Cleaner fish (or companion fish) are now commonly used in salmon farming around the world. The principle behind it is that the cleaner fish eat parasites such as sea lice which may settle on farmed salmon. The same way that ladybirds control aphids on commercially grown plants.
When our young farmed salmon go from a fresh water environment they are free of sea lice as sea lice cannot live in freshwater. Over the following months, as wild fish stocks pass by our sea farm locations, sea lice migrate from wild fish to our farm stock. Cleaner fish are used by Loch Duart to graze on any sea lice that might settle on farmed salmon stock from surrounding waters. The use of cleaner fish is a non-medicinal approach to sea lice control. Cleaner fish used, principally ballan wrasse (Labrus bergylta), are native to Scottish waters.
The movement of every cleaner fish is handled with great care by Loch Duart staff, not only in the sense of duty of care for the wrasse but also in making sure there is no disease transfer and parasitic transfer. Batches of cleaner fish go through intense screening prior to acceptance by Loch Duart and then approval for transport to the farm.