Put simply, we cannot feed the projected population of 12 billion people (by 2050) on beef. Hell, we probably can't do it on pork. That leaves chicken and various forms of fish. Chicken are much better at our favourite form of alchemy - turning vegetable in to meat - than beef, and most fish are better still than chickens. Were we willing to plan our diets rationally (no evidence of this, based on North American consumption) we would almost certainly choose to get our proteins from fish.
Unfortunately, the way we get fish is pretty horrible too. Forget the wild stuff - it's almost gone anyway. No, the growth industry for fish is the marine equivalent of ranching. Unfortunately, farmed salmon regularly tests much, much higher for pleasant little additives like PCBs.
(As an aside, you really have to admire western ingenuity. The Chinese and Indians have had a tradition of sustainable aquaculture going back millenia. We turn our aquaculture in to a toxic waste site.)
So what to do. Well, in this month's edition of Popular Science, it looks like the latest idea is open-ocean fish farms. Basically, the problem with fish farming as it's practiced conventionally is one of space - too many fish confined in too little volume. This is because relatively few places have the calm surface waters needed to build fish farms. So the few good spots are terribly crowded. This leads to intolerable pollution of the hydrosphere.
Solution: the ocean floor! There's plenty of room, and the rent is cheap. (Yes, rent. National governments get to lease out chunks of their exclusive economic zones, which extend from 3-200 miles from the shoreline.) Specifically, one company called Net Systems has been selling an underwater fish pen for years now. The pens are really very simple - a ballast tank sinks them to a depth where they don't endager shipping, and the waters are relatively calm. The outer net is made from military-grade plastic, both to keep the fish in and the sharks out. The next model - the 5400 - is also being designed with an automatic food hopper and remote maintenance abilities. The potential is pretty huge:
In 1999 the state of Hawaii granted Cates International permits to set up operation in state waters, and the company became the first private OOA outfit to start production in the U.S. Randy Cates currently sells 8,000 pounds of moi a week, but with plans in the works for a total of 16 cages and a new hatchery already going up, he expects to be selling four million pounds of the fish annually within two years—more than the total caught in Hawaii over the past half-century.Some interesting problems remain, of course. The biggest is that we tend to like carnivorous fish for dinner - Salmon, Tuna, Halibut, Cod all need to be fed protein, which has traditionally meant scooping vast amounts of wild catch out of the sea and turning those fish in to fish food. However, there is hope here. First, Cates and other early entrants in to the market seem to realize there's a branding opportunity here, and are making efforts to actually be sustainable (as opposed to simply looking sustainable.) This has meant a great deal of experimentation with feeding - including using soy as a feedstock to partially replace fish meal. In the future, your tuna will be fed tofu.
If Futurama taught us anything, however, it's that you can't feed a carnivore exclusively on tofu. So where there's a necessity for actual meat, it should be possible to replace wild catch with farmed feedstock. Given that Wal-Mart (!) wants certified sustainable fisheries for its stores, there's a real market here.
Option #2 is to simply not eat carnivorous fish, but instead eat carp or tilapia. Probably a non-starter.
The other problem is that many advocates for open ocean aquaculture seem to think - like we all did, back in the 1950s - that the solution to pollution is dilution. That is, if all that fish crap is being dumped in to a body the size of the pacific, it doesn't matter. I want to see independent measurements and data from some fish farms before I sign on. Factory hog farms have shown us that, above a certain density, animal wastes can be incredibly toxic.
Still, there's a lot of space out there, so at least initially there shouldn't be the same pressures to cram fish in so densely - the American EEZ actually encompasses more area than the lower 48 states. Meanwhile, beyond the EEZs are international waters, the last real wild west. I can't wait until we start reading stories of gun-slinging salmon rustlers, or mavericks who refuse to brand their halibut.
And to bring it back to energy (because I always do) even if these installations become more complex and industrialized, it should be possible to power them renewably, using ocean currents (analogous to windmills, but underwater) or the thermal difference between the warm surface of the ocean and the cold depths.
The problem with everything I write about the future, as always, is the difference what "can happen" and what "will happen." And as far as open ocean aquaculture goes, the inital signs aren't encouraging - the Bush administration is pushing legislation that would give the Commerce Department the regulatory oversight of offshore fish ranches. This is expected to mean little to no environmental regulation.
Some interesting links:
The Popular Science article itself.
A piece from the Seattle Post-Intelligencer.
An earlier Wired piece.
The University of New Hampshire's site on OOA. Some interesting info there.
Finally, a group that is very critical of OOA, the Institute for Agricultural and Trade Policy. Specifically, here. (PDF) Where they lose my vote is opposing OOA because it will harm fishing jobs. Sorry, when fewer people produce more food, that's called a good thing. Farming put the hunter-gatherers out of work, fish farming should do the same.