Food-poor ocean waters warmed by climate change likely played a significant role in the death of millions of sockeye salmon in British Columbia's Fraser River ahead of what was supposed to be a bumper year, says a scientific think-tank.
A group of more than 20 ocean and ecology experts gathered in Vancouver this week to discuss possible explanations for this year's salmon collapse and announced their assessment Wednesday, saying they want to keep the issue afloat with a judicial inquiry approaching.
Last month, Prime Minister Stephen Harper appointed a B.C. Supreme Court judge to probe the collapse of the stocks, but the scientists say there's much work that can be done in the meantime.
The group recommended improved forecasting, more ocean-based marine research and a more precautionary approach to fisheries management.
"It's really important that we don't just sit back and do nothing for 18 months while the inquiry is unfolding," said Mark Angelo, chair of the Pacific Fisheries Resource Conservation Council.
Fish likely died young
The federal Fisheries Department had estimated more than 10 million sockeye would return to the Fraser River this year, but only about one million showed up.
That huge shortfall forced the closure of commercial fisheries along the Fraser, as well as aboriginal food fisheries for First Nations in the area.
Sockeye is the most sought-after and high-priced type of salmon.
Using their combined expertise and as much official data they could gather, the scientists concluded the missing sockeye likely vanished when they were still young and migrating toward the sea.
They suggested that in either late spring or early summer of 2007, ocean conditions probably hurt the fish's chances of survival.
"If you're looking at warmer temperatures and a lack of food, that could well be a cause of mortality for large numbers of fish," Angelo said.
However, the group didn't rule out other factors, including pollution and lice from fish farms.
John Reynolds, a researcher at Simon Fraser University who was also part of the group, noted that sockeye stocks are showing a long-term decline and any research on the species must keep that in mind
"This is now the way that things may well be for the future, especially under the predictions we have for climate change," said Reynolds, who holds the Tom Buell chair in salmon conservation.
Decline could be long term
"A lot of the problems that these fish had been experiencing in the past are probably going to get worse rather than better. We're hopeful that won't be the case and we're trying to do everything we can now to give these fish a chance."
The group said the methods used to regularly monitor the stocks should be tailored to the Fraser River sockeye — as opposed to the broader guidelines that also apply to other fish.
No one from the Fisheries Department attended the scientists' gathering, citing the ongoing inquiry. However, Angelo said a representative from the inquiry itself was there.
Despite the long-term decline of the sockeye population, Angelo said it's important not to give up.
"We may not return to the boom times in terms of runs that we saw a few decades ago," he said. "But, that said, our hope is that certainly we can continue to sustain a significant amount of fish within the Fraser system."