'Deep concerns' over soaring ocean temperatures for Sutherland fish farm business
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SOARING sea water temperatures are causing "deep concern" a Highland salmon farm business has warned.
Loch Duart Salmon, based in Scourie, said it had seen a "consistent and concerning rise" in sea temperatures at its various sites in Sutherland and the Outer Hebrides.
This comes amid wider reports of rising water temperatures in the North Atlantic driven by climate change - a phenomenon which saw the waters off parts of the UK coastline record figures roughly 4C-5C warmer than the long-term average in late spring.
The company warned that the higher temperatures can spark an increase in the number of algal blooms, gill disease in fish and sudden explosions in jellyfish numbers - all of which can be harmful to its salmon.
The rise has prompted Loch Duart Salmon to take a number of steps to protect its stocks from the increases, and it said that this has had some effect, with survival rates for its fish improving despite the environmental challenges.
It said its efforts had yielded "positive results this summer", with "substantial survival improvements across the business" in comparison with previous years.
Mark Warrington, Loch Duart managing director, said: “As a responsible salmon farm, we recognise the importance of addressing climate change and its impact on the environment where we live and work.
"Loch Duart Salmon remains dedicated to developing innovative solutions to ensure the long-term sustainability of our farms. Industry critics often point to mortality numbers in fish farming yet ignore the fact that the environment at sea has changed fundamentally for all marine species, including wild salmon, in recent decades.
"And with survival rates for the peak water temperature months of August and September well up on last year, we know these proactive approaches and staff dedication are working.
For over a decade, Loch Duart has observed an increase in the frequency of algal blooms, influxes of jellyfish, environmentally induced gill disease, and the encroachment of oceanic species in farming locations. The growth of these naturally occurring phenomena can have a devastating impact on fish health and survival.
Loch Duart is combining five approaches to in a bid to face the challenges of climate change.
- Broodstock: All Loch Duart farms are part of a natural Scottish strain broodstock programme. This has been proven to produce salmon which are more resilient to the changing marine conditions.
- Cleanerfish: Their "cleanerfish" programme works to combat the parasites that thrive in warmer water conditions.
- Improving their salmon’s environment: Each site is equipped with an aeration system, boosting water movement and drawing cooler, more highly oxygenated water from depth to improve water quality for the fish, particularly on the calmer, sunnier days during the summer months.
- New technologies: Loch Duart also uses oxygen generation technology at sea, this approach mitigates oxygen depletion events, such as those caused by algal blooms.
- Staff training: Loch Duart has also been keeping staff fully trained on the warning signs to look out for in relation to any environmental changes. These include daily monitoring for microscopic algae and oceanic jellyfish.
Mark Warrington reflects on the future for Loch Duart:
“Despite our concerns for the future of our unique business, due to rising water temperatures and their associated impacts, Loch Duart Salmon is fully committed to confronting these climate change challenges, head-on.
"We spare no effort to uphold the high standards of innovation, fish welfare and environmental stewardship for which we are known. Many of our more traditional small-scale farms and inland locations aid us in doing so. Loch Duart is dedicated in our aim to continue nurturing and rearing the best tasting salmon, with the lowest possible impact on the environment.”
