Scientists are tame bluefin tuna to get enough sushi ingredients

This method of aquaculture will give us an endless source of tuna to enjoy.

The atmosphere at the tuna farm is located in a small town along the coast of Mazzaron, in the absolutely quiet southeastern Spain. Not that this place does not work, but it must be. In the large water tank, 100 rugby-sized Atlantic bluefin tuna are trying to adapt to the 22-meter-wide, 10-meter-high water tank. If they were startled, they would be frightened and rush into the pool wall, break their spine.

When the bluefin tuna breed is still young, there are millions of dead in captivity for the above reason. But when they are more mature, the rate will decrease significantly. But on the fateful morning that Motherboard reporter visited the fish farming facility in Spain, he immediately met the case of a one-year-old fish hitting a concrete wall and dying.

"This is the first fish to die in the last 4 months , " said Fernando de la Gandara, the director of the fish breeding center, in a decisive voice, implying that there is nothing to worry about.

The remaining juvenile fish in the tank ignored the death of the companion and continued swimming into endless laps around the large water tank. Next to them are empty tanks, waiting patiently for new fish farming.

Since 2003, the Spanish Institute of Oceanography (IEO) has tried to cultivate Atlantic bluefin tuna , one of the most sought-after fish species on the market. Through raising this species of tuna from a baby to adulthood, the IEO aims to commercialize fish that are caught too much in the ocean.

Until now, the process of raising fish is still very slow and has many obstacles. The bluefin tuna itself is a great predator and cannot get used to the gentle habitat of the water tank. Adults can grow to the size of a cow, dive the whole number into the depths of the water to feed and a year, they can swim thousands of kilometers. The life of a fish can reach 40 years.

The shape of bluefin tuna is perfectly designed to be a swimmer. Even the extremely favorable appearance of the hydrodynamics of the fish teaches some things to the ship design engineers. In a rush, Atlantic bluefin tuna can reach 60km / h. This is a deadly acceleration in the closed environment of the aquarium.

The fact that the fish rushes into the tank wall dies only one of the numerous difficulties encountered by fish farming. But investors and businesses who shook hands with the IEO did not worry about it: the future potential of raising bluefin tuna is huge, in fact compensating for all difficulties since 2003 for it's time to succeed.

Because bluefin tuna meat is extremely delicious, the need for burning is extremely large . You can see a typical example in Japan: 80% of tuna caught from the Mediterranean will turn into a sushi plate. The popularity of tuna meat has made it face the brink of extinction. Currently, although the status of Atlantic bluefin tuna is still being debated, the International Union for Conservation of Nature is still listed as endangered.

People want to protect wild tuna but still want to ensure the demand of the market is met, so they seek to control the supply. Simply cultivating fish by themselves, they can avoid tightening the management of the fishing industry as well as controlling the consumption of tuna by the people. It seems that a good, endless bluefin tuna is the most reasonable way to solve the problem of name conservation.

"That's why organizations like the EU provide us with research funding and allow us to import tuna eggs to feed," explained Professor Gandara. "Outside the ocean, there is not enough tuna to satisfy the market that is demanding too much."

There is a simpler way to breed salmon, which has existed in the Mediterranean and many other regions since the mid-90s, which are reared in large farms. Unlike the IEO, the fish in this farm were caught from the wild and released into the cage near the sea for 2 to 10 months. When making fish meat, people use a javelin gun to shoot explosives at the fish head, in this way, the fish will die immediately without experiencing the feeling of fear - the reaction will cause the fish to secrete the meat not delicious anymore.

But the fish farming from the time when the leaves of the eggs have remained until adulthood will preserve the wild tuna, due to the complete abandonment of the catch.

Tuna farming is extremely expensive, but due to the extremely large demand, most of them come from Japan, the price can be as high as $ 25 per kilogram of gutted fish."The effort to produce bluefin tuna throughout their lifecycle is based on the requirements of the international market , " said Professor Gandara. "Japanese people pay big money to buy tuna. This high price will maintain our expensive fish farming."

Japan is home to the highest demand for tuna meat, so it is obvious that tuna farming started first here, with Pacific bluefin tuna. Japanese researchers are far ahead of their Spanish colleagues, with a different breed of fish and individual fish farming methods. Right now, Japanese companies have started production lines of Pacific bluefin tuna from eggs. They "closed the life cycle of fish" in 2002.

The term "close life cycle" is used when the aquaculture industry reaches an important milestone: the fish that are born in captive breeding environments, and their eggs hatch into fish. healthy. The IEO reached a milestone on July 2016, after 13 years of trying.

Unfortunately, the IEO has lost most of the fish in a major storm, destroying many facilities. Currently, they are raising fish in an indoor facility, newly opened in 2015.

The mortality rate of bluefin tuna in captivity shows that this process is not easy. Currently, only 0.5 to 1% of Atlantic bluefin tuna was born in the nursery and raised in the Murcia Center to survive the infancy. However, that number is still higher than the survival rate of the bluefin tuna.

A specialized tuna can produce millions of eggs in a breeding season. But outside the natural environment of the Mediterranean Sea, most eggs will be eaten by the same species.

Eating cannibalism is the reason why young tuna does not survive so long. In the culture area, meticulously researched units in the IEO use their hands to divide the eggs into clusters of different sizes, so that big fish do not swallow small fish. This is an extremely ingenious job, since young bluefin tuna has no skin, they will die if we touch it. Researchers have to use small glass panels and separate nets to progress to filter eggs.

Contrary to what you think, the Murcia Center's main facility is to . feed the bluefin tuna feed. Adult tuna eat herring or mackerel, but young tuna are fed by the scientists of the IEO, and they have to raise algae to serve the other fleets. When the bluefin tuna grows a little larger, they will eat other young fish, the fish are also raised at this facility.

It took 3 years for an Atlantic bluefin tuna to hit the minimum size to be able to market, at 40 kilograms.

The World Wildlife Fund WWF, the Ocean Wise organization and the SeaChoice program of Monterey Bay Aquarium are all opposed to eating bluefin tuna, regardless of the type of fish raised, because of the small amount of fish needed. to grow this tuna spot. In some cases, farmers need up to 40 kilograms of herring and mackerel to produce 1 kilogram of tuna. The aquaculture industry needs a lot of small fish to grow big fish, and that is why small fish are also significantly affected. In the Bluefin report in 2016, it was shown that wild tuna and many fishes off the coast of Canada are lacking in food because people catch small fish to grow big fish too much.

In order to balance the amount of fish going in and out, the IEO plans to produce fish feed mixed with fish and plants. There are already people in the field, researchers in Mexico have been using this synthetic food to feed Pacific bluefin tuna.

But the thing is that this way of raising fish will be nothing in the eyes of gourmets, who know tuna meat will depend entirely on what it eats. In the breeding season of fish is May and June, when Atlantic tuna enters the Mediterranean Sea, top chef Paco Garcia prepares premium plates of bluefin tuna at the Ponzano restaurant. Mr. Garcia did not buy the bluefin tuna raised here, he told the Motherboard reporter, while the two were eating a plate of tuna worth 60 euros.

"I prefer to eat tuna more naturally," he said. "The food that these fish absorb is much better."

Expensive tuna dishes with typical flavors can make gourmets satisfied. But for those who day and night worry about the fate of the marine fish ecosystem, the best fish disc of the endangered species are the same: all smelling blood.