1Soma Branch, Fukushima Prefectural Fisheries Experimental Station, Soma, Fukushima 976-0022, 2Graduate School of Life Science, Tohoku University, Sendai, Miyagi 980-8578, 3Department of Biological Engineering, Ishinomaki Senshu University, Ishinomaki, Miyagi 986-8580, Japan
The present study investigated temporal changes in the abundance of the nonindigenous moonsnail Euspira fortunei after its human-mediated introduction in Matsukawaura Lagoon, Fukushima, Japan. This species was first observed in May 2002 and thereafter expanded its habitat into almost the entire lagoon until 2004. We found this species mixed with the Manila clam Ruditapes philippinarum brought from other areas for release. The density of E. fortunei did not decrease from 2004 to 2010, indicating that extermination efforts should be intensified to reduce the population of this invasive species.