Stronger in encounters with lice
Tests on three year classes of farmed Atlantic salmon point to the same: there is great variation in how well various salmon families tackle salmon lice. A breeding company is now putting Nofima's research results into practice and offering eggs that are stronger in encounters with lice, reports www.megafishnet.com with reference to Nofima Marine.
Nofima has also found a high genetic association (correlation) between the numbers of sessile and motile adult lice on the salmon. When fewer lice attach to the fish, there are also fewer sexually mature lice. Consequently, testing of various families' resistance to lice can now be limited to the number of sessile lice per fish, in controlled challenge experiments.
"The number of lice per fish determines whether delousing is required. When selective breeding contributes to reducing the number of lice per fish, it will over time result in less delousing events," says Nofima Senior Scientist Bjarne Gjerde. "With fewer lice per fish, the infection pressure on wild salmon populations will also reduce."
Lice resistance on the market
Nofima's research is now being put into commercial use by the breeding company SalmoBreed, which from this year is selling eggs from breeding lines specially selected for increased resistance against salmon lice.
The experiments have been carried out on SalmoBreed's salmon material at Nofima's sea-based research station at Averøy over a period from 2008 to the present day. SalmoBreed has chosen that its future testing of its family material against lice will take place at Averøy.
This research is financed by the Research Council of Norway, the Fishery and Aquaculture Industry Research Fund (FHF) and SalmoBreed AS.