Where our Tuna comes from…

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More thoughts from Dale Sims, co-founder of CleanFish, California-based distributor of Loch Duart salmon


“It feels as if it’s melting in my mouth…” – Eric Asimov writing about maguro sushi in the New York Times

As I have often said, the bluefin tuna is the most controversial fish in the ocean. It is a symbol of everything that is wonderful about fish but also of the incredible difficulties of achieving sustainability in our global fisheries.

The problem is that we like bluefin tuna so sooooo much we’ve severely overfished it – and the main response to diminishing stocks is the search for increasingly sophisticated methods of finding and catching what’s left. For once, we Americans are relatively guilt-free – the most relentless tuna fisheries are elsewhere.

American commercial fishermen did not pursue tuna in the western Atlantic until about 1960. In 1973, fishermen off the coast of New England received slightly more than $1.00 a pound for bluefin. At the start of the 1985 bluefin season in the Gulf, the first bluefin of the season was sold to the Tsukiji market in Japan for $25,000 – for one fish. Just thinking about that today makes me cringe. In 2012 a 593lb bluefin sold for $736,000. This year, on January 5th, a 222kg (489 lb) bluefin caught near the town of Oma in the Aomori prefecture in NE Japan fetched a whopping $1.76 million smackaroos. Is this insanity or what!

As sushi becomes ever more popular in America and around the world, the demand for luxurious bluefin tuna will only increase. We must not allow ourselves to eat bluefin into extinction.

Thankfully, after more than 30 years of research, a 100% completely farmed from egg to harvest bluefin tuna is available. This is the Kindai bluefin – developed by researchers at Kinki University in Japan. They figured out how to get bluefin tuna to spawn in captivity. The Japanese first successfully hatched and farm-raised bluefin tuna in 1979. In 2002, researchers at the Kinki University Fisheries Laboratory artificially bred bluefin tuna fry from artificially incubated mature tuna. Finally, in 2007, they successfully completed a third generation, fully closing the loop on the production cycle. These bluefin were first raised exclusively by the university, but that has changed. CleanFish is now proud to offer our American customers bluefin tuna raised by Dainichi of Japan. Dainichi is one the few companies that works with Kinki University to provide a fully sustainable bluefin tuna, farm-raised from egg to harvest.

Dainichi’s farm site is ideal for raising tuna. There is a steady current of 7 knots with a water depth of 130+ feet. They have the benefit of the Kroshiro current that moves 50 million MT of water per second along the coast of SE Japan. The stocking density never exceeds 2kg/m3. Numerous pearl farms in the region act as natural bio-filters. The tuna are hand-fed fresh pilchards and a specially formulated pelleted feed. When the university first began farming bluefin, the feed conversion ratio was very high, at 22:1. Today, that has improved to 8:1 – high perhaps when compared to salmon but acceptable in the context of the value of the fish and the conservation issues at stake.

Today, we can benefit from the many years of work by researchers at Kinki University and their cooperation with Dainichi. A 100% farmed from egg to harvest bluefin tuna is available. The fish are havested one at a time, strictly to order. They are are caught by pole and line. They use percussive stunning, after which the fish are immediately bled, gutted and rapidly cooled in an ice slurry.

Bluefin can be the most exquisite of tunas. The fattiest part of this fish is both rich and sweet, with a soft buttery texture. Prepared as sashimi, it might be described as cascading like raindrops falling on the tongue. We are proud to join with Dainichi to offer a farmed bluefin tuna that has no impact on wild blue fin stocks. This year’s harvest season is limited. Fish are available only until early June – so let’s learn to eat tuna when we can, not every time we want to.

Dale Sims