The Cohen Inquiry is urging an immediate eight-year freeze on new net-pen salmon farms in the Discovery Islands between northern Vancouver Island and the B.C. mainland.
Farms in that area should be prohibited outright in 2020 if the Department of Fisheries and Oceans cannot confidently say by then the risk to wild salmon from aquaculture there is minimal, the inquiry's three-volume report says, and the ban should be immediate if evidence of elevated risk arises sooner.
No single culprit – not fish farms, overfishing, pollution, natural predators or global warming – gets primary blame for the two-decade decline of Fraser River sockeye salmon.
And while commission head and retired Justice Bruce Cohen said he saw "no smoking gun" in the evidence he heard, key recommendations aim to limit the possible threat from aquaculture.
"Mitigation measures should not be delayed in the absence of scientific certainty," Cohen said, adding farms in the Discovery Islands of Johnstone Strait have potential to introduce exotic diseases and aggravate existing ones in wild fish.
He also recommended DFO no longer be charged with promoting the salmon farming industry to prevent "divided loyalties" or conflicts of interest from compromising its duty to defend wild fish.
"As long as DFO has a mandate to promote salmon farming, there is a risk that it will act in a manner that favours the interests of the salmon farming industry over the health of wild stocks."
Critics have accused DFO of siding with the aquaculture industry while failing to protect wild stocks amid years of budget cuts and mismanagement.
The industry contends it's the victim of a vendetta by environmentalists who have alleged farm-linked virus infections in B.C. salmon that federal food inspectors have refuted.
If Cohen's recommendations are followed, existing farms in the Discovery Islands could continue operations – unless the fisheries minister decides before 2020 that they pose a "more than minimal risk of serious harm" to migrating Fraser sockeye.
DFO should draw up new siting criteria for fish farms that take into account Fraser sockeye migration routes and the latest evidence on the risks to them, Cohen said.
"If existing salmon farms do not comply with revised siting criteria they should be promptly removed or relocated."
B.C. Salmon Farming Association spokesman Stewart Hawthorn said only nine of 70 B.C. salmon farms are located in the Discovery Islands and predicted the recommendations will have very limited impact on the industry.
"He's particularly concerned about one small area," he said. "We're very happy to do more research there. Our farming practices are second to none."
While the inquiry findings were being prepared, the federal government this year significantly downgraded habitat protection laws and is now planning cuts to front-line DFO biologists.
Cohen warned Ottawa further cuts to DFO are dangerous to B.C.'s iconic salmon species and run counter to his key finding that much more research is needed.
"The shrinking resources of government, which may result in delays in implementing reforms and research, mean that the stressors to which sockeye are exposed and the deterioration of sockeye habitat will continue," he said in the report.
He also criticized Ottawa's move to alter the environmental assessment process for major projects like oil pipelines.
Cohen called last spring's legislative amendments "troubling" and said they appear to take DFO "in a very different direction" from the advice of many experts in the field to protect fish habitat and promote biodiversity.
The report says sources of stress specific to the Fraser – such as pollution and development – have likely played a role in the decline.
But he said troubled fisheries beyond the Fraser system suggest broader problems in marine waters play a big role.
"I heard enough evidence about warming waters to conclude that climate change is a significant stressor for sockeye and in combination with other stressors, may determine the fate of the fishery."
Cohen also urged the implementation of the 2005 Wild Salmon Policy and provisions for no net loss of habitat.
Leading conservationists said they would have preferred an immediate aquaculture ban but most hailed the report.
"He obviously didn't hear enough to say 'Get the nets out of the water,'" said Georgia Strait Alliance executive director Christianne Wilhelmson. "But I think he came pretty close to saying that."
She said the report offers a "solid plan" to restore Fraser salmon runs – if the federal government implements it and stops gutting research and habitat protection provisions.
"We have an ecologically ignorant federal government right now, so I'm wary," Wilhelmson said.
"Anyone who has skin in the game of sockeye salmon on the Fraser River has to put public pressure on this government in Ottawa to make sure this report gets legs and keeps moving," added Sto:lo fisheries advisor Ernie Crey said. "Or else it will surely sit on a shelf."
The inquiry heard from more than 170 witnesses and sifted through more than 2,000 reports or other pieces of evidence.
Cohen was appointed by the federal government after less than 1.5 million sockeye returned in 2009, far fewer than the more than 10 million expected.