Behavior of nuisance mussel, Limnoperna fortunei, in water supply facilities

Limnoperna fortunei, a species of bivalve of foreign origin, was confirmed to exist in Japan for the first time in 1992. It was found in some facilities of Hanshin Water Supply Authority in 1994. Later, it was found to cause various problems such as clogging of sampling pipes. Following this finding, research was initiated to investigate the possibility of its causing major incidents of bio-fouling such as total blockage of water passage by adhering to the raw water transmission pipe wall in massive numbers. As a result, it was found that Limnoperna fortunei was spawned in summer and grew up to 20 mm in size by the end of a one-year period when it began to die out and became detached immediately. Therefore, it was concluded that no deliberate efforts to remove them are required to avoid major problems.