With its article on the impact of sea lice on sea trout, EAA member Norges Jeger- og Fiskerforbund (The Norwegian association of Hunters and Anglers) sheds new light on the problem raised by this parasite, which is often only associated with wild salmon.
Sea lice, a small crustacean species that feed on the skin and blood of their salmonid hosts, are well known to fish farmers because of their potential effect on the health and well-being of farmed fish. Although sea lice are naturally present in the marine environment, they become more numerous due to the large number of farmed salmon that are in the sea at any given time. Hence, they regularly spark professional media coverage when an alarming rate of wild salmon are infested.
What is still often overlooked is that the salmon is not the only species to suffer from this plague: sea trout is particularly vulnerable to their infestation too. According to a Norwegian Marine Research Institute report, more than half of the sea trout observed in western Norway have an unhealthy infestation of sea lice, as reported by the EAA member ,The Norwegian association of Hunters and Anglers. While wild salmon smolts will swim rapidly through the fjords and out to the high seas, sea trout remain in the fjords and along the coast for a much longer period, making them even more prone to infestation.
Photo credit: NJFF Hordaland
The report confirms the importance of farmed fish production moving to closed technology systems to prevent the spread of lice and salmon escapees. Besides, the Norwegian association of Hunters and Anglers requests that the state of sea trout infestation should become a salient indicator of the traffic light system in place in Norway to regulate the aquaculture sites’ production levels.
See more about the subject on our Norwegian members’ website