Planet over Profit

To challenge the idea that farming a native species is better, consider the example of farming Atlantic salmon in British Columbia which was began in the early 1980’s. Atlantic salmon were preferred for farming over Pacific’s because of the existing husbandry knowledge, success of farming Atlantic’s in Europe, and the challenges (e.g. aggressiveness) associated with domesticating local species such as Chinook salmon.

As I mentioned, the introduction of exotic species is the 2^nd leading cause of species extinction worldwide. When I heard that the salmon farming industry was based on an exotic species it made absolutely no sense to me given the passionate lectures I had witnessed from ecology professors on this topic. I couldn’t believe that the Canadian government would allow this to happen, but it made good sense economically so the Canadian environment was put at risk by short sighted government managers.

The government denied that there would be any problem with farming Atlantic salmon stating publicly “don’t worry they won’t escape”. Atlantic salmon were soon found to be escaping and the government said “they won’t survive”. Atlantic started showing up in the catches of fisherman as far away as Alaska (where salmon farming is banned) and were observed in rivers near the farms (I have seen Atlantic salmon swimming in rivers myself on the west coast of Vancouver Island). Next the government said “they will not spawn in the wild.” Juvenile Atlantic salmon were observed in 3 rivers in BC. Finally, the government said “they won’t establish a self sustaining population”. So far there is no evidence that Atlantic salmon are establishing a population in BC, however one wonders how long it could take when there continues to be a supply of healthy adult Atlantic salmon escaping and entering rivers where other escaped Atlantic salmon are present. It is important to note that just because a species is exotic does not mean it will establish a population and have an impact. But it does appear that Atlantic salmon are being encouraged to establish a population in BC despite the risk.

So after reading the above you are probably saying to yourself that this is proves that farming native species is better but consider that there is no evidence that Atlantic salmon have established self sustaining populations in areas they have been introduced. On the contrary there is evidence that escaped Atlantic’s can interbreed with wild Atlantic’s and reduce the health of the wild population in the areas where they coexist (e.g. Europe). Although I am not aware of any literature that demonstrates the same effect when farmed Pacific salmon interbreed with wild Pacific salmon the literature suggests that there may be a greater risk in farming Pacific salmon in British Columbia.

With the above noted, this may lead one to question logic of farming salmon in British Columbia or anywhere for that matter. That will be the topic of the next post.