From Chris Whites Bio. World:

This is a hot topic with a lot of opinions and sides accusing others of being wrong. I suggest we step back and look at the science, the biology. From there, I invite your critical thinking to make your own decision.

If we look at a food chain, when something eats something else, on average 10% of the energy of the food source is absorbed and becomes part of the predator. The other 90% is lost through metabolism, heat generation, activity, and other forms of energy use.

To look at this concept an easier way, say hypothetically we need an acre of food to survive, whether it be vegetable, meat or fish. If we had 10 acres of vegetables, you could feed 10 people. If you fed that same 10 acres of vegetables to cows, you could support one acre of cows as only 10% of the energy is conserved and only one person from that acre of cows. Because you have two links in the food chain with cows, 90% of the energy has been lost compared to a person directly eating the vegetable. That is generally why the more meat eaters we support, the less people we can feed on earth.

Now let’s apply this to the farmed salmon phenomenon. I was in Peru a few years back working on some dolphin research. Peru happens to exhibit a natural upwelling system, one of three places in the world where deep nutrient cold water is continually brought to the surface making the waters incredibly productive. The Peruvian Anchovy is a small fish close to the bottom of the food chain that is the great benefactor of these waters, proliferating in huge numbers. Going along the coast, I saw countless fish factories processing these Anchovies. Processing the Anchovy into fish meal, it is then exported mostly to China, Germany and Canada among others where it is fed to farm Salmon.

So what we ultimately have is a public resource the Anchovy, that is used to privatize a resource of Salmon and in the process we lose 90% of the energy.

To me, even if we correct the problems of using invasive Atlantic salmon on the west coast of Canada, decreasing wild salmon susceptibility to getting farmed salmon sea lice, and cleaning up the dead zones around these farms, the fundamental process of feeding one fish to another to privatize the resource is fundamentally flawed.

So what can we do as consumers? There is a natural flow of energy up the food chain and wild salmon will do their best to survive and often in great numbers. This allows us to take a certain amount of wild salmon out of the system each year. So eat wild salmon, but maybe eat it less often and when you do, enjoy it for the very special treat it is. We can focus on eating closer to the bottom of the food chain. Discover the Anchovy and other smaller fish like Herring. They actually have less heavy metals and are better for you! Finally, eat vegetables! They are good for you, tasty, and about as close to the bottom of a food chain as one can get. The more vegetables we eat, the more other people will have a chance to eat.