The plight of the salmon is a classic predicament of a common property resource; no private ownership is attached to the resource, therefore no control over how extensively it is used. Salmon have been viewed as a commodity to be exploited, their value based almost exclusively in economic terms. Little importance has been attributed to their critical role in maintaining a viable and healthy ecosystem in the Pacific Northwest. Furthermore, even less is understood as to how human manipulation of apparently unrelated natural environments could be a factor in their decline. While a great deal of study has gone into preserving salmon on a micro level, such as stream restoration, harvest limits and adjusting for the immediate needs of the fish, little is known about the macro effects of salmon to their environment or vice versa, the big picture so to speak. Have environmental changes to whole ecosystems reached such a point as to make the salmon decline inevitable? Have human changes to the salmon’s ecosystem so altered situations, like water quality, aquatic food webs in fresh and salt water, spawning habitat, etc., that the salmon will decline for reasons we yet understand and are unable to fix?
It is well documented that the carcasses of spawned salmon are an engine of enrichment, serving as nature’s way of returning nutrients from a rich ocean to nutrient poor inland areas. Over the millennia this transfer has become a necessary function that many species of plants and animals rely. With foundering runs of salmon today, fewer ocean nutrients are getting back. How does this affect the food web for the watershed, for juvenile salmon? If less aquatic forage is available to young fish, the capacity of a watershed in regard to fish populations will be reduced. Coupled with other stresses in a salmon’s life, as fewer fish live and return to spawn, the river will experience an increasing nutrient debt, a self-perpetuating decline of the ecosystem ensues, much like the action of desertification. This is merely a vague hypothesis on my part; an example. When looking into biodiversity and salmon, it becomes infinitely complex and very difficult to pinpoint how any given change to an ecosystem will affect the other members over extended periods of time.As plant diversity is altered in a watershed, water quality and health are affected. Nature has evolved to deal with changes such as drought, fire, floods and the like, but man as altered the landscape so quickly and extensively that nature has not had time to adjust. With every clear-cut, new home and farmer’s field, we alter the natural order to some degree. Our combined actions throw the balance of out whack without understanding the long-term consequences . Yvonne Baskin in The Work of Nature points out:
Even in richly diverse communities, the complex web of interactions among species means that changes in one can snowball to affect others and may alter operations at the ecosystem level aswell. In already sparse communities, the impact will still be greater. (220)
The secondary effects of human actions in an ecosystem are difficult to predict and may happen so slowly as to not be noticeable until it is too late. We just don’t know when we’ve crossed a threshold and must learn to tread lightly, if at all.
As salmon stocks dwindle, so does their available genetic pool. With fewer genetic traits and combinations available, as gene pools stagnate, the stocks lose the ability to adapt. They will not remain healthy and viable in the rapidly changing environments they are forced to endure. Salmon have survived extensive natural upheaval and thrived, but since man has begun to alter the environment in unprecedented speed and scope, the salmon have suffered. The decline of salmon is a mirror to the entire health of the ecosystem; like a canary in a mine.
We are faced with bigger problems than just salmon. If this species can no longer live, it is an indicator that others will go as well, including humans, eventually. The plight of the salmon is a warning of things to come if we as a species continue in our reckless squander of our natural world. If we can make our rivers home once again to healthy populations of wild salmon, we have gone one step closer to saving ourselves.
Michael Mills