U.S. senators seek new study of deadly salmon virus

By:  Craig Welch
Source: The Seattle Times

State and federal scientists concerned about news that two wild sockeye smolts have been found carrying a highly contagious virus related to one that killed millions of farmed salmon in Chile agree on this: they need more information.

Three Northwest senators want them to get it.

Late Wednesday, U.S. Sen. Maria Cantwell, D-Wash., and Alaska Sens. Lisa Murkowski and Mark Begich asked Congress to require federal agencies to research the risks and threats from the discovery and report back on their findings within six months.

The senators are proposing an amendment to an agricultural appropriations bill that would kick off an emergency research effort to figure out how much of a threat the virus may pose to wild, hatchery and farmed salmon in Alaska, Washington, Idaho, Oregon and California.

"We need to act now to protect the Pacific Northwest’s coastal economy and jobs," Cantwell said in a statement. "Infectious salmon anemia could pose a serious threat to Pacific Northwest wild salmon and the thousands of Washington state jobs that rely on them. We have to get a coordinated game plan in place to protect our salmon and stop the spread of this deadly virus."

The proposed amendment comes just two days after researchers at Simon Fraser University announced the results of laboratory testing that revealed two of 48 sockeye smolts tested from Rivers Inlet in northern British Columbia were carrying infectious salmon anemia, also known as ISA. It's the first time the virus -- which in its virulent form has been found to be deadly to Atlantic salmon, but harmless to humans -- has been documented along the Pacific Coast.

Fish-virus experts from the U.S. Geological Survey to the Washington Department of Fish and Wildlife called the discovery alarming even while they acknowledged the tests results don't make clear how wide-ranging the virus is. The results also have not yet been confirmed by additional testing.

"We found sequences of this virus in two samples of wild sockeye -- that's all," said Fred Kibenge, the highly regarded scientist who performed the tests. "There was no link to disease, no indication of a massive outbreak, and we don't know if it's virulent or not.

But anytime it's present you have the potential for an outbreak.

"This is probably the single most-feared virus in the fish industry," he said. "ISA is a very dangerous disease."

The virus first surfaced in farmed Atlantic salmon in Norway in the early 1980s and since has ranged as far as Scotland and Chile and northeastern North America.

So far, there's no evidence this virus has ever harmed wild salmon populations, even wild Atlantic salmon populations. James Winton, a fish virologist at USGS in Seattle, found several years ago that several species of Pacific salmon exposed to the virus in a lab were resistant to disease.

But the virus is a fast killer of farmed Atlantic salmon, which are reared by the tens of millions in net pens in British Columbia. And it also has great potential to mutate, which raises concerns about its impact on wild salmon.

"The big question is, if it does adapt, how serious will the direct mortality be?" asked Winton.

"But more concerning is Pacific salmon just don’t need another threat. Adding one more even relatively minor disease issue on top of all the other threats they face could be pretty serious. And if the disease got into hatcheries or other populations undergoing other stressors, it could be much worse."

Right now, though, "we just don't know enough."

Cantwell's amendment would not seek new money, but would direct an interagency team of scientists within the Commerce, Agriculture and Interior departments to make it a priority to gauge the prevalence of the virus, discover transmission pathways and figure out management strategies to deal with the potential threat.