Scotland’s clouds have a silver lining for Mowi
Salmon farmer says fish are thriving as dull summer helps keep challenges in check
While the weather this summer hasn’t been the greatest in Scotland, the relatively cool temperatures and cloudy skies have certainly suited salmon and the companies that grow them.
After several years of warmer-than-usual sea temperatures, they have now dropped back to normal for the time of year, helping the nation’s biggest producer, Mowi Scotland, to register improved harvests.
Salmon can live within wide-ranging water temperatures, in some regions above 20 degrees, but it’s the tiny organisms that thrive in warmer waters that can cause challenges to the health and survival of salmon and other fish. These challenges brought on by warming temperatures can include jellyfish and sea lice, as well as seasonally lower dissolved oxygen levels, as warmer waters carry less oxygen.
Seasonally average temperatures so far into 2024 have helped Mowi to effectively manage sea lice levels on its fish to the lowest levels seen in 20 years.
Bubble curtains
The company says it’s too early in the season to rule out threatening jellyfish and plankton blooms, but lessons learned from previous years have helped it prepare to ward off these microorganisms with newly installed technologies such as bubble curtains, and a big push on harmful plankton identification through training, use of drones, and other sampling techniques.
Sean Anderson, Mowi Scotland’s production director, said: “It’s still early on in the challenging summer period but, so far, our salmon are faring very well. They are feeding to expected appetite, and we are managing to deal with the minor plankton blooms witnessed so far by implementing our mitigation technologies. After a few challenging years it’s been nice to have Mother Nature be gentle on us – our salmon are thriving, and they look amazing.”
Ben Hadfield, Mowi’s chief operating officer farming for Scotland, Ireland, the Faroes and Canada East, got a look at some of the company’s fish during visits to sites in the Uists this month, which including calling in on farm manager Calum “Chin” MacDonald to celebrate his 35-year anniversary at Mowi.
In an interview with Fish Farming Expert early this year, Hadfield said an expected return of normal sea temperatures, combined with Mowi Scotland’s expanded wellboat capacity to combat amoebic gill disease with freshwater baths, would benefit the company’s fish, and he’s so far been proved correct.
“The first half of this year has yielded excellent biological results, with salmon harvests across all sites yielding better than 97% average of superior, top-quality salmon,” said Hadfield.
“I was pleased to travel about our farms this past month and meet many of our dedicated farmers, like Chin who is celebrating 35 years with the company, who are very proud of the high-quality salmon they are caring for.”
Mowi Scotland reports an increase in harvest volumes and larger average weights for the first half of 2024 compared to the same period in 2023: 33,705 gutted weight tonnes (2024) versus 29,651 gwt (2023).
