Quote: Originally Posted by Trex
I somewhat agree.
However fish farms have not as yet adapted farmed salmon to a vegetable based feed.
Every year the diet formulations are getting better. I attended a seminar with a nutritionist working in Norway last year, and the company he works for has a goal of zero marine protein and fatty acid. They've already completed phase one, and are partway through phase two. Phase three will bring it to zero.
This is partly out of necessity, and partly due to marketing. The aim for their company is a salmon that still has a good mix of EHA and DPA fatty acids, with less of the bioaccumulated toxins. A double whammy for health benefits.
As a result fishing fleets are strip-mining the southern oceans of herring and anchovy type species.
The bait fish landed hasn't increased at all over the years that aquaculture has grown. They were being strip mined before, for human nutritional supplements, for pharmaceuticals, for animal feeds, for fishing bait...it's insane.
These small fish are processed into a ground feed source for the fish farms.
On a by-weight basis it takes roughly 4 times the volume of the feed fish to raise a salmon.
And for wild salmon, it is about 15 kg needed to produce 1 kg of Oncorhynchus
salmonids. Alot is made of that number, but as I've said, every year it gets smaller and smaller. It has to out of necessity. The capture fishery for fish meal is stagnant, and the demand grows every year.
On top of that the anchovy and herring species are more appropriate (from a health perspective) as a human food source than the salmon. This is because heavy metals and carcinogenics tend to increase and become more concentrated as you move up the food chain.
As I said, that is becoming less of an issue all the time. The pcb's in a serving of farmed salmon are lower than in a glass of milk, for some context, and lower than those in Chinook salmon
Thus those smaller fish would actually be a better food source.
To be realistic, salmon isn't in the same category as herring or anchovies.
Also that Slice stuff they use to treat the sea lice is really toxic and nasty.
Yeah, that's what the 68 day withdrawal period is for. This will also be a problem of the past shortly. Turns out that sea lice resistant is a highly heritable trait (anything with a heirtability score above 0.3 is highly heritable). Breeding programs are now utilizing this.
Also they add a carotene like dye to the salmon feed. If they didn't the farmed salmon tend to have a visually unappealing grey flesh.
The topic of my fourth year project last year! It reduces the severity and duration of the stress response in rainbow trout. Astaxanthin is a naturally occurring pigment.
I refuse to eat farmed salmon myself.
To each his own