あ まりに個人的盛り上がりなpostをして後味が悪いので(苦笑)、一つ普通のお話を残しておきます。またヒューの話になってしまって申し訳ないのだけれ ど、前学期中に彼が生物学のクラスで学んできた時の講義内容です。実際、このクラスの先生はこのお話で新聞に載ったので真実味は高いです。
で、その講義内容なのですが、結論から言うと養殖サーモンは買わないように、という事。理由を述べていきましょう・・・
サー モンが1キロのプロテインを作り出すには3キロのプロテインを摂取する必要があります。その大量の餌の元となるアンチョビといった小魚は主にチリ・ペ ルーから来ています。人間が漁をしすぎるため、8年後にはそれらの地域から小魚が居なくなってしまうと予測されています。小魚が居なくなる、という事はそ れらを食べる大きな魚も居なくなってしまうという事。=何千という漁師さんのお仕事が無くなってしまいます。
養殖サーモンに餌を与える際、取った 小魚のうち、余分なところは取り除いて脂肪分(ファット、オイル、プロテイン)だけを与えるため、その分毒素や化学物 質だけが残り、それはサーモンが普通に小魚を食べるのと比べると10倍も毒性が強いのです。(これは人間に置いて考えると脂肪分だけ食べ続けている状態と 言えるだろうか。不健康だよね。)
狭い場所で過密にサーモンを養殖するという事はシーライス(海のシラミ?と直訳していいのかな?)の問題も起こ ります。本来ならシーライスが存在していて も問題無いはずが、サーモンが過密状態の場所では簡単に増殖していく事ができ、異常発生してしまいます。このシーライスは養殖内のサーモンだけでなく、そ の養殖場の近くを通り過ぎる野生のサーモンにも寄生して、結果多くの生物を殺してしまいます。
主には3つの理由だけれど、サーモンを養殖するという事は良い事ではない。サーモンを買うとき、本当にそれを買っていいのか考え直して欲しい。これが下記のヒューの文章です。(訳が下手な所、多少書き換えているところがありますが、そこは目をつぶってください・・・)
Written by Hugh. March 14, 2005
This evening, the professor of my environmental studies class finally came around to the lecture on aquaculture, his area of expertise, particularly the atlantic salmon aquaculture in British Columbia. (We are the fourth largest producer of Farmed Salmon in the world.)
For every one kilogram of salmon it requires 3 kilograms of animal feed input.
This input comes almost exculsively from Chile and Peru where they are very unsustainably harvesting their fish stocks (anchovy, smelt, and other small fish), the latest estimates say that these fisheries will collapse sometime in the next 8 years. This will leave thousands of South American fishermen without jobs and the BC aquaculture industry needing to find some other area of the world to exploit.
When the anchovy and other small fish are caught they are rendered down so that only the fat, oils, and protein remain, the rest is discarded as waste product. This is very high quality fish food, it also happens to be where all the PCBs and Dioxins are stored in the body of the fish, because of this diet, farmed fish contain approximately 10 times the toxic and carcinogenic chemicals that their wild counterparts do.
This feed then needs to be shipped to British Columbia, all of the transport involved means using a lot of energy. It is estimated that each 200g fillet of farmed salmon requires the energy of about 4L of burned diesel fuel to produce.
The farmed fish are then fed this unsustainably produced feed in very cramped conditions, requiring the heavy use of anti-biotics which has been shown to create conditions for the evolution of "super bugs" and also creating a sea lice problem.
A similar problem that BC is having with sea lice occured in the 1980s in Norway, where a parasite started attacking all of their salmon, farmed and wild, to get rid of it, they were forced to STERILIZE 27 rivers. Killing everything in them, and then restocking them with salmon from other parts of the country and the world, as you can imagine, there isn't much biodiversity that has returned to the rivers.
In British Columbia we now have these little sea lice that are infesting the farmed and wild populations. Normally the parasites are not a problem because when they attach to a salmon and create eggs, the eggs fall of into the water and need to find a new host in 3 days or they die, it doens't happen that often. With the Salmon Farms however, its obviously a huge problem because of the cramped conditions. Because the farms are often placed at the mouths of spawning rivers and protected areas they are infesting all the new little salmon and killing them, over the next couple of years this could have a devastating effect on wild populations.
And, if you are concerned about biodiversity, three of the graduate students of my prof have been doing a study of "wild" atlantic salmon, salmon that has escaped from the pens and managed to reproduce. The companies say that the populations are negligible and shouldn't be considered in the arguments for or against farmed salmon. His students have discovered that in the three spawning rivers they have studied on Vancouver Island, representing 0.001% of spawning habitat on the coast, all of them contain signifigant populations of "wild" atlantic salmon. Uh-oh.
And finally, because farmed salmon do not get the same amounts of red coloured shell fish in their diet, their flesh is not the same colour as wild salmon, so they dye it. They dye it with a chemical that has been connected to damage of the human retina. The EU has changed their regulations so that salmon farmers must reduce the amount of this chemical in the fish by 2/3. No moves have been made to do this in Canada.
Pick any of the above reasons ( I think they're all good ones) but please think twice about buying farmed salmon next time you go to grocery store or a restaurant (and most of the salmon in restaurants IS farmed salmon.)