Carl Safina is a fanatic fisherman. He's especially fanatic about ocean fish, which got him interested in seabirds, which got him into serious biology, which got him infuriated about what he was seeing in the fisheries, which got him to found the Audubon Society's Living Oceans Program.All of which got him to write Song for the Blue Ocean, a gripping book, believe it or not, about fish. Safina takes you out in the boats with commercial fleets. He takes you to Tokyo's Tsukiji fish market, where a large fraction of the world's catch ends up. He takes you to national and international meetings, where your jaw drops at the utter ineptness of fishing regulatory bodies. Best of all, Safina takes you into the astounding life of the fish, especially his favorite, the giant bluefin tuna.The bluefin is a muscular torpedo of a fish. It can sprint at 50 miles an hour and migrate thousands of miles. Full-grown ones reach 1200 pounds, though there are probably none left that big. They don't begin to breed until they get to 300 pounds. Most are caught before they reach breeding size, a practice which, everyone knows, dooms a fishery.Everyone knows, but it's happening anyway, because even a 200-pound juvenile, even a 60-pound baby, is a big, valuable fish. Safina says a bluefin can sell at the dock for more than $50 a pound. In Tokyo "one bluefin tuna recently sold for $83,500. The 715-pound giant was to be reduced to 2,400 servings of sushi, for $75 per serving, bringing in an estimated $180,000. One fish."A few quotes from Safina's book pretty much sum up the problem of the bluefin fishery.Charlie Horton, professional fish spotter (from a small plane) for commercial boats: "The truth is, the fish guys have done a lousy job. I mean, a really LOUSY job. So I'll support anybody that'll save these resources. It's possible we could wipe the fish out, just like it's possible to wipe out any species."Roger Hillhouse, another fish spotter: "We're not seeing any big, major year classes. We are not seeing the babies -- we are not seeing the spawning."Ed Miller, Montauk marina owner: "What's surprising about the bluefin tuna fishing is how fast the big fish have declined around here.... I don't know if it's overfishing or natural, or some combination, but it sure has gone downhill fast."Steve Weiner, East Coast Tuna Association: "If other people cared as much about their fisheries as we do about ours, we'd have very healthy fisheries worldwide. The bluefin regulations are working and the fish are coming back."Gerry Abrams, fish dealer, founder of the East Coast Tuna Association: "I don't buy the argument that man is the thing that is expendable in the quest to correct whatever is wrong. If we're going to err, we ought to err on the side of employment.... The bluefin is not a legitimate conservation issue, because the resource is not threatened. Abundance is tremendous."In 1981 scientists advising ICCAT (International Commission for the Conservation of Atlantic Tuna -- Safina calls it the International Conspiracy to Catch All the Tuna) warned that the bluefin population was depleted and the catch should be reduced to zero, which it wasn't. In 1990 the scientists estimated that the breeding stock had declined 90 percent and that the ICCAT quota (2660 metric tons per year) would continue the decline. ICCAT has not cut the quota, nor even enforced it strictly.Alex Adler, Cape Cod fisherman: "Where we now see five to twelve fish in pods, in the past the schools were frequently sixty to eighty fish, and I'd often see schools of two hundred to four hundred fish. It's great to have a shot a catching a fish worth ten grand, but they're worth so much money now, these guys will take the last buffalo. It's a sad deal. Deep down, I know the bluefin is in danger."Frank Mather, tuna researcher: "When the seiners started, they were catching young fish. They'd get a hundred tons of ten-pound fish, about twenty thousand young bluefins.... they were catching almost everything they saw.... A lot of fish were wasted because if a boat netted a hundred-ton school and only had room left on board for ten tons they would just drop the rest, which were already dead.... Now they say the breeders are down ninety percent ..., but the young fish were already creamed in 1970."Japanese ICCAT delegate: "This year we are pleased to see the stock has been showing a stable trend." (The scientific report actually showed a 20 percent drop.) "Current catch limits should result in increases in the population within five years." (The report said the population will decline further unless the catch is halved.) "We see no reason for further catch reductions."U.S. ICCAT delegate: "I've been coming here since 1983, and nothing -- EVER -- happens. Nothing. Nothing. Nothing!"Crashed populations of bluefin, cod, haddock, swordfish, are now costing New England fisheries $350 million in potential revenue annually and more than fourteen thousand jobs. Former fishing towns in New England and eastern Canada are experiencing 60 percent unemployment and a welfare burden of $2 billion. The U.S. as a whole is losing three hundred thousand jobs and $8 billion a year from depleted fisheries.Ron Bulmer, Fisheries Council of Canada: "The cod crisis has taught us a valuable lesson that others are going to have to learn, that we must err on the side of conservation."(Donella H. Meadows is director of the Sustainability Institute and an adjunct professor of environmental studies at Dartmouth College.)