SSF reports early success with Thermolicer
SCOTLAND’S first Thermolicer has proved highly effective in removing sea lice, achieving 95 per cent clearance, reports a leading salmon farmer.
Scottish Sea Farms has treated more than six million fish since acquiring the £4 million Norwegian made technology earlier this year.
The company spent months researching and training staff in Norway to use the
system and is now cooperating with other fish farmers, sharing the use and knowledge of best practice and reducing the requirement for medicinal treatments in Scotland.
The Thermolicer has been used across the industry by salmon farmers including Cooke Aquaculture and Grieg Seafood. Marine Harvest Scotland also has one of the machines, made by Steinsvik.
Dr Ralph Bickerdike, SSF head of fish health, said: ‘This has been a real breakthrough in the fight against sea lice – having access to a new tool, which works in a completely different way to our other control measures, is a major achievement for the Scottish Industry.
‘It complements the other innovative solutions we are employing, such as biological control.’
The Thermolicer is a machine that uses zero therapeutants in the treatment of sea lice. The lice have a low tolerance for changes in temperature and the new device uses this fact to use water temperatures to eradicate the parasite.
It is a simple and environmentally friendly method that goes beyond the traditional treatments.
Assessing the health status of fish prior to a Thermolicer treatment is an essential part of the decision making process for fish health and welfare. If there is an underlying health issue, due to previous environmental challenges, then other control measures are considered. This strict best practice ensures high standards of fish welfare.
The Thermolicer is being used as part of an integrated sea lice management strategy whereby prevention is the priority, together with cycling of different treatments when intervention is required in order to avoid resistance developing to a specific control measure.
The machine was bought with funding support from Marine Scotland and the Scottish Aquaculture Innovation Centre (SAIC), with partners Cooke and Grieg, as part of an ongoing initiative to deliver non-medicinal approaches to control sea lice.
Cabinet Secretary for the Rural Economy Fergus Ewing said: ‘I am pleased to see the impact our support is having – innovation in this field is exactly what we want to encourage.’
Thermolicer technology has been tested over a nineyear period and is recommended by the Norwegian Veterinary Institute.
More than 30 of the machines are currently in use, most of them in Norway.
Meanwhile, Marine Harvest Scotland has defended its use of a Thermolicer following reports that fish at one of its Scottish sites had been ‘poached alive’ as the water overheated.
The stories, the company said, were ‘completely misleading’. Fish are only exposed to a maximum temperature of 34 deg C for 25 to 30 seconds.
‘It is extremely regrettable we lost fish at Greshornish [Isle of Skye], which we believe was the result of treating fish that had been weakened from other treatments, particularly for Amoebic Gill Disease, in the preceding two months.
‘Human error played a part in this incident. However, these earlier treatments had saved many fish suffering from this environmental gill challenge.’
The experience highlights the fine line in judgement required on how, and when, to treat fish.