A matter of life and death

WALKING by a river in British Columbia, during our recent holiday, we noticed lots of tiny fish – parr, last season’s salmon, readying themselves for the big adventure of swimming out to who knows where in the Pacific ocean. A week later, we were in the islands of the Great Bear Rainforest off the BC coast, watching the pathetic struggles of the salmon as they make their last journey back up the rivers to the place where they were spawned three or four years before, and carefully trying not to step on the dead and dying salmon on the river banks and meadows.

And so, in less than ten days, we saw the beginning and end of one of the world’s great life cycles – and began to understand, for the first time, why this keystone species is so vital to its environment.

On our voyage up and down the channels and inlets of the rainforest we often saw salmon swimming and jumping, and to people from Britain, where salmon are now so precious, we thought we saw a lot – until we met Ralph the Creek-Walker in his piratical painted boat. Ralph “walks” the creeks and inlets of part of the reserve, counting salmon. He’s been doing it for more than 20 years so even if his methods are not entirely scientific they are consistent. This year so far he has used his click-counter to record about 4,500 – he would normally expect about 40,000. That tells you a lot about the impact of the many pressures on this critically important fish – climate change, specifically lack of rain this year, pollution of the oceans, over-fishing, the impact of salmon farms (which in addition to bacteria and lice in the water also result in Atlantic salmon being released into the Pacific wild) …

The salmon – many varieties, including the smaller pinks (affectionately known as Humpies), the coho, the chum, the sockeye and the huge chinook (also known as king) – are central to the life of everything in the rainforest and coastal areas of British Columbia and Alaska. They are a vital part of the economies of both the Canadian province and the USA’s 49th state, and an indispensable element of the income and the diet of Canada’s First Nations peoples and Alaskan natives.

Equally important is the salmon’s essential contribution to the diet of the Pacific raincoast creatures – the grizzly, black and rare Spirit bears, the coastal wolves (who eat only the brains, which are high in omega-3 fatty acids, but not the rest of the fish, which contains parasites toxic to canids), the ravens, bald eagles, seagulls and other scavenging and opportunist birds of the region.

Even more remarkable is the salmon’s contribution to the ecology of the region – the millions of decomposing fish are part of the life cycle of the rainforest. Most significant – and surely surprising – is the role of the salmon in fertilising the forest. The bears who feast on the spawning salmon don’t eat on the river – as we saw, watching a grizzly, two black bears and, remarkably, two Spirit bears, they drag the carcasses into the forest. The remains of the salmon contain vast quantities of nitrogen that plants need to grow – scientists have discovered that 80 percent of the nitrogen in the forest’s trees comes from the salmon. The researchers used nitrogen and carbon isotopes to quantify the uptake of salmon-derived nutrients by mosses, herbs, shrubs, trees, insects, and were able to measure what they call “salmon signatures” in the yearly growth rings of ancient trees.

In other words, the salmon – born in the rivers of Washington state, British Columbia and Alaska, living out their adult lives in the Pacific ocean, returning to their birth rivers to die – are crucial to the long-term survival of the region’s temperate rainforests and all its inhabitants.

So the title of this leader is not a cliche or a metaphor – it is a literal statement of the importance of salmon to these Pacific coast communities, and that in turn is a microcosm of the problems facing coastal communities everywhere, and by extension all life on the planet. We are inter-dependent and, as a keystone species is eroded, so we all face a diminution of resources, physical, ecological and cultural. It is, truly, a matter of life and death.

Fanny Charles

• For more information on the threats to the Pacific raincoast and the Great Bear Rainforest, visit the Raincoast Conservation Foundation website, www.raincoast.org; the Sierra Club of Canada website, www.sierraclub.bc.ca/coastal-rainforest-at-risk/