"Lake Suwa Pearl" No. 1.

Use the bivalve Hyriopsis there is a function of the water purification, Suwa area of environmental organizations "Lake Suwa Club" to work on pearl farming in Lake Suwa is, until the 9th small pearl is two some of the inside of the shell that was brought up in the lake i got you. 2011 since the start of the farming year, the first time the pearl is confirmed. It's both diameter 3-4 mm and small, but Miyahara Associate Professor of Shinshu mountain science laboratory was responsible for the experiment are pleased with the "plan was a step forward." Lake Suwa Pearl "No. 1 was able to."
Hyriopsis the endemic species of Lake Biwa water system. Purification capacity is high, and is also used for mother shellfish freshwater pearl farming. In Lake Suwa, while promoting the purification of the lake, draw a concept such as blending the resulting pearl in cosmetics, start farming in '11. In the shell, and released such as to preserve in the lake on you turn on the part of the body of shellfish to become the nucleus of the pearl. Now I have brought up the more than 60 individuals.
This pearl, there was one by one in the two shells that have been raised from March 11. Early December last year, where it had been the work of cycling the nucleus to shellfish, by chance discovery. Work, because the shell does not open as much as possible the shell so as not to Shimawa weak, that addition to there is a possibility of finding a shellfish that could pearl.
However, one of the shellfish pearl is found, died in late December last year. For the time being I watch or another pearl increases. Will continue to farming other shellfish are at least three years, from time to time when the dead, confirm the presence or absence of a pearl.
According to the Miyahara Associate Professor, but to increase the pearl's essential growth of shellfish itself, shellfish pearl is found this time, did not become only big 1-2 cm in 3 Toshi-yo from aquaculture start. Usually freshwater pearl farming in 3-4 years, will be referred to as need more long time in Lake Suwa, such as securing of plankton that becomes the prey is likely to challenge the future.
Miyahara Associate Professor are referred to as "the time being, but well pearl was cooked. Take time to farming, want to continue the research so that it is the symbol of Lake Suwa". It seems possible to interesting initiatives and pearls will be able to production in Lake Suwa along with the water purification.



水質浄化の働きがある二枚貝イケチョウガイを使い、諏訪湖で真珠養殖に取り組む諏訪地域の環境団体「諏訪湖クラブ」が、湖で育てた貝の中に小さな真珠が二つあるのを９日までに見つけた。２０１１年の養殖開始以来、真珠が確認されるのは初めて。共に直径３～４ミリと小粒だが、実験を担当した信州大山岳科学研究所の宮原准教授は「計画が一歩前進した。『諏訪湖パール』第１号ができた」と喜んでいる。
　イケチョウガイは琵琶湖水系の固有種。浄化能力が高く、淡水真珠養殖の母貝にも使われる。諏訪湖では、湖水の浄化を進めつつ、得られた真珠を化粧品に配合するなどの構想を描き、１１年に養殖がスタート。貝の中に、真珠の核になる貝の身の一部を入れた上で湖内のいけすなどに放流。現在は６０余の個体を育てている。
　今回の真珠は、１１年３月から育ててきた二つの貝の中に一つずつあった。昨年１２月上旬、貝に核を入れ直す作業をしていたところ、たまたま発見。作業は、貝が弱ってしまわないよう殻を極力開かないため、ほかにも真珠ができた貝が見つかる可能性があるという。
　ただ、真珠が見つかった貝のうち一つは、昨年１２月下旬に死んでしまった。当面はもう一つの真珠が大きくなるか見守る。ほかの貝は少なくとも３年間は養殖を続け、死んだ時点で随時、真珠の有無を確かめる。
　宮原准教授によると、真珠を大きくするには貝自体の成長が不可欠だが、今回真珠が見つかった貝は、養殖開始から３年余で１～２センチしか大きくなっていなかった。通常の淡水真珠養殖は３～４年で、諏訪湖ではもっと長い時間が必要といい、今後は餌となるプランクトンの確保などが課題になりそうだ。
　宮原准教授は「ひとまず、よく真珠をつくってくれた。養殖に時間がかかるが、諏訪湖のシンボルになるよう研究を続けたい」としている。水質浄化に伴って諏訪湖に真珠が生産できるようになると面白い取り組みができそうですね。