Japanese pearl industry rocked by 20 million oyster die-off

Japan Times -- Nov 02
The mysterious death of over 20 million Akoya pearl oysters in Ehime, Mie and other prefectures this summer is expected to hobble pearl production next year and beyond.

While the cause of the die-off is unclear, oyster producers have started taking steps to minimize the damage.

It takes three to four years to produce a cultured pearl, which the oysters make by depositing layers of nacre around a tiny bead inserted into their shells.

Ehime, the largest producer of Akoya pearl oysters in Japan, noticed the die-off in late July. At the end of September, the young shellfish cultured there stood at about 11 million, nearly 70 percent below average.

The die-off was the first in Japan since 1996, according to Takeshi Miura, a professor at Ehime University’s Faculty of Agriculture.

Though the exact cause has not been identified, Miura said, “It occurred as a result of multiple factors,” including underfeeding and overcrowded environments.

The cost to Ehime reached ¥300 million at the end of September, and the loss is expected to dent production of cultured pearls, which are a huge income source for its economy.

Pearl production by value in Ehime fell to about ¥5.2 billion in fiscal 2019 from ¥6.1 billion in fiscal 2018, mainly due to the economic slowdown in China, a major export destination. In fiscal 2020 the figure is expected to sink to around ¥4 billion.

- Japan Times