Salmon, An Ecosystem Service (LP&M #5)

Vancouver is situated amidst a temperate rainforest and thus receives more precipitation than most of the planet’s major cities. The water we drink comes from one of the three protected watersheds to our north. Our water comes from snowmelt. It comes from trees transpiring and rain falling. It is some of the purist freshwater in the world.

Because it rains for nearly 9 months each year, we can easily fall for the myth of infinite water. However, the other 3 months experience drought…while all 12 months face greater uncertainty each year as global climate change takes hold. Yet, concerning ourselves with how much we use is just as important with knowing how we use it. Because Vancouver is covered mostly by impervious surfaces, the toxics pollutants left by our vehicles and materials we use to build things is delivered by runoff that finds its way into the streams and sewers that run beneath our feet, into False Creek, off to the Burrard Inlet, and out into the Pacific Ocean.

The pollution we leave today has a direct affect upon the spawning salmon of tomorrow. Over 190 species of plants and animals, from algae to humans to whales, depend on the livelihood of salmon. For salmon to thrive, these creatures need clean water in both freshwater streams to spawn and ocean depths to grow into adults.

By taking a look at salmon through the lens of a cascade diagram, we can quickly surmise that the upper two tiers of the diagram consist of the natural features and ecological functions of the clean water habitat(s) of the salmon. The lower two tiers, those that reflect directly the benefits to humans–ecosystem services and the benefits derived from them–are the salmon.

Not only this, salmon can fall into each of the four categories of ecosystem services, as outlined by the Millenium Ecosystem Assessment. They are a provisioning service in the form of a food source. As a third-tier carnivore, salmon can act as a regulating service in the form of biological control. They provide cultural services regarding spiritual and religious views, educational value, recreational and ecotourism value, and a sense of place to the Cascadia region. Lastly, they can be seen as a supporting service through their stature as a keystone species and their ability to help provision the region's temperate rainforest habitat.

Salmon therefore are an ecosystem service. In order for this to remain, keeping our waterways clean must be a priority for sustainable development. Clean water means life for both salmon and humans.