The Fisheries Agency has introduced restrictions on the total catch of juvenile bluefin for aquaculture beginning this year. In line with a Western and Central Pacific Fisheries Commission (WCPFC) agreement, purse seining of bluefin aged 1-3 years in the Pacific Ocean has been limited to less than the average of the years 2002 to 2004. Currently, 20 percent of bluefin consumed in Japan is from farmed production, but most farming operations are stocked with wild fry.
Kinki University in Wakayama has succeeded in closed-cycle bluefin breeding, but spawning is triggered by seasonal changes in water temperature and daylight, making year-round supply of fry difficult. To address the problem, the Fisheries Agency will begin operating a controlled-environment land-based facility for spawning bluefin tuna fry in Nagasaki Prefecture next month. The facility alongside Nagasaki’s harbor has two artificially circulated seawater tanks 20 meters around and 6 meters deep. If year-round supply can be established, it may bring down the price of the adult farmed fish.
The attempt at land-based spawning is not the first in the world for bluefin. Port Lincoln, Australia-based Clean Seas, has similarly reared small batches of southern bluefin. However, the company suspended its program in December of last year due to tight finances after high kingfish mortality caused by a lack of the amino acid taurine in its fish feed. The tuna propagation program will be on hold for at least the 2013-14 southern summer.
Despite the ecological advantages of closed-cycle tuna breeding, the costs are still such that university or government support is needed.
Among farmed bluefin, the biggest recent trend is the increase of output from Mexican tuna ranching in waters off Baja California. Operations there have the advantages of nearby supplies of migrating juvenile bluefin, fresh sardines aplenty and low labor costs. This industry has grown to a size that is affecting Japanese prices. Last year, an influx of Mexican farmed tuna in the fall pushed prices downward, with much of the product moving by direct sales to supermarkets, rather than through the auctions.
The WCPFC has strengthened regulation of bigeye tuna catches. For 2013, the commission extended to April from March the traditional seasonal protection period during which purse seining is banned.
Since last fall, prices of bigeye at Tsukiji market in Tokyo have been suppressed by high inventories of Indian Ocean product. This situation has remained, with gradual a gradual decline continuing. In mid-January, the average price at Tsukiji for frozen imported bluefin was 2,625 yen (EUR 20.80; USD 28.50) per kilogram (kg). Southern bluefin fetched 1,680 yen (EUR 13.30; USD 18) and bigeye just 838 yen (EUR 6.60; USD 9) per kg. The wide price spread means that supermarkets will continue to feature bigeye as their mainstay sashimi tuna, a trend that is encouraging a shift in consumer preference toward red meat cuts rather than the fatty belly loin.
