Chronology of freshwater cultured pearls in Japan

1904 (Meiji 37) Tokujiro Koshida, an engineer at the Hokkaido Fisheries Experimental Station, used a Japanese snail living in the Chitose River to insert pellets, grains of sand (of size 5 rin to 1 bu = 1.5 to 3mm), and pieces of pottery as cores between the mantle and shell. The pearl cultivation experiment is said to have lasted for about one month. The result was failure.

In 1910 (Meiji 43), Sumiki Kawashima, the governor of Shiga Prefecture at the time, was inspired by Mikimoto's invention of hemispheric (mobe) pearl cultivation technology and attempted it in Zeze, Otsu City using large bivalves such as mengai (Spondylus squamosus schreibers) from Lake Biwa. . The result was failure.

In 1917 (Taisho 6), the governor of Shiga Prefecture at the time, Masatatsu Mori, asked Mikimoto to send an engineer (experienced in ocean pearl cultivation using Pinctada oysters) named Watase from Mie Prefecture, who made freshwater cultivation experiments at Onuma in Noda, Nakasu-cho, Yasu-gun, Shiga Prefecture, but it was unsuccessful. (mother shell species used is unknown).

1924 (Taisho 13) Masayo Fujita plans to cultivate pearls in Lake Biwa. Together with Keizaburo Mukaiyoshi, Mitsujiro Tanaka, and others, he began research on pearl cultivation using crayfish at the Kyoto University Rinko Experimental Station in Otsu, with the cooperation of Director Tamiji Kawamura.

1925 (Taisho 14) With the support of Masayo Fujita and Toranosuke Yoshida, head of the Omi Fisheries Association, the fish farm was moved to Lake Tairakonai in Shina-cho, Kusatsu City, and research continued.

1927 (Showa 2), Toranosuke Yoshida became the founder of the Freshwater Pearl Culture Research Group.

1928 (Showa 3) The Freshwater Pearl Cultivation Research Society failed in cultivating pearls from Japanese snails, but it had been discovered that the Ikechogai (Hieryopsis schlegeli) is suitable for pearl farming.

{In this period, Masayo Fujita is credited for introducing Ikechougai (Hieryopsis schlegeli) to Kasumi-ga-Ura.}

1930 (Showa 5) Masayo Fujita succeeded in cultivating pearls with commercial value using Ikechogai. Samples of pearls, called Fujita-style rose pearls, were sent to India, China, England, and other countries.

1934 (Showa 9) Masayo Fujita comes to Shiga Prefecture to conduct research and gain prospects for commercialization.

1935 (Showa 10) With the financial support of Kokichi Mikimoto, the Freshwater Pearl Cultivating Corporation was established with Hachiemon Kazama as its president. (He changed the name to Biwako Pearl Corporation the following year).  Full-scale aquaculture business began, took off and products were exported overseas. 

1938 (Showa 13) Business ceased due to lack of materials and loss of market due to the Pacific War. 1942 (Showa 17) Due to the outbreak of World War II following the China Incident, the Biwako Pearl Cultivation Company was dissolved.

1946 (Showa 21) Shinko Shinju Corporation established by Masayo Fujita and Seiichiro Uda*. Efforts so far had concentrated on ocean pearl style in-body bead nucleated pearls, but the decision was made to cultivate non-nucleated pearls instead. Non-nucleated pearls are cultivated within the mantle of the mother oyster. A technology has been developed to do so.

{Technology for in-body nucleated freshwater pearls were later introduced by Haruo Sakai.}

1948 (Showa 23) Masayo Fujita revived the Biwako Pearl Company, and established a fish farm in Kinugawa, Katata-cho, Shiga-gun, Shiga Prefecture, and began operations.

1949 (Showa 24) Shiga Prefecture Pearl Cultivation Cooperative Association (headed by Seiichiro Uda) was established, for purposes of coordinating purchases of mother mussels, and joint promotion and sale of products.

1951 (Showa 26) Gyokuryu Sakai establishes Nippon Shinjusha Co. Ltd. Cultivation begins in Shimono, Tokiwa Village, Kurita District, Shiga Prefecture.

1952 (Showa 27) A commercial pearl farming experiment was begun at Lake Suwa using mussels (Cristaria plicata) from the same lake.

1953 (Showa 28) Omi Railway Co., Ltd. began pearl farming at Katsuno Otomegaike, Takashima Town, Takashima District, Shiga Prefecture.

