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Tuna born from mackerel: Japanese scientists develop surrogate tech to save threatened species

18 Comments
By RocketNews24

Last November, the sushi world was struck with some bitter news: the Pacific bluefin tuna was placed on the International Union for Conservation of Nature and Natural Resources’ (IUCN) Red List of Threatened Species. While not considered endangered like its close relatives, the Atlantic and Southern bluefin tuna, it has been proclaimed as a vulnerable species.

Bluefin tuna is considered the best of the best, its tender red meat is coveted by sushi chefs and sushi consumers alike. But what will happen if the Pacific bluefin becomes extinct? Foreseeing a future of sushi connoisseurs being forced to eat tuna-shaped cakes or playing with tuna models to try to get their bluefin fix, scientists have come up with a radical new idea: use mackerel to breed bluefin tuna.

f you’ve ever eaten high-quality sushi, there is a good chance you’ve tasted some bluefin tuna. In fact, U.S. President Barack Obama faced some flak from Greenpeace after dining at Sukiyabashi Jiro (the restaurant featured in the documentary "Jiro Dreams of Sushi") with Japanese Prime Minister Abe. They ate the “special course,” which usually features the famed, but vulnerable, bluefin tuna, much to the displeasure of Greenpeace.

It’s clear that people love to eat bluefin, but apparently they love it a little too much, since overfishing has been a significant factor in the near demise of the species. So what can we do?

While stopping all consumption would be ideal, it might not be enough. Scientists at universities, including Kinki University, have been trying to farm tuna for years, but with little success. One main problem is that tuna take up to five years to mature into the breeding stage of their life-cycle. That’s a pretty long time in the animal world. Not to mention that a full-grown tuna weighs up to 100 kg, and to gain one kilogram they have to eat 20-40 kg of food. Needless to say, they aren’t the easiest guys to take care of. Then there is the problem of the fish being kind of dull in the head, and often killing themselves by ramming into the walls of the tanks, only to be eaten by their cannibalistic brethren.

Tokyo University of Marine Science and Technology fish specialist Goro Yoshizaki has come up with a new, outrageous sounding plan. After years of research with other fish, he will start using mackerel as surrogate parents for bluefin tuna.

It gets kind of technical, so let’s keep it simple. The basic idea is that the scientists will take baby mackerel and inject their reproductive organs with the reproductive cells of the bluefin tuna. As the mackerel mature, the females will produce tuna eggs and the males will produce tuna sperm, instead of mackerel eggs and mackerel sperm. Then, after the normal reproductive affair, little tuna will be born.

But what’s the advantage of using mackerel? Well, let me tell you! First of all, mackerel aren’t endangered. Better yet, they mature into the reproductive stage within only one year, meaning baby tuna will be born at a rate five-times faster than if we relied on the tuna to make their own babies. Then there is also the benefit of mackerel being significantly smaller (300 grams), so they are easier to keep in tanks, instead of the open-water reserves that tuna need. Plus, they don’t require as much food, so they are also much cheaper to feed.

Another reason they chose mackerel over other fish, is that mackerel, tuna and bonito are actually all from the same family and sub-family, Scombridae, meaning they have similar DNA, but you would never guess it based on how they taste.

While this research seems really promising, it’s going to be quite some time until it’s put into serious action. This summer they plan on starting the first phase of research, but it could be up to ten years before it makes it to the commercial level. The big question now is: How do the mackerel feel about this? In nature, bluefin tuna prey on mackerel, so in a sense, the mackerel are birthing their sworn enemies.

Source: Naver Matome

Read more stories from RocketNews24. -- Japan’s Top Five Favorite Sushi Toppings -- Greenpeace tells Obama to make ‘more responsible’ food choices after meal at restaurant that serves endangered sushi -- Japanese couple celebrates wedding with cake shaped like a sliced-up, possibly bloody tuna

© Japan Today

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18 Comments
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Will it taste the same?

0 ( +2 / -2 )

But what’s the advantage of using mackerel? Well, let me tell you! First of all, mackerel aren’t endangered. Better yet, they mature into the reproductive stage within only one year, meaning baby tuna will be born at a rate five-times faster than if we relied on the tuna to make their own babies. Then there is also the benefit of mackerel being significantly smaller (300 grams), so they are easier to keep in tanks, instead of the open-water reserves that tuna need. Plus, they don’t require as much food, so they are also much cheaper to feed.

