VANCOUVER, British Columbia - Sea lice from farmed salmon pose a risk for the health of wild salmon, says a report released Monday by a British Columbia conservation group.
But despite years of questions and accusations from those on both sides of the aquaculture debate, there is a lack of solid scientific research about the effects of salmon farms on wild stocks, said the report by the Pacific Fisheries Resource Conservation Council.
"Unfortunately, our state of knowledge about the potential impacts of salmon farming on wild salmon allows few definitive declarations about where the truth really lies," said the report "Making Sense of the Salmon Aquaculture Debate."
"Instead, we are faced with partial information, untested theories and a great deal of uncertainty."
In November, the group said salmon farms should be shut down temporarily, beginning next month, to prevent a complete collapse of wild pink salmon runs on northeastern Vancouver Island. The group cited a sea lice infestation of wild pink salmon.
British Columbia's Liberal government lifted a moratorium on fish-farm expansion earlier last year over the objections of environmentalists concerned about disease, pollution and the possibility that escaped farmed Atlantic salmon could displace wild stocks in spawning streams.
The recent report by the conservation council, an independent group funded by the government, said good husbandry and preventive measures have reduced the risk of infections and escape at fish farms.
Sea lice pose the most serious and immediate risk to wild salmon, more than viruses or bacteria, the report said.
The introduction of exotic diseases could have had severe, irreversible effects for B.C. stocks, the report said. But preventive measures such as producing, rather than importing, eggs have reduced that risk.
Colonization of British Columbia waters by Atlantic salmon bred at aquafarms is "unlikely, though not impossible," the report said, adding, "There is little we can say definitively about the impacts of salmon farming on wild salmonids."