Four Fish Page 22
Today this kind of egregious dumping of mercury is rare, but mercury is still entering the environment on a regular basis from coal-fired power plants throughout the industrialized world. This happens when mercury deposits in coal seams are “methylated”—that is, fixed through combustion to carbon and hydrogen atoms—into a chemically “sticky” molecule called methyl mercury. Methyl mercury bonds readily to living tissue when introduced into the marine environment. As with PCBs, methyl mercury is first absorbed by plankton and then passed up the food chain to small forage fish, then to low-level predators like mackerel, and then finally on to apex predators like tuna. Again, as with PCBs, methyl mercury has a tendency to linger in animal tissues (though not nearly as long as PCBs). Therefore, as with PCBs, mercury concentrations amplify in fish at higher levels on the food chain. It is the biggest, longest-living fish that tend to have the most mercury, and in the ocean it is harder to find a bigger, longer-living fish than the bluefin tuna. Some U.S. consumers have backed away from eating bluefin. The “choice” of eating unpolluted fish versus polluted fish is another factor often included in safe-seafood lists compiled by American nonprofit organizations. But, curiously, Japan, the place that had the most extreme exposure to mercury poisoning, keeps eating big tuna with abandon.
It starts to feel as if the phase of “awareness enlightening” with big fish that Vikki Spruill spoke of, the phase in which consumers educate and, dare I say, edify themselves by choosing good fish over bad fish, needs to come to a close. For in the end, this somewhat passive response to the global crisis in fisheries robs the conservation movement of the will to stage more radical, directed, and passionate action. Daniel Pauly, the author of the shifting-baselines theory and frequent critic of the limited views of the sustainable seafood movement, said as much in a recent paper. “The current faith in the magic of free-market mechanisms must be questioned,” Pauly wrote. “Consumers should not be misled that a system of management or conservation based on purchasing power alone will adequately address the present dilemma facing fisheries globally.” Indeed, Pauly’s words turned out to be prescient even with the “saved” swordfish. Harpoon-caught North Atlantic swordfish is now listed as a “Best Choice” or “Good Alternative” on the Monterey Bay Aquarium’s seafood watch cards. But the National Marine Fisheries Services has relaxed fishing for those same swordfish where they breed in the gulf, and fishermen are now reporting severe declines in the stock. As Adam LaRosa, a charter boat operator who targets tuna and other big pelagic fish, told me, “These kinds of things don’t work, unless you do them forever.”
Meanwhile the bluefin catch continues, the fish decline. No one has yet motored a Greenpeace Zodiac between a school of breaching bluefin tuna and the boat that would haul them in to market. Whales have become wildlife. But tuna have remained food. The “seafood choices” wing of the ocean-conservation movement would ask people to hold a dual concept of the bluefin as both food and wildlife, but this doesn’t seem to be something humans can do. To most people an animal is either food or wildlife. If a fish ends up in the market, humans will come to the obvious conclusion that it is food; they will then choose to eat it, even if they are warned that the fish is endangered or contaminated with mercury. In the absence of a larger moral argument and more profound government action, the animal’s appearance as flesh in the market, unfortunately, argues more effectively than do any caveats against eating it.
One important element of the whale-conservation movement that the environmental victors seldom discuss is the fact that by the time the Greenpeace Zodiacs hit the waves, whales as objects of commerce had become more or less irrelevant. While Norwegians, Japanese, and Icelanders continued (and continue) to eat a few pounds of whale meat every year, the majority of humans, once their economies had recovered from the devastation of World War II, no longer needed whales. One of the driving forces behind the second era of whale hunting was the production of edible oils from whale fat for margarine and cooking. Throughout the sixties and seventies, though, there was an edible-oil revolution (that Green Revolution again). Developing nations were encouraged to produce palm, groundnut, peanut, and other agricultural oils locally. By the time of the 1982 moratorium, whale oil provided less than 1 percent of the world’s cooking-oil needs.
