Soy and polychaetes are bring used in a big way now for AC feeds. Soy more so and for longer. Companies like Dragon Feeds and Aqua Thrive are pushing the polychaete feeds w/ sustainable fish meal (fish meal scraps from processing plants doing food meant for human consumption)
Yeah scraps used to produce fishmeal are an imporatant resource. By-Catch resources are extremely under utilized and are one of many approaches toward making aquaculture more "green."
From Aquaculture Magazine Jan-Feb 2008 by Ronald W. Hardy:
"Landings of fish to produce fish meal and oil ranged between 28 mmt (million metric tons) and 32 mmt over the past 20 years. Currently about 50% of the annual production of fish meal and 85% or more of fish oil are used to produce aquafeeds. The rest is used in feeds for poultry, swine, cattle, pet foods"
He goes on to add:
"New (1996) estimates that seafood processing wastes and by-catch amounted to the almost 90% of the landed weight of fish harvested to produce fish meal. Globally, processing by-products and by-catch together are estimated to be 25-30 mmt, more or less equivalent to the average volume of landings used to produce fish meal and oil. Thus, if all fisheries by-product and by-catch were used to produce fish meal and oil, annual global production of each would double."
"In 2002, an estimated 5.6 mmt of processing by-products from food fish, were converted into fish meal and oil. This means that only 20% or so of all available by-product material was recovered and utilized."
He goes on to explain gastro-intestinal problems associated with fish meals produced wholly from bone source by-product.
None-the-less there are alot of valuable resources out there that we are missing out on. Not to mention soy proteins that can be added to this by-catch fish meal to create a wholesome feed for aquacultured fish.
Fish farming......especially tuna in sea-pens.....and the term "green" just don't go together.
With all this in mind I respectfully disagree.
Look up the environmental controversy surrounding shrimp culture and salmon culture.....watch out!!!!
There are real problems facing salmon culture, this is primarily a problem of parasitism, viral infections and use and overuse of antibiotics. However if mandated these problems can be mitigated with new technologies.
It would be really cool to see, but as a commercial operation for fish meat it would be a horrible idea. When it comes to fish, if it isn't wild caught, don't eat it. Farmed fish are an environmental disaster and they aren't worth eating.
While this is a horrible reality of poorly managed aquaculture projects (especially in developing countries), I think your over looking the problematic environmental and social issues associated with COMMERCIAL FISHING. Huge corporate fleets utilize; helicopters, planes, sonar, and giant trawlers to decimate wild populations. The truth is that wild fisheries stocks are poorly managed and many if not most are being fished to extinction. This is primarily because of inadequate enforcement of laws on quotas and techniques, the same could be true of farmed stocks if the infrastructure is not developed properly to oversee and mitigate the problems associated with the industry. But your statement vastly ignores the equally major concerns associated with wild populations.
I have to agree with this. On top of being an environmental disaster, the farm raised species also tend to have higher levels of toxins(biomagnification with added levels in a controlled area.) Ive seen pictures of areas down stream(so to speak) of shrimp farms where the wildlife dies off from all the excess nutrients.
Open ocean aquaculture is opening a lot of new opportunities for the industry. Companies like Kona Blue are prime examples of how excess nutrients in open ocean fishery pens can mitigate the large amount of wastes produced by farmed populations, and how aquaculture can be done in a "green" and sustainable manner. Biomagnification is primarily a concern with POP's (persistent organic pollutants) (aldrin, chlordane, DDT, dieldrin, endrin, heptachlor, hexachlorobenzene, mirex, polychlorinated biphenyls, polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans, and toxaphene.), antibiotics, and heavy metals.
Aquaculture is probably the only way that we will be able to feed the world in the future.
-Andy Long
I work with some one that used to work at Kona Blue 
We need to have a better regulatory branch to make sure our beer population doesn't get depleted!!! Riots surely would follow any beer shortage!!!
