Farming Tuna In Spanish Waters

The fish swim at high speed in a clockwise direction, doing laps and laps of the Spanish Oceanography Institutes tanks of salted water, next to the Mazarrn coastline in Murcia.

In the tank there are around 100 specimens of approximately 1kg in weight while in the sea there is another enclosure which contains a further 200 specimens, which are more mature.

Its not easy to gauge the importance of what is happening. These are the first specimens of Atlantic red tuna bred in captivity. The stock of this species, which is highly valued for sushi or sashimi, has reached worrying levels of over-fishing, so the breeding in fish farms would be a sustainable option to supply demand worldwide without exhausting stocks.

In 2008 an EU funded project, SELFDOTT, got underway, with an investment of 4.3 million. Over the last three years the researchers have collected eggs of one-millimetre in diameter which were laid between June and July in the farms of the Fuentes group, members of the project based near to the Cartagena coast.

The programme did not reap positive results during its first two years, but in 2009 they managed to keep the tuna alive for 73 days and brought them to 30g in weight. In 2010, of the 60 eggs, there remained some young fish that lived for 110 days and reached 100g- nearly a success! Then in July of last year, Manabu Seoka joined the project, a Japanese expert in the larval cultivation of red tuna in the Pacific. With Manabu on the team the results improved hugely, mainly due to changes which were made to the diet of the tuna.

In this sector there are many who are sceptical regarding the future of intensive fish farming of the red tuna, mainly because it takes the fish a long time to reach 300kg, and at the same time cost up to 6,000 per specimen. The argument is that it will always be much easier to go out and fish specimens, than to breed them.