1953-1954 (Showa 28-29) Two organizations, the Kasumigaura Kitaura Pearl Cultivation Association and the Japan Pearl Research Institute, started pearl farming with Cristaria plicata in Sugai. In less than a year, a large number of mother mussels died and the business failed.

{This mussel (Kwong 光)was used in most Chinese cultivation in the 1960's and early 70's, producing the typical textured "rice crispies" in as little as one year.  Farmers gradually abandoned it in favor of the "Sam Kwok 三角形" triangular Hieryopsis cumingii, a native of the same genus as the less tolerant schlegeli.  Many hybrids are in use now, while the Cristaria plicata, which can live longer and grow larger, is hunted for shell and provides various quantities on seed pearls, too tiny to cultivate.}

1954 (Showa 29) Takeharu Jimbo begins pearl farming at Ukai Marsh in Obama, Moriyama-cho, Yasu-gun, Shiga Prefecture. Eishiro Sawano, Masao Yamaguchi, and others cultivated mother molluscs in Akita, Yamagata, and Aomori, using white clams (Spisula solida) and tagai (rice-paddy clams, Sinanodonta japonica).

1955 (Showa 30) Choshi Chojiro establishes Choshin Pearl Joint Stock Company, which is located in Uchiko, Imazu Town, Takashima District, Shiga Prefecture. Started bead farming. The Hokkaido Pearl Culture and Fisheries Production Association conducted a commercialization trial using Kawashinju (Margaritifera leavis) clams from the Chitose River as mother oysters.

 1956 (Showa 31) Test conducted at Shinminato City Hall, Toyama Prefecture. Tests were conducted at Neyagawa Farm in Osaka. Masayo Fujita's Lake Biwa Pearl Company was dissolved due to poor business management. The Shiga Prefectural Federation of Fisheries Cooperatives took over this initiative, formulated the "Basic Policy for the Promotion of Freshwater Pearl Cultivation Business", and began enlisting members in an effort to promote and nurture the industry, but the following year the company suffered poor business once again and was disbanded.

1957 (Showa 32) Shingo Tanaka established Shiga Prefecture Pearl Industry Co., Ltd. and takes over the Pearl Cultivation Department of the Prefectural Federation of Fisheries Cooperatives. The prefectural fish cooperative federation's pearl business was discontinued after just over a year.

1958 (Showa 33) and 1959 (Showa 34), 29  companies that had already started the pearl business were officially issued with fishing licenses for pearl farming.

1959 (Showa 34) Shiga Prefecture Pearl Cultivation Fisheries Cooperative Association (Council President Seiichi Yanagimori) was established. 30 members, with combined yield of 260 kan (975kg, nearly a ton), 907,000 treated shellfish, 222 operators. Shiga Prefecture revised the "Basic Policy for the Promotion of Freshwater Pearl Cultivation Business", established in 1955, replacing it with a new "Basic Policy for the Development of the Pearl Cultivation Industry." The 29 licensed pearl culture fisheries operators and those scheduled to receive licenses in 1960, and members of the freshwater pearl culture cooperative convened to dissolve the Shiga Prefecture Freshwater Pearl Culture Cooperative and established the Shiga Prefecture Pearl Cultivation and Fishery Cooperative (headed by Seiichi Nagayanagi Mori).

1960 (Showa 35) The Shizuoka Prefecture Fisheries Experiment Station conducted tests at eel ponds. The Shiga Prefecture Agriculture and Forestry Department has formulated the "Current status and strategy for the Shiga prefecture fisheries industry" to promote the pearl industry.

1962 (Showa 37) Production begins at Kasumigaura (Ibaraki Prefecture).

{Due the scarcity (caused by overfishing)  of Ikechogai (Hieryopsis schlegeli) in Lake Biwa, the mussels were being taken there. They were in high demand. One anecdote relates that transporters made so much money on the sale of a truckload that they returned with a new truck.}    

1963 (Showa 38) Shiga Prefecture further partially revised its "Basic Policy on the Development of Pearl Cultivation Industry". Ibaraki Prefecture Pearl Cultivation Fisheries Cooperative Association established (chairman: Takashi Toda *).

1964 (Showa 39) In order to improve the pearl distribution system, processing pearls and selling products, Shiga Prefectural Pearl Processing Cooperative Association (Chairman Kiyoshi Uratani) was established.

