Efforts to combat sea lice infestations through natural means have advanced with the first spawning of farmed ballan wrasse in captivity.
Wild ballan wrasse has been used in salmon farms in Scotland for years as a non-chemical way of controlling sea lice infestations, but reliance on wild catch is unsustainable.
The milestone in the culture of the so-called “cleaner fish” has been reached at a hatchery in Machrihanish, Scotland, which is a joint venture between Marine Harvest and Scottish Sea Farms.
Although the wrasse produced at the hatchery will go to the companies’ salmon farms, the industry will benefit from the research. “The research we have done here is for everybody. We have close links with Norway and other hatcheries in Scotland and the information can be disseminated all around the industry. It is a joint industry project and we welcome the opportunity, if need be, to supply larvae to hatcheries,” says hatchery manager Paul Featherstone.
There are plans to expand the existing facility over the next few years, and the expansion could enable the hatchery to produce 1.5 to 2 million wrasse annually, says Featherstone.
“This is a total win-win situation,” says John Rea, director of Scottish Sea Farms, in a film about the role of wrasse in salmon aquaculture. “Our fish are better off by having this partner in their nets alongside them. It means we have a much lower environmental footprint than we’d otherwise have; the medicine bill is reduced. It makes salmon more suitable.”