Contributing Monkie G Living Staff Monkies
Published on September 7, 2008
Apparently hairy mammals are not the only ones that fear the words “louse” and “lice.” Sea lice, the insidious parasite that infects adult salmon, is leaving many salmon farmers in the Broughton Archipelago northwest of Vancouver, BC scratching their heads.
In a report released last month in the Journal of Science, lice that flourishes on salmon farms is infesting juvenile wild salmon as they journey out to sea. The problem is pretty simple actually. Sea lice usually only infects salmon out at sea and dies off as adult fish make their way into fresh water where the lice cannot survive. Juvenile salmon are protected from contact with lice until they are out at sea where they are bigger and stronger. The large farms close to river mouths are exposing the juveniles to lice when they are too small to survive an infestation and wild populations are declining rapidly as a result.
The prognosis for wild salmon is not good; researchers estimate that farms have already killed 80% of the wild salmon around Broughton Island and this number could reach 99% in another 4 years. Farmers have reacted, saying that it is irresponsible to claim that the farms are the only culprit in such a high kill-off rate – but researchers have shown that the high death rate is found only in areas where there are farms.
The solutions include completely enclosing the farms so that no lice can escape or moving the farms farther from fresh water so that the fish can mature before they encounter lice. Neither solution is palatable to the farmers, mainly because of cost.
Here’s another analysis of cost…
The financial cost of losing another wild salmon population: tourism is sure to decline as wild fish in the rivers decrease.
The intrinsic cost of losing another wild species to human meddling: Priceless.