Bringing Fully-Farmed Bluefin To The Market

At a time when the amount of bluefin tuna left in the Pacific Ocean is scarce, and fishing bans have been put in place in order to protect the species, alternative methods need to be explored if the taste for the fish will continue to be satisfied.

As fishing alone is struggling to meet the global market demand, there is an emerging trend of firms, especially in Japan, wanting to sell fully-farmed bluefin tuna both domestically and abroad. And several companies have set a goal to do this, all battling to bring it to the market, with some already having succeeded in the mission.

Fully-farmed bluefin indicates that the fish has been raised in captivity, from egg to adulthood.

Up until now, farming fish has actually usually meant fattening; the fish is caught in the wild as juveniles and then fattened in pens. However, since this has also jeopardized the stock by taking away fish that would mature and procreate, it is not regarded as being more environmentally friendly than wild fishing.

Japanese fish farms altogether fattened 15,000 tons of bluefin tuna in 2015, but less than 300 tons were raised from eggs into maturity, according to Japanese news sources.

The farming procedure of bluefin is notoriously difficult as the mortality rate for juveniles is very high. Usually only around 0.6 percent of larvae reach 50mm in length and continuous research is being done in order to increase the survival rate.

But a lot is happening in this field, and recently a race to supply fully-farmed bluefin to the market has started, with a handful of companies now striving to bring bluefin to the consumer during the next few years.

Three Japanese seafood companies, Maruha Nichiro, Kaneko Sangyo and Nippon Suisan Kaisha are self-confident that they will start supplying a total of tens of thousands of fully farm-grown bluefin tuna annually.

Kindai University in Osaka, Japan, has been a frontrunner when it comes to farming bluefin, first succeeding in full aquaculture in 2002. It was prompted to begin research on how to raise the popular fish from egg to adulthood when it noticed fishermen struggling to meet the market demand for the fish.

“People are now demanding tunas for the delicious and healthy food, and are caring about the sustainability of food production. Tuna meat contains much high quality protein and their fat is much more healthy than that of the meats of animals such as beef, pork, and chicken,” Professor Yoshifumi Sawada from the University’s Aquaculture Research Institute told Atuna.

He explains that through the University’s success in industrializing full-cycle tuna production, it has spurred a motivation in companies to follow suit and ensure it is seen as a good alternative to wild fishing.

“Regarding the sustainability of the tuna production, the full-cycle aquaculture is the most promising way.”

According to Sawada, tuna aquaculture requires an especially clean and calm environment in order to be successful and the bluefin gains only one kilogram body weight per 10 to 15kg of raw fish it eats.

“This poor food conversion rate will put a restraint on the expansion of tuna,” he says.

The sustainability of bluefin farming has faced criticism because the volume of eat the tuna require is substantial, as they need to feed on a large amount of wild-caught fish such as sardines.

However, alternative tuna feed is now vigorously being developed, for example soy bean protein, corn protein and recycled animal protein. Sawada states the ultimate goal for Kindai is to make the tunas become vegetarian.

He does not however see tuna aquaculture as a substitute for wild-caught tuna, and emphasizes that it is necessary to supply tuna both through farming and wild-fishing, as a variety of both is what is needed to ensure sustainability.

If all goes according to plan, Japanese consumers may find affordable fully-farmed bluefin in supermarkets as early as next year and consumers in the Western world might find it in supermarkets in the next few years.