Anti-sea lice shields enhancing salmon production for Scottish farmer
One of Scottish Sea Farms’ current salmon crops is outperforming all previous years following the introduction of new anti-sea lice shields, the company has said.
The shields are the latest in a series of proactive, preventative measures by the producer to enhance the health and welfare of its salmon.
Specially engineered to suit Scottish marine conditions, each shield consists of a permeable fabric that lets water and oxygen move freely into fish pens while keeping natural health threats out. This fabric fully encases the pen to a depth of 6 meters, providing a barrier against sea lice that are most commonly found in the first few meters below the water’s surface.
The shields were first introduced at the company’s farm at Slocka, Ronas Voe on Shetland in May 2017. In the nine months since, sea lice levels have remained below the Marine Scotland Code of Good Practice threshold, and the salmon are showing strong growth and biological performance, it said.
Such has been the effectiveness of the shields that Scottish Sea Farms has invested more than GBP 800,000 (USD 1.1 million, EUR 906,050) with two Scottish suppliers – William Milne Tarpaulins in Aberdeen and W&J Knox in Ayrshire – in order to roll-out similar protection to 11 of its other farms.
The company is also working with neighboring salmon growers to synchronize use of the shields, as part of a farm management agreement for those same areas.
“We strive, wherever possible, to replicate the natural conditions that salmon are known to thrive in. As any farmer will understand however, this comes with its own risks as the marine environment presents new challenges all the time. We are continually exploring and investing in new ways of dealing with these challenges, and it’s hugely encouraging to see positive early results such as these at our trial project in Shetland,” said Jim Gallagher, managing director of Scottish Sea Farms.
The shields are part of the company’s wider GBP 11.8 million (USD 16.5 million, EUR 13.4 million) investment in 2017 to enhance the health and welfare of its salmon. More than 85 percent of this outlay has been on non-medicinal approaches.
Specifically in terms of controlling sea lice, key areas of investment include:
• More than doubling the use of cleaner fish in the last year (76 percent of which are now from farmed origin, keeping the company on track to use farmed-only stocks by 2020)
• Developing a new net cleaning pressure pump to keep pens free from marine build-up, simultaneously enhancing fish health and welfare and increasing the effectiveness of cleaner fish
• Ongoing investment to increase understanding of cleaner fish, with the insights gleaned being shared with the wider industry
• Co-funding new Thermolicer technology that bathes salmon in such a way as to dislodge and catch sea lice, with up to 95 percent effectiveness.
In turn, the need to administer medicines has significantly reduced, with six of the company’s farms requiring no sea lice interventions at all during 2017.
Furthermore, with sea temperatures rising in Scotland, resulting in new planktonic organisms that are potentially harmful to the health of fish gills, the company has also invested GBP 200,000 (USD 279,426, EUR 226,503) in environmental data monitoring equipment, as well as GBP 260,000 (USD 363,168, EUR 294,306) on new underwater camera systems.
“Even a seemingly slight increase in sea water temperatures of 0.5 degrees can have an impact on the marine environment. This new data monitoring equipment is enabling real-time analysis of key markers such as salinity and oxygen concentration, helping us to make informed decisions to maintain high standards of welfare for the fish under our care,” said Ralph Bickerdike, head of fish health and welfare at Scottish Sea Farms. “Complementing this, the new underwater cameras enable us to observe the fish within the pens and respond swiftly should there be any changes in their natural behavior.”
Scottish Sea Farms operates 46 farm sites, two processing plants and employs 449 people.