AQUAFARMING
Index
Production Area
Q.Where in Japan are fish farmed?
A.Yellowtail and sea bream are mainly farmed in the warmer sea, where the Kuroshio current flows around Japan.
Q.Where are the major production areas of yellowtail in Japan?
A.
Yellowtail is the major farmed fish in Japan, mainly produced in Kyushu and Shikoku regions. According to the Ministry of Agriculture, Forestry and Fisheries statistics in 2022, the top three production prefectures are Kagoshima with 21,600 tons, Oita with 14,800 tons, and Ehime with 13,900 tons.
Q.Where are the major production areas of red sea bream in Japan?
A.
According to the Ministry of Agriculture, Forestry and Fisheries statistics in 2022, the top three red sea bream production prefectures are Ehime with 38,600 tons, Kumamoto with 11,000 tons, and Kochi with 5,600 tons.
About “baby fish”
Q.Where do Buri (yellowtail) baby fish come from?
A.
Farmers raise buri from baby fish called mojako, which are born naturally. Mojako are caught around April and May when they are found in floating seaweed around southern coastal areas in Japan, such as the Kyushu region.
Q.How are madai (red sea bream) baby fish caught?
A.
Almost 100% of farmed madai are raised from artificial seeds, which grow faster than naturally raised baby fish.
About shipping
Q.How long does it take mojako ( buri baby fish) to grow big enough to ship?
A.
It takes 1.5 to 3 years. Around autumn in the second year, mojako grows to 4 kg in weight when most of them are shipped.
Q.When is it ready for madai to be shipped?
A.
After 1 to 2.5 years in ikesu (fish pens), they grow to around 1 to 2 kg and are ready to be shipped.
About catches
Q.Which yield more catches, buri and medai, farmed and wild fish?
A.
Farmed madai catches are four times more than wild madai. Farmed buri catches slightly more than wild ones.
About feed
Q.What do farmed fish eat?
A.
Farmers used to give live fish, such as sardines, to buri. Today, they rarely use only live fish because of decreasing marine resources and the preservation of the environment. There are Moist Pellets (MP), made of live fish and fish meal; Dry Pellets (DP), made of fish meal and soybean oil cake; and Extruded Pellets (EP), a compressed solid feed. DP and EP are environmentally friendly feeds that do not fall apart in the water, avoiding polluting the ocean
Approach to the SDGs
Q.What do fish farmers do for the sustainable fisheries?
A.
Farmers give compound feed by hand to baby fish, including red sea bream, so as not to pollute the ocean with the leftovers. When the fish grow enough to eat the specified amount of feed, they are fed by an automatic feeder. The automatic feeder developed recently is AI-controlled to analyze fish’s appetite and feed properly. That enables the reduction of the impact on the environment by reducing the feed waste.
Q.Is aquafarming an environmental-friendly?
A.
Supply of artificial seed to farmed fish is stable year around, and it allows to preserve the natural resource in the ocean. Artificial seeds that do not require the harvesting of mojako are attracting attention in buri aquafarming these days. The harvest of mojako is limited to a certain amount and for a certain period to protect the natural resources.
About safety and security
Q.Is Japan’s aquafarming safe?
A.
Japanese farmed fish adhere to strict standards set by the government to produce safe farmed fish. The size and num – ber of cohorts in fish farms and the number and density of fish kept in the cohorts are limited. Fish are kept in sepa – rate cohorts according to their level of growth. Various in – formation, such as the condition of the fish and water tem – perature, is managed to ensure that they grow in a healthy and standardized quality. In addition, sanitary manage – ment in accordance with HACCP is required at processing plants for export and domestic use.
About the traditional harvesting method
Q.What is Ikejime?
A.
It’s a method to prepare live fish instantly by cutting the medulla oblongata of fish. Simultaneously, the gill membrane and the caudal vein are cut to bleed it out. Removing the blood helps to reduce discoloration and fishy odor. To bring out the umami of the fish, it is essential to leave a lot of ATP (adenosine triphosphate). In other words, ATP is not consumed by preparing the fish without letting it thrash around, delaying rigor mortis.
Q.Whati is Shinkei-jime?
A.
“Shinkei-jime” is a method of preparing live fish to keep its meat delicious with an umami flavor. First, the blood of live fish is drained by cutting the medulla oblongata and the caudal vein. Afterward, to prevent rigor mortis, the spinal cord is destroyed by the wire or removed by injecting air from the tail. Then, fish are kept at the appropriate temperature to retain ATP. The ATP left behind without being consumed in this way turns into inosinic acid, an umami component in the fish’s muscles. This inosinic acid is the umami component that gives the fish its “dashi” flavor. Additionally, the umami component glutamic acid found in fish meat enhances the umami flavor.
Where can we eat them?
Q.Do Japanese conveyor belt sushi restaurants use farmed fish?
A.
Major conveyor belt sushi restaurant chains offer farmed fish sushi as a seasonal, limited menu.
About export
Q.In what form is the farmed fish exported?
A.
Korea is one of the major export countries for live madai (red sea bream). They are exported in the form of chilled whole round and chilled fillet. Buri is exported live, chilled, or frozen. Frozen fillet is popular in the United States.
Professor Ariji:
Cool! Japan’s craftsmanship in aquafarming
Dr. Masahiko Arijiis a professor of the Laboratory of Strategies for Fisheries and Food at the Kindai University Institute for world Economy.
He is also a member of the Council for Regulatory Reform Promotion of Regional Revitalization WG, an associate member of the Science Council of Japan, and a committee of the Aquaculture Growth Industrialization Promotion Council.
He developed “Kindai Catfish” and “Smell-free amberjack.” He is president/CEO of SHOKU EN CO., Ltd.
He is also a member of the Council for Regulatory Reform Promotion of Regional Revitalization WG, an associate member of the Science Council of Japan, and a committee of the Aquaculture Growth Industrialization Promotion Council.
He developed “Kindai Catfish” and “Smell-free amberjack.” He is president/CEO of SHOKU EN CO., Ltd.
Amazing Japan’s Aquafarming
The world’s first Buri farming started in Kagawa prefecture, using ikesu, a fish farming pen developed by Kinki University about 70 years ago. The technique has spread all over Japan and to Asian countries, including Taiwan and worldwide. Before the ikesu, fish were farmed in the bay by separating, but it caused cannibalization and disease outbreaks. So, they thought of grouping fish. Most farmed fish in Japan are produced for eating raw, such as sashimi or sushi, meaning that the quality comes first. They must be safe and taste umami, so farmers raise fish carefully by paying attention to various things, such as adjusting feeding.
Raising Umami-rich Fish and Processing them
Fish farmers in Japan have tried to raise good fish in taste and appearance. For example, to raise sea bream evenly healthy, they practice selective breeding. The feeding technique is another effort to produce tasty fish; the feed is blended to taste like dashi (Japanese stock) when eaten as sushi and sashimi. For Japanese, tastiness often means dashi-like flavor, and dashi is full of umami flavor. Umami has become a universal word worldwide. As the farmed fish is produced to eat raw, fish are killed by a unique method called “shinkei-jime.” This method kills them in their most delicious state, keeping them fresh and umami-rich. Japan’s farmed fish, developed to be umami-rich, will be recognized by people worldwide as “if you want a tasty fish, choose Japanese farmed fish.”