A new way of creating sushi has been developed in Japan, and it has created shock waves in both the farming and aquaculture worlds. It has been called “sushiculture” and as its name implies it raises sushi directly as one product in one farm. As Dr. Makoto Nakazato explained in his presentation at the World Aquaculture Society conference in Nashville, “The problem with sushi is that its ingredients are sourced from such different parts of the world, with rice farmed in China and tuna coming from the Western and central Pacific. We wanted to bring them together.”
The concept is quite simple. Rice is grown in flooded fields as has long been the tradition, but in sushiculture there are freshwater-tolerant tuna swimming among the rice stalks. At the time of harvest, both the rice and tuna are brought together using a modified combine harvester that rapidly boils the rice, mixes it with seasonings and forms rice balls while the tuna is processed and sliced. In the final step the tuna is pressed onto the rice to create “nigiri” sushi and each piece is placed into black plastic to-go containers and wrapped, ready for distribution around the world.
The tuna raised is a species known as the April Tuna (Thunnus aprilfoolii), named for the day it was discovered. Freshwater tuna were required for sushiculture due to the water needed for rice farming. There was also another reason for this species selection: growth time. Rice takes only 3-6 months to reach maturity, while some of tuna take 4-5 years to reach adult size. “The species of choice for sushi is bluefin tuna, but April Tuna grows quickly enough to be harvested at the same time as the rice. It is also far more sustainable.,” Dr. Nakazato explained.
Dr. Nakazato’s future plans include incorporating cucumber and avocado farms to be able to produce California rolls and seaweed culture to create the seaweed wraps.