Record poor harvest drives down Japan seaweed output to 51-year low

Output of nori, the seaweed which is indispensable to onigiri rice balls and other Japanese cuisine, hit the lowest level in 51 years in the 2022 harvest year, due to bad weather and a red tide outbreak in the Ariake Sea, Japan's biggest seaweed producing region.

With farmers' prices having soared 46 per cent from the previous harvest year, Japan's leading processed seaweed makers plan to raise the suggested retail price of seaweed for home use by up to 40 per cent starting this month. The steep price increase for this familiar ingredient is likely to place a heavy burden on consumers.

During the 2022 seaweed harvest year -- which runs from November 2022 to May 15 this year -- about 4.8 billion sheets of nori seaweed were produced in Japan, falling below 5 billion sheets for the first time in 51 years, according to data from the Seaweed Business Promotion Council of National Fisheries Federation. The figure was about 2.7 billion sheets short of the country's domestic demand of 7.5 billion sheets, reports Nikkei Asia.

The national average of fishery cooperative federations' joint selling price per sheet (19cm x 21cm) is 17.24 yen ($0.12), up 46 per cent from the previous harvest year. The price per sheet exceeded 17 yen for the first time in 40 years.

A decline in seaweed output is due to a bad crop in the Kyushu region, which accounts for 60 per cent of seaweed production in Japan. During the latest harvest season, red tides occurred in the Ariake Sea due to little rain and high ocean temperatures. As a result, it seems that seaweeds did not grow sufficiently due to a lack of nutrients in the sea.

Among four prefectures surrounding the Ariake Sea, Saga, the biggest seaweed producer, was hardest hit by the poor crop. The prefecture produced about 900 million sheets of seaweed in the 2022 harvest year, falling below 1 billion sheets for the first time in 22 years, according to Saga Prefecture Fishery Cooperative Federation. The prefecture's seaweed output also declined in value.

"Bad growing conditions came one after another. We have never had anything like this," said a representative of the Saga Prefecture Fishery Cooperative Federation. Saga had been Japan's biggest seaweed producer for 19 consecutive years until it was overtaken by Hyogo prefecture last year.

Bad weather also had a negative impact on the quality of seaweeds, which grow by absorbing nitrogen and phosphorus. With not enough nutrients being supplied from rivers due to little rain, the seaweeds became discolored.

As a result, the Saga Prefecture Fishery Cooperative Federation and Saga prefecture decided not to certify seaweed produced in the 2022 harvest year as the finest "Saganori Ariake-kai Ichiban" brand. It was the first time that the brand was not certified since it was founded in 2007.

The seaweed price per sheet has also been rising due to a decrease in supply. The price of seaweed produced in Saga prefecture now goes for 18.48 yen per sheet, up 45 per cent from the previous harvest year. "We are worried that consumers may shy away from seaweed because of soaring prices," said a representative of the Saga Prefecture Fishery Cooperative Federation.

Prices for seaweeds grown in other prefectures have been on the rise as well. Prices for those produced in Hyogo and Miyagi prefectures have respectively surged 57 per cent and 62 per cent from the previous harvest year.

Tokyo-based processed seaweed maker Shirako plans to raise prices of the product for domestic use by up to 40 per cent, marking the company's first price increase in four years.