Diseases causing the death of farmed Pacific salmon in 2009. (Graphic: Ministry of Agriculture of CB / FIS)
Govt reveals what killed BC's farmed salmon
Friday, October 01, 2010, 23:40 (GMT + 9)
Eighty per cent of the Atlantic salmon mortalities at British Columbian (BC) farms last year were not due to infectious diseases, according to an audit done by the provincial government. The findings were reported in the Ministry of Agriculture and Lands’ Animal Health Branch – Fish Health Report for 2009.
Atlantic salmon at the farm level exhibited the following infectious diseases: mouth myxobacteriosis was found in 11 per cent of the dead fish and the viral hemorrhagic septicemia (VHS) virus’s North America strain was present in 4 per cent of the cases.
Fifty-nine per cent of the dead Pacific salmon at the farm level were found free of infectious diseases, while 35 per cent were found have died from bacterial kidney disease and 6 per cent from vibriosis, Westcoaster reports.
All the diseases are endemic to BC wild fish populations. The industry is abiding by the 2008-9 sea lice management strategy, according to the report.
It also found that, since 2004, sea lice abundance in wild and farmed salmon has fallen, except for a minor rise in the autumn of last year.
The ministry went through 116 salmon-farm health audits and samples from 585 fish known as “silvers” - dead fish that still have silver skins - to reach its results.
The BC Government sampled approximately 8-10 per cent of silver carcasses.
Coordinator of the Living Ocean Society’s salmon farm campaign Will Soltau said that the audit seems to demonstrate the sector is in compliance and their reporting accurate. Nevertheless, the audit does not cover the health of wild salmon.
He said wild salmon will be exposed to less risk if aquaculture companies shift to closed-containment systems.
And the BC Salmon Farmers Association (BCSFA) informed there were no findings of infectious salmon anemia (ISA) and that only naturally occurring pathogens were identified. Sea-lice levels were low, meaning farms are managing that situation well.
"These fish health reports simply show that a well-managed industry can operate in harmony with the natural environment,” said Mary Ellen Walling, executive director of the BCSFA. "We know that our farms are well-managed and that our fish as well-cared for – so it's good to see the province confirm that information for the public."
Specific findings for Southwest Vancouver Island presented in the report showed that 15 of 19 carcasses from farms did not carry infectious disease. However, three cases showed myxobacteriosis and two showed mouth VHS.
As well, researchers found one case of rickettsiosis, one of bacterial infection and another of furunculosis.
- Report confirms farmed salmon health
By Natalia Real