It is here perhaps that a parallel development with bluefin tuna needs to be pursued. If no one is willing to get into that damn Zodiac, then a replacement for bluefin must be found, something that would undermine a major component of the fish’s attractiveness. A domestic version of the fading wild animal.
But as we reach the last chapter of fish decoding, we are finally coming up against a fish that, while we like it a lot, may ultimately not make very much sense to farm. Tuna-ranching operations whereby wild young tuna are netted, transferred alive to pens, and fattened to adult sizes have been in existence for over a decade now; indeed, these operations today remove more tuna from the wild than do traditional fisheries. And now, with tuna ranching facing staunch environmental criticisms, a brave new world of fish domestication is nearing realization, one that owes its existence to the decoding of the European sea bass back in the 1960s and ’70s.
As I write this, the final steps of closing the life cycle of bluefin tuna have just occurred. A company called Clean Seas in Australia has created perfectly temperature- and light-controlled breeding tanks that have induced the first captive spawning of bluefins in history. The time-release GnRH hormone spheres developed for sea bass and sea bream by Yonathan Zohar (the Israeli self-described “ob-gyn for fish”) are shot into the tuna via a slender harpoon. Thanks to this technology, in July of 2009 the first large-scale captive spawning of tuna took place under a thick cloak of secrecy. Time magazine judged the achievement as the second most important invention of the year. Soon after the Time article, Zohar wrote me, deeply troubled, that he and all his work that had preceded this mile-stone got nary a mention in the Time article.
But beyond the spawning of tuna, there are considerable complications ahead. Because bluefin are warm-blooded and lightning-fast, they have furiously high metabolic rates. The microdiets of rotifers and artemia used with sea bass aren’t enrichable enough to satisfy tuna’s high-energy demands. Moreover, maintaining a family of five-hundred-pound tuna broodstock is extremely costly. So costly that some researchers are even exploring a bizarre hybridizing project whereby mature bluefin gonads are implanted in the body of a dramatically smaller fish called a bonito in order to turn these small fish into surrogate mothers. Taxonomically speaking, bonito are tuna, but they are less than ten pounds at maturity. It is a weird kind of package, but initial trials are showing some positive results.
However, whether bluefin tuna will artificially reproduce via bonito or via a precisely controlled artificial environment with Zoharian hormone spheres trickling through their bloodstreams, the fact remains that bluefin are warm-blooded, fast-swimming, highly complicated animals that in the best-case scenario will still require a tremendous amount of food to bring them to market. Whereas twenty generations of selective salmon breeding in Norway have brought the feed-conversion ratio in Atlantic salmon down below three pounds of feed to one pound of salmon, tuna still require as much as twenty pounds of feed for every pound of flesh they produce. This is considerably worse than all other fish. Perhaps a selective-breeding program might bring the conversion rate down around five to one, but this is still terrible.
So we have to ask ourselves, is bluefin tuna really so special that no substitute will do? Japanese defenders of the bluefin trade cite the long cultural tradition of tuna sushi in Japan. But as I wrote earlier, when you look at it in a historical context, the Japanese have a very short tradition of eating bluefin. Before the American occupation of Japan, Japanese preferred lean fish and meats and found the bluefin too fatty to stomach. It was only after the American occupation and the subsequent introduction of fatty beef into the Japanese diet that a taste for the fatty “toro” belly of bluefin started to become f
ashionable. If the Japanese adapted to a higher-fat diet in less than half a century, can we not shift gears again and adapt to a sustainable diet in the same period of time?
It was in answer to these questions that I set out trying to discover a truly thick-fleshed farmed fish that could fulfill the steaky category most seafood diners now expect to see on a menu. A fish that had the “bite” of tuna but might have a footprint more akin to that of a barramundi or a tilapia. And so I found myself in a dive boat, three miles off the coast of the big island of Hawaii, motoring across the cerulean blue of the South Pacific with a tall, highly optimistic Australian named Neil Sims. Rejoicing in telling me tales of his adopted land, Sims was flitting from topic to topic, bearing the relaxed but enthusiastic attitude of what Hawaiians call the “aloha spirit.” Eventually we neared the site of Sims’s farm—a huge underwater ziggurat that is the center of his company, Kona Blue.
