22 October 2011
Spain Spain is leading the race of breeding bluefin tuna in captivity.
Bluefin tuna eggs just before hatching
Tuna swim clockwise at high speed. They swim around and around in a tank of salt water of the Spanish Institute of Oceanography (IEO), which is in the coastal waters of Mazarron (Murcia). There are about 100 specimens with a weight of about 1 kilo and you can almost touch them. There is another cage at sea that holds another 200 older specimens. It is not easy to assess the importance of what is happening here. These are the first Atlantic bluefin tuna bred in captivity. The stock of the species, highly prized as sushi or sashimi, has reached alarming levels because of overfishing. Therefore, the breeding farms may be a sustainable option to supply the world without exhausting the fishing grounds.
The breeding of bluefin tuna is a dream of many years. “Japan began investigating the spawning of tuna in the Pacific 40 years ago and closed the cycle in 2002. With the obvious overfishing in the Mediterranean, 11 years ago the European Union began considering a breeding plan for Atlantic tuna,†says Fernando de la Gandara, researcher at the IEO and coordinator of a European research team involving universities, institutions and companies from eight Mediterranean countries. The last of the projects, the SELFDOTT, worth 4.3 million Euros, began in 2008.For the past three years, researchers have been collecting the eggs, which are about “one millimeter in diameter†that the tuna lay during the months of June and July at the tuna fattening farms from the project partner Fuentes group, off the coast of Cartagena.
During the first two years, the program paid off. The microscopic larvae grew, but when the fry was released into the tank most of them died by crashing into the walls. According to De la Gandara, “at the slightest spur, they shoot out to the sea causing collisions and thus high mortality.†Other species reproduced in captivity, such as bream or sea bass do not have this problem, maybe because they don’t always swim in open water. Sometimes, they come closer to rocks and can therefore distinguish obstacles.â€
In 2009, researchers achieved the tuna to live for 73 days and reach a weight of about 30 grams. In 2010, 60 million eggs resulted in a few living fries, however these died after 110 days at a weight of 100 grams. That was a partial success. In July last year, the Japanese Manabu Seoka, an expert on larval rearing of Pacific bluefin tuna, joined the team. “Manabu gave us a boost. Would we have achieved it without him? Yes; however, not in such a short period of time,†says De la Gandara.
Manabu Seoka is a friendly person who settled in Cartagena together with his wife and two young children. With him on the team, the results this year are much better, mainly because of changes in food, because it is important to feed the just few millimeter-seized larvae with enriched zooplankton. The plankton is grown at the research center. Then they are give larvae from other fish. An adjustment of the diet is important. “We’ve already been successful. The tuna now have to mature and as soon as they’ve reached 4 years of age, they will be able to reproduce. This has already been achieved in Japan,†says the researcher.
The process has not generated any patents; it is more about learning to manage a very sensitive species than to develop breakthrough innovations. “We are public researchers, although there are also companies involved in the project. It’s not as if any will be able to do this tomorrow,†says De la Gandara.
The IEO research is probably the most advanced in an already started race. The company Futuna has settled in El Puerto de Santa MarÃa (Cádiz). It expects to produce fry within a year, according to the company’s manager, Miguel Llerena. The firm, owned by venture capital from various countries, says it will invest between 12 and 15 million Euros in the facility. Its business is to buy about 60 reproducing tuna from the Cadiz trap netters and keep them in a tank on land. Consequently, obtain the eggs, raise them until they are between 25 and 50 inches and sell them to the farms, which will fatten them before selling.
The Croatian company Umami has also announced progress in breeding, in collaboration with the University of Split.
There are those in the sector who are skeptical about the future of aquaculture bluefin tuna, especially because the fish takes many years to reach 300 kilos, which is about the weight a blulefin tuna can weigh and is what enables them to sell for up to 6,000 Euros/each at the Tokyo fish market. The argument is that it will always be infinitely cheaper to go out and fish the tuna than to grow them. It will also be cheaper to do what is being done today: catch medium-sized tuna and fatten them in cages at sea until they reach the optimum weight and fat.
De la Gandara says it’s a repeating story: “I’ve been in the aquaculture sector for 30 years and always hear the same thing: that cultivating the fish cannot compete with catching it. And this is true if the sea is full of fish and there’s no need to go far to catch it. However, this is not the case if you have to go far away and have high costs. The evidence is that most of the bream and sea bass that is sold today are farmed.â€
Llerena also sees “big businessâ€: “This can change the entire tuna fishery. Now it is necessary to have vessels, cold storages ... What we are proposing involves a location and coastal cages.†Bluefin tuna is a business that moved about 6,000 million USDollars (about 4,330 million Euros) in the year 2000, according to the European Commission.
Seoka has no doubt that there will be room enough for farmed sushi even when bluefin tuna stock is improving thanks to the latest control measures: “The Chinese are starting to eat tuna. Who is going to supply China? Farmed tuna encounters no environmental restrictions as it is not being retrieved from the sea.â€
