Salmon being harvested at a Norwegian slaughtering facility. (Photo: Odin Hjellestad)
Fighting sea lice without chemicals
Wednesday, April 28, 2010, 02:20 (GMT + 9)
Sea lice is the Norwegian aquaculture industry’ greatest burden -- and 15 million lice-eating Ballan wrasse may be the cure.
The parasite has become resistant to chemical treatments, and estimated losses for the industry range from NOK 500 million (EUR 63.6 million) to NOK 2 billion (EUR 254.5 million) yearly. Between 2010-2013, the Research Council of Norway will be investing almost NOK 50 million (EUR 6.4 million) on research to combat sea lice.
New studies show that a fish called the Ballan wrasse can eat heaping quantities of sea lice directly off affected salmon. Villa Organic, Marine Harvest and the Institute of Marine Research’s Austevoll Aquaculture Research Station are leading the scheme.
Dr Per Gunnar Kvenseth of Norwegian seafood producer Villa Organic believes that Ballan wrasse could be key to fighting sea lice without chemicals.
“The fact that Ballan wrasse are so hardy -- and that they maintain such a high activity level throughout the winter -- makes them better suited to the task than any other type of cleaner fish we have experimented with,” explained Kvenseth.
Although Villa Organic normally uses no chemical agents against sea lice, the company said it keeps the parasites in check at least as well as other facilities by using Ballan wrasse.
The main obstacle to using this fish is having enough of them. In the wild, Ballan wrasse of the size needed are in dearth, such that providing it in sufficient numbers will necessitate hatcheries and feeding tanks on land.
Villa Organic has been collaborating with the Austevoll Aquaculture Research Station to solve challenges regarding light conditions and other aspects of Ballan wrasse production. They have developed the routines for raising Ballan wrasse; it takes 12 months of tank feeding for this cleaner fish to be ready for work.
Some 15 million new Ballan wrasse will be needed yearly if they are to combat sea lice across salmon farms. This would mean an industry worth about NOK 250 million (EUR 31.8 million) annually within a few years.
A group of Norwegian salmon farmers plans to produce 100,000 Ballan wrasse this year and 500,000 in 2011.
For supporters of the method, the recent problems plaguing cod farmers in Norway could prove beneficial, because several aquaculture facilities along the nation’s coast currently have empty cod tanks that could be used to raise the cleaner fish.
“These tanks could be converted relatively easily to facilities for raising Ballan wrasse,” Kvenseth noted.
Norwegian cod farmers could thus turn to Ballan wrasse production in times of trouble.
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