It had been a long time since I’d scuba dived, and even when I’d first learned in college, my skills had been rudimentary at best. We were now about to embark on what is called in scuba a “blue-water dive”—a plunge into the open ocean, hovering over a depth of nearly three hundred feet of water. Because such a dive does not take place above a coral reef, a seawall, or any other structure, a blue-water dive is extremely scary. There are no perceivable reference points that allow the diver to determine depth. If the diver is, like me, inexperienced, he can freak out, lose his bearings, fail to establish neutral buoyancy with his buoyancy-compensator vest (a kind of external human swim bladder), and find himself sinking unstoppably. If this happens, the diver will surely die. Either he will be crushed like a tin can at the bottom or, because he sank so low that he did not have adequate oxygen to surface slowly and decompress, oxygen will boil out of his blood and block his veins and arteries when he dashes to the surface. I was busy trying to keep cool and not betray the fact that I was scared shitless.
This all crumpled when Sims patted me on the back, looked me in the eye, and said, “Got your wet suit on backwards, mate.”
In spite of my anxiety, I was curious to see what Sims was up to. He was, like Josh Goldman and his barramundi in Turners Falls, flying in the face of convention when it came to his selection of fish. Up until very recently, most of the fish that we’ve chosen for our consumption and domestication have been accidents. We have taken those species because we knew them as wild game and then found that they fit well into our culinary and economic niches. We seldom considered their biological profiles or whether they jibed well with conditions that humankind could provide them.
Norway selected Atlantic salmon as its target farmed fish because the demise of wild temperate-zone rivers around the Northern Hemisphere was a common plight. Most Americans or Europeans had a distant memory of wild salmon, but practically no one had access to a reliable supply of it. Farmed salmon reclaimed that lost memory.
Israelis chose to pursue the domestication of the European sea bass because it was known in nearly all countries of the Mediterranean and because it was so overfished that it fetched a high price.
Cod became the first global fish commodity, mainly because it took well to preserving—dried cod lasts for years and could be shipped around the globe even on the slowest of oceangoing vessels. But when farmed, cod is expensive and slow-growing—disastrous as an aquaculture product.
But Sims came to aquaculture through environmental zeal, not with the intention of making a buck. And it was his direct personal experience with the limitations of fisheries management that convinced him that fish farming was a better choice than fish catching.
Sims began his career in the remote Cook Islands of the South Pacific. There he was responsible for establishing a fishery-management regime for a kind of giant snail called a trochus that produces an attractive pearly shell, valuable to jewelry makers. Over the course of five years, he tried to implement a number of different approaches to get the Polynesian natives to conserve the trochus stocks, reminiscent of some of the many measures that have been taken with salmon, bass, cod, and tuna. He closed fishing seasons, planned reserve areas, established size limits, reduced individual quotas . Nothing worked. Finally, after trying numerous approaches, he, as the senior scientist, simply closed the entire fishery. The following day he came across a bare-chested Polynesian elder paddling a dugout canoe through the lagoons. Sims looked inside the hull and saw it filled with trochus snails, in spite of the closed season. “I yelled at him,” Sims remembers. “Then he yelled at me. He started to cry. Then I started to cry, and then the old bugger finally says, ‘Why? Why did you close the season? There are still some trochus left! We haven’t caught them all yet.’”
This led Sims to realize that we needed to do more than just regulate fisheries—we needed to work out a different methodology altogether.
A chain of events led him to Hawaii, but the primary draw was the opportunity to begin aquaculture in the clear, strong currents surrounding the town of Kailua Kona. At first he tried pearl farming, but when the pearl market became flooded with freshwater pearls, Sims began reexamining the possibility of returning to his passion—fish and fisheries biology. There were small government grants available for research into marine aquaculture. “People were trying out the Hawaiian fish called moi. It’s a niche species, really. And they were also trying milkfish and mullet.” None of these species, Sims felt, truly addressed the niche that needed to be filled by aquaculture—the niche of thick-fleshed predators such as tuna.
