The salmon farming industry in North America is a highly contentious subject, provoking passionate responses from advocates and detractors alike. The issues surrounding this controversial topic are numerous and varied, and are notoriously difficult to prove. Accordingly, the question of whether the benefits of the industry outweigh any potential detrimental effects leads down a long and convoluted path, with no clear answer at the conclusion of the journey.
The issues surrounding this debate are many, but can be broken down into two basic groupings: socioeconomic, and ecological. Anyone familiar with the modern environmental movement will recognize these two sparring partners. As with most human endeavor, we face a moral choice: how much environmental damage are we willing to risk for the gain of society? The other side of this ethical dilemma is at what point does the integrity of the ecosystem (global or local) outweigh human lives? In the end, we are dependent on our habitat just like any other animal.
The Socioeconomic Question
The advocates of salmon farming contend that the industry is of great socioeconomic benefit. Providing badly needed employment in rural coastal communities, aquaculture replaces jobs lost by the decline of the commercial fishing of wild salmon. Additionally, these ventures provide an economic boost to the region, purchasing supplies, creating jobs in processing facilities and shipping companies, and replacing seasonal surges in cash with a consistent year round economy.
More important than the local effects of salmon farming are the global effects. We are currently in a stage of unprecedented global population growth, and may soon find ourselves lacking the ability to supply even the basic needs of these enormous numbers. Not only is the current infrastructure insufficient for the task, it is actually decreasing in efficiency due to another effect of the incredible growth in population; global warming. As the effects of global warming increase, flooding and storm events also increase, which serve to destroy crops and decrease the available amount of food. Many third world countries rely heavily on crops grown in low land areas such as rice (which accounts for close to 80% of the diet of a large portion of Asians), which are regularly destroyed by these events. A consistent, reliable, and cheap supply of protein in the form of aquaculture products is a critical component to the eventual solution to this dilemma.
The Ecological Cost
The biological and ecological effects of open net pen salmon farming are so numerous and complex that providing detail on the subject far exceeds the scope of this article. Rather, a basic overview of the issues will be provided. To generalize, the effects can be broken down into two categories: large scale effects, and localized effects.
One of the most common arguments against salmon farming is that it amounts to a net negative when considering protein production. Essentially, the salmon require a greater amount of protein than is produced. This is a condition that holds true for any species. A tenant of ecology maintains that each successive trophic level contains fewer organisms, because each individual must consume far more than its own body weight to survive. This basic concept is immutable, and cannot be resolved. The issue at heart is really the source of the protein that salmon farmers use to raise their stock. Enormous numbers of small feeder fish are harvested around the globe and ground down into protein pellets. The ecological impact of this harvest is large and complex. In fact, it is only beginning to be understood, and unfortunately, the major issues likely will not be identified until they manifest, leaving us to react with damage control rather than take proactive steps. In general terms, the food chain is being interrupted by this harvest, affecting all of the trophic levels above that of the harvested species. An ecosystem is called a system for a reason; everything is connected. Eventually, this harvest will begin to affect the entire ecosystem, resulting in a decline of the very stock that is required.
An interesting side effect to this practice can be found in recent studies, that farmed salmon are showing elevated levels of pcb's and other environmental toxins, which do not occur in wild salmon. The culprit is a phenomenon known as biomagnification. Essentially, the organisms at the lowest trophic levels absorb and ingest small amounts of these toxins. As they are consumed, the toxins are passed up the trophic levels to the larger organisms. These toxins remain in the system, accumulating in the internal organs. As they move up the trophic levels, they are found in larger and larger quantities. High concentrations are commonly found in top level predators, such as tuna, sharks, and killer whales, but rarely (if ever) in salmon. By using artificial harvesting methods to collect massive amounts of fish, farmed salmon have been effectively raised to the status of top level predator.
On a localized level, there are many serious side effects to the industry as well. The open net pen system results in a variety of issues, from contamination into the environment, to contamination from the environment. The feeding system results in nutrients, antibiotics, and other drugs being released into the water, as well as concentrated feces accumulating on the bottom around the net pen. Studies show that ecology of the bottom around net pens is decimated after just a few years, taking up to twenty years to recover.
The open pen system also acts as a breeding ground for disease and parasites, such as sea lice. The real damage occurs when wild stocks, without the protection of the vitamins and antibiotics which fortify the farmed stocks, come into contact with these pathogens and parasites. Many salmon farms are located in inlets and bays which contain fresh water streams, to take advantage of protection from waves, replenishing water currents, and the infusion of nutrients and oxygen from the streams. Unfortunately, these streams are used heavily by wild stocks for spawning. In the spring, the new fry essentially have to run a gauntlet of disease and parasites, which has decimated stocks in some areas of the North Pacific coastline.
Lastly, the most commonly farmed species, Atlantic Salmon (Salmo Salar), are not native to the Pacific. Escape incidents have resulted in local stocks being forced to compete for food and spawning ground with the larger, more fit farmed salmon. In addition, wild fry have been predated on, causing a decrease in numbers for certain runs. With every escape incident the chance of the Atlantic Salmon establishing a self-propagating population on the Pacific coast increases. There are a number of documented sightings of Atlantic Salmon spawning in British Columbia streams, as well as unconfirmed sightings of fry.
The Final Analysis
After careful consideration of the arguments as presented, the answer must be perfectly obvious: the detrimental effects of open net pen salmon farming on the fragile ecology of our planet are unacceptable, and cannot be tolerated. Also, the benefits provided by this industry are absolutely critical at a time when the world population is increasing exponentially, and food supplies are endangered by the effects of global warming. The industry, therefore, is indispensable.
How then, are we to reconcile these two opposing and seemingly incompatible conclusions, and save ourselves from having to make an unthinkable decision? The answer unfortunately, is not a perfect one. Local governments must pass legislation banning the practice of open net pen salmon farming, and endorse dry land, closed pen aquaculture in its stead.
The aquaculture industry has argued for a decade that dry land, closed pen systems are not financially feasible. The technology to maintain the current level of production at a reasonable cost is not yet in place, although there are companies with systems in the advanced development stage. North American industry is renowned for its ability to adapt and innovate, but this will only occur when necessary. In other words, an industry will only change when it becomes financially prudent to do so. If the marketplace will not produce the required pressure, it is up to our governments to create it.
As stated, the introduction of dry land aquaculture is not a perfect solution. It will not address the issue of the net negative protein production, nor the ecological effects that this loss of protein is causing. This however, can possibly be addressed in the future through the development of alternative protein sources. The bulk of the negative ecological effects will be eliminated in this scenario however, with the positive aspects preserved.
This is a critical point in time for the human race, and we must proceed with caution. The global population is increasing faster than it has in the history of the world, and with it comes an increase in demand for food, clean water, energy, transportation, and goods. All of this comes with a price in environmental damage, which must be addressed. The demand and corresponding pressure will only increase, and so it falls to us to deal with these issues now, while they are still at a manageable scale.