Uncovering the mystery of B.C.'s disappearing sockeye | Science Matters | David Suzuki Foundation
Photo: Uncovering the mystery of B.C.'s disappearing sockeye

As populations decline, so does genetic diversity. This diversity allows salmon to adapt to the challenges they face and keeps the populations strong and healthy (Credit: Todd Radenbaugh via Flickr).

By David Suzuki with Faisal Moola

The Fraser River's sockeye salmon are in trouble. And when the salmon are in trouble, we're all in trouble.

The number of sockeye returning from the ocean to the Fraser River this year is one of the lowest in the past 50 and follows two years of dangerously low returns. In fact, we have witnessed decades of decline for diverse sockeye populations from the Fraser Watershed, some of which are now on the brink of extinction.

Many salmon runs besides Fraser sockeye are also endangered, while others have disappeared altogether. As populations decline, so does genetic diversity. This diversity allows salmon to adapt to the challenges they face and keeps the populations strong and healthy.

The total disappearance of Pacific salmon would be devastating not just for First Nations and families that depend on the fish for food, but for all who consider salmon a healthy and tasty food source and who rely on the money salmon fishing brings to the economy. Salmon are also essential to the healthy functioning of ecosystems. They bring nutrients from the oceans to the rivers and forests and are a valuable food source for whales, bears, birds, and other wildlife.

The Fraser sockeye fishery is one of Canada's most valuable, accounting for close to 50 per cent of the economic value of all salmon caught in B.C. Their extremely low returns have been called a mystery because finding one simple cause or solution is difficult. However, even though we can't always link an exact cause to every salmon population decline, we do know the major threats, and that gives us hope that we can change things for the better.

Sockeye have been heavily fished over the years, their spawning habitat in rivers and lakes is being destroyed, their survival is threatened by warming oceans and rivers due to climate change, and they are vulnerable to sea lice and diseases from open-net salmon farms.

While we need to invest more funding in science to understand the exact details behind saving our disappearing salmon, we can and must take precautionary actions to curtail activities that we know harm salmon. Canada's Wild Salmon Policy provides the tools to do this, but although the government adopted this policy in 2005, it has yet to fund it and put it to work. Now is the time to do so.

Specifically, we need to work with government and industry to find ways to catch salmon from healthy stocks while avoiding catching salmon from threatened populations.

Freshwater habitat needs to be conserved and rebuilt, and destructive practices such as converting fish-bearing lakes to mine-tailings ponds or destroying streamside vegetation should be stopped.

We must also make sure that seafood labelled as sustainable truly meets the necessary criteria. Third-party eco-certification, like that offered by the U.K.-based Marine Stewardship Council, must be reserved for fisheries that are well-managed and don't further endanger threatened salmon populations.

We need to change salmon farming to remove the impacts of sea lice and disease by creating a thriving closed-containment industry that separates farmed fish from wild.

Canada must also combat global warming by committing to major reductions of greenhouse gases at upcoming negotiations in Copenhagen if the salmon are to survive their long journey from spawning grounds to the sea and back over the long term.

Fortunately, leaders are starting to emerge in the struggle to protect the salmon. Fishermen are working with First Nations in the Skeena watershed to use beach seines to selectively harvest abundant salmon runs. Commercial-scale trials of closed-containment salmon farms are underway off the East Coast of Vancouver Island and at other sites around the world. Municipalities such as Maple Ridge have adopted improved development practices to protect salmon streams.

These efforts employ a holistic, ecosystem-based approach that acknowledges the many factors that affect salmon's ability to survive and thrive.

By embracing our role as a significant part of the ecosystem and acting with the knowledge that we are connected to it for good or for ill, we have a chance to reshape the way we fish, build communities, and live our lives so that salmon remain a healthy part of this coast. We will all be richer if we succeed.

August 28, 2009
http://www.davidsuzuki.org/blogs/science-matters/2009/08/uncovering-the-mystery-of-bcs-disappearing-sockeye/

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