April 25, 2007

VHS in the Great Lakes threatens US aquaculture

The viral hemorrhagic septicemia (VHS) virus in the Great Lakes, which has killed tens of thousands of fish in recent years, may threaten inland fish farming, the USDA said on Monday (Apr 23).

VHS causes internal bleeding in fish but poses no danger to humans even when infected fish are eaten. A trout farm in Yorkshire in the UK reported the disease in July last year. In May, another outbreak at a UK farm caused the culling of 250,000 trout.

An emergency order in October to limit movement of live fish caught in the eight states bordering the Great Lakes and two Canadian provinces was issued to prevent the spread of the disease.

The virus could potentially affect the catfish industry, which accounts for a little less than half of the US$1 billion aquaculture market in the US, Jill Roland, a fish pathologist for the USDA said.

The virus first surfaced in the US in May last year in the Canadian side of the Great Lakes: Lake Ontario and Lake Erie.

Apart from limiting movement of fish by humans, little can be done to control the spread of the disease.

However, experts are worried that the virus may enter through a number of commercial farms which are still get their breeding stock from wild fish.