That amazing salmon run—were we wrong to be worried?

Commentary by Elizabeth May | September 16, 2010
Reprint from Volume 22 Number 17 | Island Tides

It seems a lot longer than a year ago that I wrote my first column in Island Tides, ‘From cod to salmon: when do we ever learn?’

Last year, the front pages of our newspapers screamed out the news of sockeye salmon collapse. Over 10 million fish were ‘missing.’ Citizens were demanding answers and the federal government launched commission to investigate the mystery of the missing fish.

This year, the Cohen Commission is underway, but the salmon news could not be more different. This year’s salmon return is the largest since 1913. Some twenty-five million Fraser River sockeye have returned, compared to the dismal less than one million last year. Last year’s salmon run had been predicted by DFO to be a bumper year, with ten million fish expected. This year DFO had no expectation of a huge return. I guess the one constant in fisheries science is that DFO predictions are unreliable. To put it mildly.

Some in the anti-environmental crowd have been triumphant. In the Globe and Mail Margaret Wente used this year’s amazing sockeye return as a cudgel to beat the David Suzuki Foundation, environmentalists in general and Alexandra Morton, in particular. (‘BC’s fishy salmon science,’ September 2, 2010). She claimed that all of the above had received millions in support from fat-cat, US funders to attack the fishfarm industry.

As anyone who knows Alexandra Morton knows well, the charge is outrageous. She survives on next to nothing and small donations somehow keep her campaign (and her dear self) alive (see also her ad in Attractions, page 10). The question is not how much money Alexandra receives, but how she manages to survive and be so effective on so little.

Wente also trumpeted that the collapse of ocean life is a much greater threat than global warming, and then went on to proclaim that the successful run this year somehow proves the sealice from open pen salmon farms is not a threat to wild salmon. Fish farms, according to Wente, will be essential to feed the vast and growing populations of the world’s hungry. She made no mention of the carnivorous nature of salmon and the larger quantity of wild fish that are taken from hungry human mouths to feed the farmed fish.

Others have decried the ‘waste’ of fish as constituted in the sockeye that are not caught by fishermen. Some fishermen have demanded DFO abandon the precautionary principle and expand the fishery, even though the relatively healthy sockeye run is intermingled with threatened coho.

And the idea that too many salmon returning to the river (known as ‘over-escapement’) can cause roe to stack up in the rivers, resulting in a decline in survival has no scientific basis. That notion was put to rest in 2004 by the Pacific Fisheries Resource Conservation Council (PFRCC). At the time, PFRCC Chair, the Honourable John Fraser said, ‘This long over-due paper brings much needed science to the question of over-escapement and salmon stock collapse. On the basis of the data available there is no evidence that higher escapements have resulted in stock collapse….’

Meanwhile, many ecologists have weighed in to explain that there is no such thing as ‘waste’ in nature. The abundance of nutrients from the dying sockeye of 2010 will renew health in a vast web of life that includes forests, grizzly bears and future salmon.

The science of the variables and factors impacting sockeye salmon population is complex. The build-up of greenhouse gases (which Wente ironically claimed is a non-issue compared to the decline of ocean life) is actually a key factor threatening marine life—through both temperature and chemistry. Salmon fry are extremely sensitive to water temperatures and as BC rivers warm up, the salmon are threatened. Globally, the transfer of atmospheric carbon to carbonic acid in ocean waters is a huge threat. Carbonic acid can cause shells to disintegrate, threatening life at the base of the food chain.

A recent study in Nature, co-authored by Canadian leading scientist Boris Worm, found that the world’s oceans are experiencing a dramatic decline in phytoplankton, as much as a 40% decline over the last 40 years.(‘Global phytoplankton decline over the past century’—Nature, July 29, 2010).

The authors speculate that a rise in ocean temperature could be causing the loss of phytoplankton. A nasty feedback loop lurks here. Phytoplankton absorb carbon and release oxygen through photosynthesis. Less phytoplankton means a weakened carbon sink, and more carbon to turn into carbonic acid.

We have many unknowns in fishery science. The mix of factors, the impact of environmental conditions once the salmon leave our waters and live in the wild and open ocean, the availability of food, the impact of sealice, other pathogens, and pollution, all have an impact.

We should celebrate the return of the sockeye this year, but it would be grossly irresponsible to herald one year’s return and declare that all is well.

The mystery of the 2009 missing salmon and the miracle of the abundant 2010 sockeye are both worth investigation. We would be wise to adopt an attitude of humility in the face of all we do not know.

Elizabeth E. May, Order of Canada, lives in Sidney. She is leader of the Green Party of Canada and nominated candidate in Saanich–Gulf Islands.