Jusanko san Yamato Shijimi

　Jusankosan Yamato Shijimi is a Yamato shijimi clam raised in Lake Jusanko in Aomori Prefecture. It is blessed with an excellent growth environment due to its salinity, dissolved oxygen content, sediment quality, and spawning conditions.

　It is highly appreciated on the market not only because of its tasty dashi stock and high quality, but also its steady shipment rate throughout the year. The best season for Shijimi is during the spawning season in July and August when the body grows larger and succulent juices develop. In winter, the flesh tightens, the flavor intensifies, and it is sold as winter shijimi.

　In the local area, it has long been loved as a special product, and in Goshogawara City, Aomori Prefecture, it is called "the shellfish of the city". It is eaten as ramen, soup or butter stir-fry; and is also sold as processed food such as frozen shijimi, an extract or a powder. There is high demand both within and outside the prefecture.

　Yamato shijimi are harvested by dredging the bottom of the lake using fishing nets with a mesh of 12 mm or more. The catch is sorted by a machine or carefully sieved in the fishing net so as to release shijimi that are less than the minimum size of shipping standard. Dead shellfish are carefully removed by their appearance and sound, and the product is separated into different grades.

　Lake Jusanko is a shallow brackish water lake with a depth of only one meter located in the most downstream part of the Iwaki River that originates in the Shirakami Mountains, a World Natural Heritage site. From there, it flows through the Tsugaru Plain and into the Sea of Japan. Throughout the year, it has a suitable salt environment and a sandy sediment with less than fifty percent mud; and maintains the amount of dissolved oxygen at 3.5 mg/ℓ which is the minimum necessary to live.

　The history of Jusankosan Yamato Shijimi is long, and the shijimi catch in Lake Jusanko is listed in fishery survey data of Aomori Prefecture of 1891. Since the 1980's, restrictions such as operating period, area, and catch amount have been put in place based on the results of yearly resource surveys conducted by research institutes. Also, even during the winter season when the lake has fishing restrictions or freezes over, shijimi caught during the fishing season are transplanted to individual controlled areas and farmed for stable shipment throughout the year.