Rise of tuna farms fishy, at best
By all metrics, the bluefin tuna industry is in a state of paralysis. In the western Atlantic, the bluefin population is less than 10 percent of what it was 40 years ago, and American fishermen no longer worry about ever exceeding their fishing quotas of this sushi delicacy. As we wrote last week, the industry body that regulates tuna can’t sharpen its teeth enough to impose any useful restrictions.
That’s where farming enters the picture. The prospect of farmed tuna—with baby tunas born in a lab and then transferred to an aquatic pen—is heralded as the shock absorber that wild populations desperately need. Humans could finally evolve from hunters to ranchers of this finicky species, with fishermen rearing enough fleshy goldmines to satisfy every last table in Tokyo. In 2007, aquaculture supplied just less than half of the fish consumed worldwide, and that figure is expected to exceed the wild-caught numbers in the very near future. But breeding tuna has proved to be a greater challenge than any other fish. Until now, perhaps.
Last month, a group of European researchers coaxed caged bluefins in the Mediterranean into spawning millions of fertilized eggs. The scientists say that this was the first time that large quantities of viable bluefin eggs had been bred in captivity.
And in Australia, a fishing mogul just announced he had 50 million fertilized eggs and larvae, which his company, Clean Seas, rescued from its tanks to prevent the adult bluefin from dining on their young. (fellow T/S blogger Nadia Arumugam has more, from the foodie’s angle.)
Part of the challenge has been that tunas are sort of like the pandas of the sea, prone to turning up their snouts at romantic forays in the cage. Where pandas have been shown panda porn to get them to procreate, scientists found luck shooting darts full of hormones at the captive fish.
But excitement about tuna farming comes at an awkward time. Chile’s salmon stocks are still struggling to recover from the virus that decimated their numbers a year and a half ago. Known as infectious salmon anemia, the virus continues to threaten big fish farms around the world. Chile’s industry relied heavily on antibiotics to combat the virus, which originated in Norway. That choice has served to amplify the strain’s virility. Now the odd farm escapee can swim off into the great blue yonder, ready to infect wild fish and spread the problem.
In future posts, I’ll be investigating the globalization of marine ecosystems and the fishing industry. In the map I posted above, the yellow and red areas indicate invasive marine species hotspots. As you might expect, those zones are also home to the biggest fisheries, the worst pollution, and major shipping routes. Marine populations are mixing in profound new ways that have implications for the dining room table and the health of the world’s oceans.
Posted by Sandra Upson
Image credit: Hugo Ahlenius, UNEP/GRID-Arendal
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This is an interesting idea, and a good post, but a few things are missing. In some kinds of farming, there are sustainability issues, entirely different from wild-caught.
Feed to meat ratio-This will become an even larger issue with apex predators like tuna. Big tuna are the ocean equivilent of bears, but without all the screaming and gore. They too require a fair amount of food, and I’m thinking that tuna might be able to set a new bar for wasteful feeding for the amount of meat gained.
Another consideration are the farming methods. Some are very clean (US pond farming), and some are disgustingly dirty. (Salmon farming in most countries). This will be interesting to watch, and see where tuna farming goes.
You make a valid point – I didn’t go into the feed question in this post. In March, the UN Food and Agriculture Organization called for a doubling of aquaculture and emphasized that consumers should “eat vegetarian” when they choose their type of fish, in response to concern about the over-consumption of anchovies, sardines, and so forth in fish farming. I’ve also come across some efforts to develop a wheat-based alternative for tunas, but I’m skeptical. I’ll keep this in mind for a future post! -Sandra
[...] In a story mentioned in yesterday’s post, on the dawn of tuna farming: A fisher(y) king in Australia, having crippled the tuna stock that made his fortune, decides to [...]
Sandra, I’m glad you brought up the point about virus and disease afflicting fish farms that hoard thousands of fish in a relatively small space. Only in March of this year the Shetland Islands’ fish farming industry was threatened after the infectious salmon anaemia was confirmed in the third salmon farm. I keep coming upon similar stories that really makes me question the utility and safety of this industry.
Here’s a piece form The Observer on the Shetland story if you’re interested:
http://www.guardian.co.uk/uk/2009/mar/22/shetland-salmon-farms-virus
I am looking forward to following these postings for some time. A few years ago I gave up eating almost all seafood (except on rare special occasions, and not usually by my choice) after learning about the dire state of fisheries. Sushi and shellfish are my weaknesses. I keep hoping the news gets better, and I will be interested to see if there is any real good news about aquaculture. Also — thanks for the great multi-blogging, hive concept. I’ll be following to see how you take on other topics and where your conversations go.
[...] about the egregious overfishing of bluefin — possibly with mafia participation — and the difficulty of farming the extremely valuable fish from the egg up. According to a recent WWF analysis, if overfishing [...]
[...] Waiting for the Macaws • Get that fish off my helipad! Or, How Not To Save an Ecosystem • Rise of tuna farms fishy, at best • Is the Mafia stealing your tuna? • Putting a Price on Salmon • Fish by numbers • Farmed [...]