BY TONI ERKINHARJU Guest columnist
OSLO, NORWAY – Sea lice are external parasites that feed on the skin, mucus, and blood of marine fish, causing wounds, secondary infections, and reduced growth of their hosts. In Norwegian aquaculture, an estimated 10% of the production cost of rearing Atlantic salmon is related to sea lice control.
Since 1991, there have been reports of reduced efficacy and sea lice resistance to several chemotherapeutants. Resistance should not be confused with reduced sensitivity, which refers to a decreased effect of the chemotherapeutants and can be avoided by increasing the dosage. If the population is resistant, there will be no effect of the treatment for any dosage. Considering the possible side effects of contamination of the marine environment, alternative methods for control are preferable.
Two species of cleanerfish used for biological delousing: goldsinny wrasse, left, and lumpfish, right. Trygve Poppes photo
Read the rest and much, much more in Issue 6, 2012 of Fish Farming News. Download now for immediate access and keep the .pdf for future reference.