas, including using high-capacity freshwater treatments and bubble curtains to prevent jellyfish and algae from entering farming systems. “To see such a big fall in mortality rates is really encouraging because all our focus as salmon farmers is about caring for the fish,” Hadfield added.
Improved biological conditions see strong Q2 for Mowi Scotland
No time for complacency
Sean Anderson, Production Director at Mowi Scotland, highlighted the return to more favorable growing conditions. “This summer has brought lower levels of problematic species of jellyfish and algae, which have historically caused issues for the salmon. However, we cannot be complacent. Jellyfish and algae may still challenge us in September, so we remain vigilant.”
Looking ahead, Mowi Scotland is preparing for a critical operational phase, including the movement of salmon from the Loch Etive post-smolt programme to seawater farms at Muck and Rum.
Anderson praised the dedication of the farming teams: “Our skilled and passionate farmers are working tirelessly to protect the fish in our care, no matter the weather conditions.”
Hadfield also acknowledged the exceptional performance of the Loch Erisort team, which harvested over 10,000 tonnes of salmon this year. “In a rare break from precedent, it’s only right to single out the team at Loch Erisort for their outstanding work,” he said.