1965 (Showa 40) With the rapid development of the pearl industry, the shortage of mother oysters became serious, and the Federal Fisheries Agency's policy director invited industry representatives from Shiga, Fukui, and Ibaraki Prefectures, to form a cooperative (communicative) association to promote freshwater pearl cultivation and coordinate supply and demand of mother mussels. was established (headed by Shigeo Matsuda). Supplies of artificially bred mother mollusks began to replace hitherto used natural mother mollusks (gathered at adult stage).

1969 (Showa 44) In order to respond to the comprehensive development of Lake Biwa, an internal organization of the Shiga Prefecture Pearl Culture and Fisheries Cooperative Association was established. The Lake Biwa Water Level Drop Countermeasures Committee (later renamed the Lake Biwa Comprehensive Development Pearl Strategies Committee) established.

1971 (Showa 46) Freshwater cultured pearls from China appear on the Japanese market for the first time (160 momme= 600g). The artificial seedling collection method for Ikechōgai was patented by Shiga Prefecture as the applicant and Toshiki Suetomi and others as the inventors. (Toku-ko = Patent Office Publication Showa 46-23023).

1972 (Showa 47) Lake Biwa Comprehensive Development Project begins.

1978 (Showa 53) Import volume of freshwater pearls from China reached 2,600 kan = 9,750kg almost 10 tons, exceeding domestic freshwater pearl production. Method for artificially collecting spat of Ikechōgai was patented (Patent Office Publication Showa 53-3823), with Shiga Prefecture as the applicant and Keiichi Awano and others as the inventors.

1979 (Showa 54) Lake Biwa pearl culture industry friendship visit group toured freshwater pearl farms in China.

1980 (Showa 55) Domestic production reached its peak (1,690 kan = 6,337.5kg, 6 Tons).

1983 (Showa 58) Imports of freshwater pearls from China, including those via Hong Kong and India, reached 9,000 kan = 33,750kg = 33 Tons.

1984 (Showa 59) Due to deterioration of fishing grounds caused by illegal overcrowding, and increased mortality of mussels weakened by inbreeding, (Japanese) production plummeted.

{according to informed sources in Ibaragi, who also blame runoff from agricultural chemicals, it essentially ceased}

The amount of Chinese pearls exported from Japan reached its peak (13,000 kan = 48,750 = 48T).

In 1992 (Heisei 4), the Japan production volume was 66 kan = 247.5kg !!*, which was 3.4% of the peak production level.

1993 (Heisei 5), domestic production decreased drastically (36 kan = 135kg !!*).

{!!* These last 2 lines are difficult to believe, given the 2 preceding}

Source: Kazumasa Hayashi "Pearl farming in Lake Biwa" P 1-5 Shiga Prefecture Pearl Farming Fisheries Cooperative Association 1971 {The sources for post-1971 entries are not given.}

The following entries are from other sources. 1994 (Heisei 6) Kazuhisa Yanase, a cultivator in the Kasumi-ga-Ura area, harvested his first crop after a 10-year hiatus. The volume fit into two hands, and probably weighed less than 500 grams.

2001 (Heisei 13) Kazuhisa Yanase, frustrated by bureaucrats' slowness to act on permit applications for cultivation sites, nearly became the first man to cultivate pearls in an artificial pond.

2003 (Heisei 15) An outbreak of Herpes affecting koi (carp) decimated the population of these fish, and many other freshwater fish, eels, and mussels were also affected. The loss of mussels under pearl cultivation in the Kasumi-ga-Ura was not total, but mainly affected those with sub-ideal placement of the nucleus, leading to a scarcity of baroque shapes, which as a rule have more vibrant colors. Previously viable cultivations site became unusable.

2010 marked the debut of in-body bead nucleated bead nucleated pearls admittedly from China. Though we were aware of China production of IBN FW pearls at least from the mid 1980's, most vendors stated (and some probably believed) they all came from Japan, but this year the yield was so great that that transparent ruse had to be dropped. The exception was the brand name owners who probably do so now, in the absence of any Japanese production.

Very soon, Chinese brands emerged and achieved various degrees of success in confusing people to use their brands in lieu of a generic name for this product. At a lecture I attended in 2023 GIA pearl experts not only used a brand name to describe Chinese IBN freshwater pearls, but credited its owner as the "inventor". I pointed out both mistakes.


2011 (Heisei 15) There was an earthquake which destroyed water pipes in Ibaragi Prefecture, so that many people had to carry their water from trucks for months. It also destroyed breeding pools on which (all three active) cultivators in the Kasumi-ga-Ura area depended for mussels.


* individuals named are mentioned elswhere in info pages.