Anyone who has seen one of my presentations or endured my presence on a panel has probably heard me lambaste bluefin tuna ranching. I often employ a hackneyed analogy to describe this phenomenon by equating ranching bluefin to “farming tigers.” The reasoning behind this has to do with the position that bluefin occupies in the oceanic food web. Bluefin tuna are top carnivores in the watery realms, and thus are similar to the great cats and other apex predators here on terra firma.
The point here is simple: we don’t farm great cats. Not just because they don’t taste good (although I can’t imagine that they do), but because it makes exactly zero sense from the perspective of an agriculturist. A tiger farmer would have to raise or purchase grass or grain to feed herbivores (such as cows), raise and fatten the cows, and then slaughter the cows to feed the tigers. The amount of salable protein generated by butchering the tigers would be only a fraction of what the farmer could realize by butchering and selling the cows (not to mention how much more efficient it would be to simply sell the grain itself for human consumption.)
There are two differences between a bluefin ranch and a theoretical tiger farm from a markets perspective. The first is demand. Aside from a peripheral black market, based primarily in China, that values the penis and gall bladder of the animal for pseudo-medicinal purposes, there is no demand for tiger flesh. Bluefin, unfortunately, is struggling under the weight of tremendous demand driven by a rapidly expanding sushi industry.
The second difference is the legal recognition (and a strong social awareness) of the animal’s plight. All of the world’s tiger subspecies are, lamentably, endangered at best. Ironically, the charisma of the tiger and the widespread awareness of its unenviable situation has earned it a tremendous amount of support in the form of global conservation effort. In fact, the tiger was voted the “world’s favorite animal” in a 2005 survey by Animal Planet (even defeating such lovable competitors as the dog and the dolphin.)
The bluefin tuna has no such succor. It is a migratory oceanic species and thus extremely difficult to protect through national legislation. International agreements such as ICCAT continue to fail to address the actual issues threatening the species (overfishing, bycatch, etc.) Moreover, while this animal is fascinating and extremely charismatic to those fortunate few who have interacted with it, the bluefin still suffers from the “it’s just a fish” veil of dismissal that keeps us at arm’s length from many of our ocean’s most awe-inspiring denizens.
The point of all this is to say that while we would never consider farming tigers as a protein source, we farm bluefin in great numbers, despite their relatively equivalent positions in their respective ecosystems. It’s an incredibly resource-intensive task to farm a bluefin. For every salable pound of tuna that comes out of a bluefin farm, up to twenty-five pounds of wild fish (often sardines and anchoveta from unmanaged fisheries) have gone in as feed. To make matters worse, bluefin are only very rarely reared ex ovo; traditionally, the juveniles are purloined from the wild and transferred to pens for fattening. Thus, every tuna that one purchases from a bluefun tuna farm is actually a wild tuna that never had an opportunity to breed. Needless to say, the world’s wild bluefin tuna populations are shadows of their former selves. The bluefin is, for all intents and purposes, an endangered species. Yet we continue to devour it without compunction.
Things seem bleak, indeed. And it is from this stark landscape that a new player has arisen, with a plan to ease the pressure.
Hawaii Oceanic Technology, a Honolulu-based company, is aiming to create a new tuna farm that instead of adding to the woes of the bluefin, will focus on one of it’s relatives: Thunnus obesus, the bigeye tuna. Ostensibly, this will lessen the overall pressure on bluefin by offering a similar fish to appease market demand.
While bluefin is generally fattened in inshore net pens, Hawaii Oceanic intends to construct an offshore farm, located about three miles off the coast of the Big Island of Hawaii. One of the potential advantages of offshore aquaculture is that it is thought to reduce the impact of waste by allowing effluent to diffuse through a much deeper water column. The revolutionary Kona Blue operation, similarly located in Hawaii, utilizes this principle in its production of Seriola rivioliana, which it markets as “Kona Kampachi.”
While there is still a pronounced paucity of evidence regarding this hypothesis, it seems to be based on reasonable assumptions, and I don’t want to dwell on it as I feel there are three other, more important issues at stake. Additionally, the prototype “Oceanspheres” that Hawaii Oceanic are developing for use as fish enclosures are really quite impressive — especially their use of OTEC (ocean thermal energy conversion) technology, which is a virtually untapped renewable energy resource. I’m very interested to see where this leads.
Anyhow, back to the issues at hand.
First off: market demand. Bigeye tuna, known as mebachi in Japanese, is indeed a source of tuna fillets, fatty belly cuts, etc. But to be frank, mebachi toro is simply not as alluring as honmaguro (bluefin) toro. As a matter of fact, the best replacement that I have found for the buttery, supple taste and texture of bluefin belly is high-quality shiromaguro toro – a belly cut from the albacore, bluefin’s much smaller cousin. I am not alone in my beliefs here. Sure, mebachi is still a much-demanded fish, but will it really affect the demand for bluefin?
The second issue is feed. As I mentioned before, farming bluefin is a protein-hungry business. Why would farming bigeye be any different? Hawaii Oceanic states that their goal is to eventually replace the fish used in the feed process with soy or an algae-based protein source, but that they will need to use fish meal at first.
Certainly one has to begin any new venture in stages… but how long are we talking about? There is no need for another fish-based tuna farm. There was never any environmental benefit to these operations in the first place. If indeed it were a farm fed entirely from sustainable sources, that would potentially change the equation — but there’s a big word between now and then, and that word is “eventually.” The lack of a hard timetable here casts some doubt on the rosy picture that Hawaii Oceanic has painted.
The final issue is the sourcing of the fish itself. One of the major problems with bluefin farms is that the fish are taken as juveniles from flagging wild stocks. Hawaii Oceanic pledges to surmount this obstacle by hatching bigeye from eggs in a controlled facility. These fry would then be transferred to the offshore pens for rearing.
This is a good plan, if it can be achieved. In essence, by allowing the company to breed tuna from a small clutch of broodstock rather than abducting wild fish, they can produce tuna without major detrimental impacts to the local populations (at least from a sourcing perspective.) But can they do it?
The A-Marine Kindai bluefin operation in Japan has managed to create a system where they hatch their fish in a similar manner. This type of aquaculture, known as “closed life cycle farming,” is certainly a step in the right direction. But is it missing the point?
Even if this kind of thing ends up working, we’re still dealing with an apex predator, and thus eating very high on the food chain. When trophic dynamics are considered, it becomes clear that the amount of energy demanded from natural (or, in this case, quasi-natural) cycles to produce something like a farmed tuna dwarfs the actual amount of protein received by the consumer. Farming this kind of animal is reinforcing a negative paradigm that has been held as gospel in the North American diet for far too long. Moreover, tuna do not have the fish oils and the omega-3s that many smaller, cold-water fish (such as mackerel and sardines) do, nor do they reproduce as quickly. Not to mention that this type of aquaculture is never going to “feed the world” — it’s simply too expensive.
While Hawaii Oceanic may be attempting to build a better mousetrap with this theoretical bigeye farm, we may be swapping tigers for lions. It we want a harmonious and sustainable relationship with the world’s oceans, it will take more than finding a way to create larger amounts of what the market currently demands. We need to be willing to significantly alter the way that we think about food, and I’m not sure how much of a change a bigeye farm really represents.