So the solution to saving Blue Fin Tuna is to mutate it into something else, rather than using are common sense to protect these indangered species.

0 ( +5 / -5 )

Great news!

4 ( +7 / -3 )

Will these mackerel-born tuna have the same delicious mercury content of natural-born tuna? That's really important in keeping up the entirety of the tuna-eating culinary experience.

-3 ( +2 / -5 )

Wonder what genetics may result in being modified in such an endeavour?

If there's no other choice for bluefin tuna, would people not mind eating this?

0 ( +1 / -1 )

As is typical Japanese avoid the obvious STOP eating the tuna DUH!

I stopped about 7-8yrs ago, I am still surviving! When I first washed up on these isles tuna consumption was a treat, since the mid 90s the locals have been GORGING on the stuff, its quite common to see one person boff 3-4 plates of various maguro & then wonder why its becoming scarce!

Various tuna populations have been decimated around the world with most of the consumption happening in Japan, squid octopus,same, unagi, same, the pattern keeps getting repeated & we virtually NEVER hear the word:

CONSERVATION

Too difficult to understand I suppose.

-1 ( +3 / -4 )

'We're willing to try anything except the one thing we know that will definitely work.'

2 ( +3 / -1 )

Kinki University, have been trying to farm tuna for years, but with little success.

Talk about trash sensationalism. Kinki University ships 2,000 tonnes of complete farmed tuna a year and are expanding that yield in the following years by tying up with Nichiro.

2 ( +2 / -0 )

So they can bring a species back from the brink... and hunt them. You couldn't make it up.

0 ( +1 / -1 )

I think you're being unfair, @GW.

-1 ( +1 / -2 )

I think you're being unfair, @GW

Hardly! Japan has been a MASSIVE consumer of seafood for decades, its common knowledge. Doesn't matter who catches the stuff most ends up in Japan, been that way for ages now!

0 ( +1 / -1 )

If they tempered this with a cut down in consumption overall so that stocks could replenish themselves, that would be even better! But already I've heard people defend the depletion of bluefin tuna and not making attempts to reel it in with a sigh of relief that they can now farm tuna (although "it doesn't taste as good!").

-2 ( +2 / -4 )

Yeah, I gotta agree with other posts that the only way to preserve tuna is to stop consuming it. Many of the Japanese I know eat tuna four or five times a week with no regard what-so-ever to its endangered status. If these people were to cut their consumption back to three or four time a month it would make a huge difference. However, consumption is not the only problem. The main problem is overfishing, obviously. The tuna (and seafood in general) markets make up a large part of japanese commerce and economy. All these industries rely on the high rate of consumption to support their businesses. This genetic gimmick might seem like a step in the right direction, but there is no way they can breed enough bluefin tuna from mackerel to support the high demand. There is also the economic issue for fishermen losing their fishing quotas.

The only way for bluefin and many other tuna species will survive is if countries like Japan stop hunting them into extinction. Quotas were set up 30 odd years ago, but Japan has a long and documented history of abusing these quotas. If the overfishing was stopped the price would increase, which would in turn reduce the consumption. Sadly though, there seems to be an 'eat it while you can' mentality among Japanese.

-1 ( +1 / -2 )

In the US, the Chinese operated sushi buffets feature pseudo maguro (ahi, big-eye, or tilapia dyed red) sashimi and nigiri sushi. The taste and texture are obviously not tuna but, as typical of Americans, most don't know and don't care. So we can applaud American ignorance for their role in tuna conservation.

-2 ( +0 / -2 )

The word "conservation" doesn't exist in a japanese dictionary. So sad......

-1 ( +1 / -2 )

ZettaiEngineer

Ooh you are so edgy and cool! Where did you get that info, fake news daily?

3 ( +3 / -0 )

So it's not wholly mackerel?

0 ( +0 / -0 )

@ CoconutE3, clearly you haven't had to suffer the repercussions of "setsuden".

So much Japan bashing in the comments! It's not just Japan that likes to indulge in sushi. This is good news folks! IF they can pull it off. Fingers crossed! I love otoro.

0 ( +0 / -0 )

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