Those super salmon ain’t so tough out in the wild
By Thoreau
Good news for those who fear genetically modified food: A strain of “super salmon”, that can grow to be more than 20 times larger than their wild counterparts, only achieve their super growth in the conditions of a “fish farm.” In a special cage designed to mimic the wild they are typically about twice as large as their non-modified counterparts.
The fear was that if these salmon escaped the farm and went into the wild they might create an ecological disaster by out-competing their wild counter-parts and then over-eating. These sorts of fears have delayed the mass production of such fish.
Now, admittedly, a fish twice as large is still worrisome from that perspective but (1) the dangers are apparently far smaller than initially believed and (2) even this test was done in artificial conditions. Of course, point (2) is a double-edged sword, but if the fish are really spoiled by being in cages, then there’s at least hope that engineered salmon will not fare terribly well in the wild.
If, by chance, the salmon do escape, I give my solemn vow to eat each and every one of them before they wreak havoc. It’s a tough job, but somebody’s got to do it.
Comment by Barry —
February 27, 2007 @ 8:46 pm
Jim, save some dill and sauce for me; I wouldn’t feel right if I left you to face that alone. I’d have a terribly empty feeling inside
Comment by Thoreau —
February 27, 2007 @ 11:33 pm
Actually, Barry, I’m the one who volunteered for the duty of dealing with super-sized salmon that escape, but I’m sure Jim would help us too.
Dill and sauce might not be enough. We might also need some almond crust. Or some soy sauce and ginger.
Comment by Jim Henley —
February 27, 2007 @ 11:45 pm
Will they hit a nymph is the real question.
Comment by josephdietrich —
February 28, 2007 @ 1:32 am
Giant Salmon vs. Asian Carp: FIGHT!
Comment by Doug T —
February 28, 2007 @ 9:32 am
I just hope that, if I run across a school of gigantic mutant salmon in the wild, the crew of the Calico are around to summon Godzilla to battle them for me.
Up from the depths
30 stories high…
Comment by diana —
February 28, 2007 @ 1:26 pm
Maybe I am totally misunderstanding the laws of natural selection but….
Only those genes that conferred an advantage in survival would survive to the next generation.
They cannot “outcompete” their wild cousins, by definition. That’s not a concept that makes sense, according to the laws of evolution. They are either superior in terms of fitness, or they are not.
So this issue strikes me a red herring. (Sorry.)
Comment by Barry —
February 28, 2007 @ 4:18 pm
diana, it does - if they can better exploit the same food sources, and better avoid the same predators (without getting eaten by bigger ones), they are outcompeting the wild salmon. The wild salmon would then suffer from food shortages, while predation stayed the same or increased.
Of course, since salmon presumably could have grown much large than they do, the supersize shouldn’t be much of an advantage.
Comment by Madeline F —
February 28, 2007 @ 8:11 pm
No, diana’s right, here. They’re the same species. They couldn’t “outcompete” each other. Maybe smaller salmon would die out over time, but their genes would continue, because their gametes would have mixed with mega-salmon gametes.
This is the salmon version of the X-Men.
Thoreau: put a byline on your (splendid, amazing) posts (so that we can properly honor them)!
(Almond crust? Sounds intriguing…)
Comment by Thoreau —
February 28, 2007 @ 9:46 pm
diana-
Are you saying that the wild salmon (without the genetic modification) must by definition have the advantage, because if bigger was better they’d already be bigger? If so, I have to disagree. Evolutionary theory says that over time favorable mutations will be retained, but it doesn’t say that all possible mutations have already been tried. It could be that a human-induced genetic modification is better than anything nature has tried so far.
Not saying it is that way (when in doubt, you should always bet that something that works great in the lab will fail in the field), but we can’t just assume that evolution has already optimized a species. Natural selection acting on random mutation will tend to preserve the best mutations that have arisen thus far, provided that they were the “best” in the context of the situation in which they arose, but that doesn’t mean that ever single configuration has already been tried and thus anything produced in the lab is disadvantageous.
Madeline-
Um, I did put a byline on this post.
As far as almond crust, it works really well on baked salmon. Best served with garlic mashed potatoes and carrots cooked with herbs.
Comment by Madeline F —
March 1, 2007 @ 1:28 pm
Geez, I’m a fool. I saw that right after I posted. I’m sorry.
I’m also imagining an almond roca crust on a salmon. Hmm… Sounds like something the Japanese would try.
Comment by diana —
March 1, 2007 @ 9:42 pm
“Are you saying that the wild salmon (without the genetic modification) must by definition have the advantage, because if bigger was better they’d already be bigger?”
The salmon have adapted to their environment. If the conditions favored larger salmon, they would have evolved. I’m not an expert on salmon feeding habits but if the wild salmon typically grow to X pounds, it’s because that is the optimal size in relation to the available calories.
Let me give you an analogy: feral cat colonies. Why do feral cat colonies, after say, 10 generations of breeding, not become the size of mountain lions? Doesn’t it sound logical that bigger is better?
Not necessarily. Cats pass on genes that confer fitness — and passing on genes for big size do not necessarily confer an advantage in fitness when calories are scarce.
“If so, I have to disagree. Evolutionary theory says that over time favorable mutations will be retained, but it doesn’t say that all possible mutations have already been tried.”
Right. But what makes you think this (biggie salmon) *hasn’t* been tried?
“Diana, it does - if they can better exploit the same food sources,”
In this case, big size means that they might overexploit the same food sources.
Notice I say “might”, not “would.” I’m not taking sides here.
” but we can’t just assume that evolution has already optimized a species.”
This means nothing scientifically. Evolution doesn’t “optimize” — it just selects; and if it didn’t select for giant sized salmons then there is a reason for it.
Comment by diana —
March 1, 2007 @ 9:45 pm
PS I would be more frightened that farm-raised salmon would introduce pathogens to wild populations that they have not developed immunities to. Look at the honeybee pop’n. We don’t know what’s killing them but I suspect it’s viruses spreading in crowded conditions.
It’s not nice to cross Mother Nature.