The different areas of Nori cultivation

Different types of Mikuniya nori from the 4 different production regions.

When we think of the Japanese environment, what are some of the images that we default to? The lush picturesque paddy fields, Mt Fuji, and the Japanese Alps. One thing that is often forgotten is how the country is stretched longitudinally. What that means is that the climate, as well as the aquatic ecosystems, differ considerably. For the Nori industry, this affects the seasons during which nori is produced, as well as the flavours, colours and textures (all factors explored in our previous article).

We explored the nuanced taste of Nori in our last article, but what factors into the change in flavour is the temperature of the water, the type of minerals found in the water, as well as the cultivation method, which is influenced by the location of the product.

Map of key nori production ones

In Japan, there are 4 key cultivation areas of Nori dotted throughout Japan:

  • Ariake Sea (Saga, Fukuoka, Kumamoto, Nagasaki Prefectures)
  • Seto-Inland Sea (Hyogo, Okayama, Shikoku)
  • Mikawa Bay (Aichi Prefecture)
  • Tokyo Bay (Chiba Prefecture)

Ariake Sea

The Ariake Sea is an inland sea surrounded by Saga, Fukuoka, Kumamoto, and Nagasaki prefectures. Dot in the centre of Kyushu its unique ecosystem makes the Ariake sea a prime growth bed for nori spores.

The sea produces the highest quality nori in all of Japan. Its unique geographical location is key to growing rich nori seaweed that has compact umami flavours as well as the ‘melt in your mouth’ quality. With over numerous key river sources emptying out into the river (Chikugo River, Yabe River, Rokkaku River, Shioda River, Tagori River, Kikuchi river, Shirakawa river, and Midori rivers, to name a few ), the rich water blends with the seawater, diluting its salinity and providing a rich environment for healthy seaweed growth . This results in the deep dark coloured nori, with the melt in your mouth texture as well as the rich umami flavours that are lauded in the culinary world. The most remarkable aspect of the Ariake sea is that depending on the coast the type of nutrition found, the salinity levels, and the flow of the water all change the taste of the nori produced.

Nori producers pulling up the nets.

Saga prefecture is located on the northwestern side of Kyushu sandwiched by Fukuoka prefecture and Nagasaki prefecture and covers the northwestern part of the Ariake sea. It is known as the nori producing prefecture since it produces the highest amount of nori sheets per annum. Due to the movement of the water of the Ariake sea unique to the northwestern coast, the type of nutrition found in that part of the Ariake sea is different from the rest of the prefectures.

In addition to the unique nature of the Ariake coast, the method of production is designed in such a way that it finds the perfect balance of the spores being underwater (for colour) and exposure to the sun (for flavour). The methodology is called shichuushiki where the nets are set in such a way that it takes advantage of the rise and fall of the tide to control the amount of time the nets spend underwater. This results in the high-quality nori that we find in Mikuniya today.

The rest of the Ariake Sea, with Kumamoto, Fukuoka and Nagasaki, is also renowned for its deep black hue and its rich flavours. However, because of the difference in both nutrition in the water, the flow of the current, and the production method, the richness of the flavour differs considerably from that of Saga prefecture. Next to Saga, Fukuoka has the second-highest production rate of nori followed by Kumamoto and Nagasaki. At Mikuniya, we specialise in using the highest grade products that come from the Ariake sea, and you can find them in the majority of our products.

Seto Inland Sea

This is the second biggest production zone of nori in Japan. Compared to the Ariake sea it is not as soft and supple but still has its own unique flavours. Due to the longitudinal shape of the sea ecosystem, depending on where the seaweed is produced in the Seto Inland Sea, the flavour and depth of the nori can differ. This type of nori is suited for makizushi.

Mikuniya Nori from Seto Inland sea (Hyogo Pref)

The method of production commonly adopted in this area is the tsukarippanashi where the seaweed nets are placed underwater for most of the growing term. That is why the nori found in this region has a deep black hue that is considered visually beautiful among sushi chefs in Japan, and highly valued among consumers. Awaji Island is one of the largest producing areas in the Seto inland sea.

The shimmer of the nori

Mikawa Bay, Tokyo Bay

Grown in Mikawa Bay, since Nori production has many competitors, the farmers in Aichi Prefecture have found unique ways to cultivate their produce to keep them competitive. Depending on the farmer they either produce their nori via the shichuushiki method and the tsukarippanashi method. Interestingly, the nori in the Mikawa bay has changed considerably due to the development of the Chubu National Airport in Aichi prefecture. That impacted the flow of the current in Mikawa bay, resulting in the improvement of the quality of nori in some areas, and decreasing the quality of nori in others.

Mikuniya Nori from Mikawa Bay (Aiichi Prefecture)
Mikuniya Nori from Tokyo Bay (Chiba Prefecture)

Chiba and its nori are famous for their exponential production and use during the Edo period. The now-famous Edo-maezushi, used the nori cultivated in Chiba. However, due to industrial development and the rise in temperatures, it has ceased to become a prevalent production zone for Nori.

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As we can see from the different regions above, Nori is a product that is highly sensitive to the environment around them that cannot be controlled during the production process. But their sensitivity opens up immense possibilities of flavours and textures making nori from each region unique. At Mikuniya there is an array products from all parts of Japan where you can compare to see which ones you like the most.

Sunset over the Ariake Sea



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