Ise-Shima’s Pearl Culture 【自然と人】山を楽しむ<ユニボイス>：谷川岳ロープウェイ、山岳資料館、登山指導センター、利根川、温泉等

Mikimoto was born the son of a noodle-restaurant owner in the city of Toba, and made his first attempts at pearl cultivation in 1888. For four years, he set up farms around Ago Bay, only to have most of his oysters killed by a red tide—a profusion of plankton that can wreak havoc on marine life—in 1892. In the following year, he was able to produce hemispherical cultured pearls, and in 1905 he succeeded in creating the world’s first perfectly spherical cultured pearl.

The process of cultivating pearls is delicate, and involves a number of steps. Mantle tissue and a bead made from the shell of a mollusk are surgically placed inside a mother of pearl oyster. This causes the secretion of nacre, which accumulates around the bead to form a pearl. In the past, the oysters were collected and returned to the seafloor with the help of ama divers, but today they are placed in cages on the pearl rafts that dot the bays. It takes about two years for a pearl to grow, and the oysters must be meticulously tended.

The ria coast and sheltered inlets of Ise-Shima are an ideal place for the production of pearls. Protected from strong wind and waves, the waters are calm enough to provide the stability necessary for pearl rafts. The consistent temperature and salt content of the water allows the oysters—as well as their primary food source, plankton—to thrive. Even a small change in any of these factors can result in an imperfect pearl when harvest time comes.

Ise-Shima continues to be an important location for pearl research and cultivation. Visitors can learn about the cultivation of pearls, participate in pearl crafting workshops, and purchase pearl souvenirs.