It was at this point that, like Josh Goldman and his barramundi, Sims decided to turn the equation of aquaculture on its head. Instead of finding a fish that people knew, that was scarce, and that had an established market, Sims wanted to find a fish that was right for aquaculture, whether or not it was known. To rationally and scientifically apply Galton’s principles of domestication and see if there was a fish that fit those criteria.
Eventually Sims came across a fish that previously had no market value whatsoever. Seriola rivoliana, known as the Almaco jack or the kahala in Hawaii, is a speedy, firm-fleshed blue-water species of the same family of fish as yellowtail and amberjack. Kahala are only distantly related to tuna and do not have their ruby-red color, but they still have the thick, dense flesh of tuna and could easily pass for white albacore if prepared as sushi.
Another important factor about kahala is that they were never fished commercially and are hence quite abundant. The reason for this is that in their wild form the fish can cause a disease in humans called ciguatera poisoning. Ciguatera is a poison created by microscopic organisms called dinoflagellates. The toxins in dinoflagellates enter the food chain like all the other toxins mentioned earlier—that is, from the bottom. Dinoflagellates stick to coral and are eaten by small fish. These small fish are then eaten by bigger fish. Just like mercury, ciguatera toxins generated from the dinoflagellates bioaccumulate in large predators like kahala making kahala flesh dangerous food for humans.
But when kahala are fed a traditional aquaculture diet and isolated from tropical reefs, the fish are ciguatera-free. And because the wild population of kahala is large and healthy, they are unlikely to be severely damaged through interaction with farmed populations. Moreover, of all marine fish currently farmed, kahala have among the best feed-conversion ratios ever achieved. Without any selective breeding whatsoever, the amount of fish required to produce a pound of kahala ranges from 1.6-to-1 to 2-to-1, ten times better than the feed conversion ratio for bluefin tuna. Feed trials scheduled to begin in summer 2010 will introduce pellets without any wild fish meal at all.
As for another of Galton’s principles, the one that stipulates that “they should breed freely,” kahala are equally appealing. When I asked Sims later if he uses any of Yonathan Zohar’s time-release polymer spheres or photoperiod manipulation to get the fish to spawn, he responded cheekily. “No, we do not use any hormones or environmental manipulation. We tried soft music and candlelight and a little wine, and it worked just as well without. So we
kept the wine for ourselves.” Kahala spawn constantly, sometimes weekly, throughout the year. They are, in short, the fish we should have chosen right from the start.
The problem is, as with the barramundi of Turners Falls, no one quite knows what they are. Neil Sims and a marketing team that included the main investor in Horizon organic milk have decided to call the fish “Kona Kampachi.” Kona for its point of origin and kampachi based on a similar fish that is consumed in Japan. A sushi chef in New York whom I later asked about the fish complained, “Well, you know, Kona Kampachi, that’s an artificial name. Kampachi is kampachi, and it is from Japan.”
But artificial name or not, the fish has real benefits and poses a real possibility for change. Diving into the waters around Kailua-Kona, watching Neil up ahead of me, I felt the sensation of a whole different world emerging before me. Using technology developed over the last ten years by the University of New Hampshire, Kona Blue has constructed diamond-shaped cages that can be moored in the open ocean. While powerful storms do happen off Kona and a rupture could occur in Sims’s nets, the fact that the fish Sims is using are not selectively bred limits the potential genetic impact the fish could have on the surrounding populations should they escape. As I glided down, down, down, past the beautiful fish swimming in unison in their net pen, I thought that for the first time I was seeing the ocean on a fish’s terms. The site of these pens had been painstakingly chosen; the swift, swirling currents mean that nutrients do not accumulate below the pens, and therefore the impact on the environment is minimal. Sims also constantly monitors his kahala for ecto-parasites like sea lice and has found their occurrence on his farm lower than on kahala in the wild. Down and down I drifted. From below I looked up at the cage, seeing how little it looked in relation to the bigness of the ocean.