A deadly virus is threatening Tasmania's lucrative salmon-farming industry, with the Australian State's Environmental Protection Authority (EPA) confirming on Tuesday that 1.35 million salmon have died since October last year.
Believed to be transferred from wild populations in the Macquarie Harbour, the disease known as pilchard orthomyxovirus (POMV) has had a severe effect on a number of commercial fish-farms operated by Huon Aquaculture, Petuna and Tassal.
"It hit all three companies across the majority of leases, so that is troubling from the point of view of the management of that disease," EPA director Wes Ford told local media.
At the moment, the area's salmon producers are investing heavily in the search for a vaccine.
But in the immediate time frame, the EPA has announced a policy to reduce Macquarie Harbour's biomass limit by over 20 percent over the next two years, in an attempt to ease the spread of the virus.
"POMV can be exacerbated by stress caused by heat, low oxygen, and I think this summer we've seen some elevated temperatures and clearly some concerns about oxygen," Ford said.
"My view is that it is prudent to adopt an approach which reduces the biomass for a sufficient time to allow harbor response to be monitored and interpreted meaningfully."
"This further reduction is warranted to reduce the pressure on the harbor and allow for further recovery."