Salmon have been an integral part of the life and culture of people on Canada’s West Coast since time began. They’re also essential to coastal ecosystems, providing food for bears, eagles, insects, and other animals, and contributing to the magnificence of coastal rainforests by transferring nitrogen and other nutrients to the forest floor when bears and birds feed on them.
This year, we’re seeing an unexpected — some would say “miraculous” — return of sockeye salmon to the Fraser River, with as many as 30 million fish expected to make their way up the river to spawn, almost triple the number originally predicted. Last year, only about 1.5 million returned, far fewer than the 10 million expected.
Although seeing the rivers run red with salmon once again is cause for celebration, we can’t say this signals a reversal of the declines in Fraser River salmon populations that have been occurring over the past two decades. To begin, our understanding of this magnificent fish and its life cycle is limited. We simply don’t know much about what happens to the fish during the two years they spend in the ocean.
And we must remember that one year of good returns doesn’t mean returns will be good for years to come.
This is a “dominant” cycle year. After hatching, Fraser sockeye spend two years in lakes and rivers before heading out to sea, where they spend another two years before returning to spawn. The fish coming back this year are the offspring of those that returned and spawned in 2006. The current cycle has traditionally been the biggest, or most dominant, since early in the 20th century. In 2006, about 13 million Fraser sockeye returned.
The Fraser also has about 40 distinct sockeye populations, and some, such as the Cultus Lake sockeye, aren’t doing that well. Conserving all of these populations to maintain biological diversity is the best way to ensure that overall abundance of Fraser sockeye remains high. And although this year’s runs appear high, they are much lower than they have been in the past.
Before commercial fishing began on the Fraser, as many as 100 million fish are estimated to have made their way back up the river in some years.
We won’t know until later in the fall whether a large number of Fraser sockeye successfully spawned and whether endangered populations returned in higher abundance than in previous years.
Some people have argued that too many salmon are returning this year, and they we must allow the fishing industry to catch more of them if we are to ensure healthy runs in the future.
But all the available science shows that when more fish return to spawn, the following cycle will be more abundant. Salmon are never “wasted”. Even those that don’t spawn provide food for the insects that in turn provide food for the salmon that hatch on the spawning grounds, contributing to the health of subsequent stocks. And they provide food and nutrients for bears, eagles, and forests.
On top of that, the fishing plan for 2010 allows high catch rates even for the endangered populations.
The 2010 plan allows fishing of up to 30 per cent of the critically endangered Cultus stock, even though scientists recommend that fishing should not exceed 12 per cent. Along with habitat damage and loss, warmer waters because of climate change, and parasite and disease impacts from open-net salmon farms, this could pose a threat to the long-term viability of the Fraser River salmon.
After the disastrous sockeye returns last year, and the significant declines for the past 20 years, we must see this year’s Fraser sockeye returns as a hopeful sign that this important, wonderful, and surprisingly resilient creature can be saved. But we won’t save them with guesswork or by greedily fishing as many salmon as possible. We must work hard to reduce all the threats against the salmon, from habitat destruction to overfishing to climate change to open-net fish farms.
And so, let’s enjoy the gift of the sockeye salmon this year, but remember that it’s a gift we can’t afford to take for granted.
Scientist, author and broadcaster David Suzuki writes this column with scientist Faisal Moola. Learn more at www.davidsuzuki.org