Aquaculture for all

Dainichi: The Face of Japan's Clear Sea

Nutrition Tuna Husbandry +8 more

JAPAN - Dainichi Corporation is one of Japan's main seafood and aquaculture firms. Located by the Uwa Sea in Ehime prefecture, it employs 140 people in three cities in Japan and one in the US. Since its foundation in 1982, it has specialised in bluefin and red sea bream farming, feed production and research.

Lucy Towers thumbnail

Its employees and stakeholders pride themselves on being industry leaders and work to create healthy, delicious, nutritious and traceable seafood. Its main customers are national retailers, department stores and restaurants across Japan, such as conveyer belt sushi chains.

The Uwa Sea is one of Japan's premier fish farming areas. It provides abundant marine resources and has allowed coastal fisheries and aquaculture to develop greatly, making Ehime a leading producer of aquaculture products.

Aiming to grow while protecting the Uwa Sea's resources, Dainichi takes what it calls a multidirectional approach, focusing on areas such as quality control, logistics and technology while working with international target markets, as overseas interest in Japan's food culture continues to increase.

Below is an outline of Dainichi's field of activities.

Bluefin Tuna Farming

Amidst concerns over declining bluefin tuna stocks, 28 local fish farmers established an association called the Uwaumi Fishermen's Production Association for Tuna Aquaculture in April 2005. Dainichi joined in 2007.

Today it rears artificial seeds from Kindai University until they grow to around 40-45kg. The tuna are then sold under the brand name Hime Maguro, or Princess Tuna.

A group of farmers and an aquaculture and fishery nutrition professor rear the tuna in open net cages of around 70m in diameter at a stocking density of 2kg per cubic metre. Water temperatures are around 15-25°C.

Hand fed a mix of pilchards and specially formulated pellets, the tuna are harvested individually by pole and line between October and June to achieve an optimum meat breakdown of 40 per cent akami (red meat), 40 per cent chu-toro (medium fatty meat) and 20 per cent o-toro (high fatty meat). They are then immediately bled, gilled and cooled in ice water before being shipped across the country.

The Farming of Red Sea Bream

Dainichi also operates an internationally patented farming method to produce premium red sea bream in the Uwa Sea, where 30 per cent of Japan's red sea bream production occurs.

Marketed as Shinkai Madai, or deep-sea red sea bream, the fish are reared at 40-50m in galvanized steel nets that prevent escapes.

Because wild sea bream are usually found in the deep sea, the farming method ensures that they are reared in conditions as close as possible to the natural environment.

High water pressure results in firmer flesh quality and denser muscles while ultraviolet rays are unable to penetrate the deeper depths; this prevents melanin generation and gives the fish a bright red colour.

A specially formulated diet rich in shrimp, squid meal and sand lance (ammodytes personatus) is pumped through a feeding hose into the pens, while an underwater camera monitors feeding behaviour so that feed amounts and frequency can be adjusted accordingly. Uneaten feed and waste are also collected and pumped back to the surface.

Transport and Maintaining Freshness

The Dainichi Kainan Seafood Center in nearby Wakayama Prefecture is a HACCP-certified processing plant that's 30 minutes from Kansai International Airport. Various species are held in recirculating tanks and each year 1,200 fish are processed every hour before being vacuum-packed and loaded onto refrigerator trucks.

The centre's location means that the fish can be shipped directly overseas in as fresh a state as possible, eliminating the need to distribute via Tokyo. Also nearby is the Kainan Interchange of the Hanwa Expressway that connects the cities of Wakayama and Osaka, making domestic distribution quicker and easier.

To keep its products fresh, the centre uses slurry ice, a free flowing mixture of desalinized seawater and spherical shaped ice with a diameter of only a few millimetres. The ice's shape increases the cooling surface area and the fish can be cooled quickly without damage. Slurry ice can also completely surround the fish and fill gaps, thus decreasing temperature irregularity during processing.

Spinal cords are removed during harvest, which bypasses rigor mortis and increases shelf life. Strict quality control is in place; the fish are tested for any residual antibiotics, swab tests are regularly performed and a biofilter is used to process water containing blood.

Consultations and Quality Control

With a laboratory in place for the research of fisheries and disease, Dainichi also offers consultations on feed formulations and fish health, covering a range of areas such as nutritional supplements and medication to address disease. Products and raw materials are also checked daily to ensure that they are safe, with sterilization machines, incubators and other equipment necessary for testing and inspections.

Dainichi's management theory is "Quality without Borderlines." With a total support system that aims to offer products that are best suited to clients and consumers, the company aims to ensure that its safety and reliability are fully recognized.

For more information on Dainichi, visit the company's website at:

Create an account now to keep reading

It'll only take a second and we'll take you right back to what you were reading. The best part? It's free.

Already have an account? Sign in here