Abstract: Objective To understand whether the Oncomelania hupensis in the Yangtze River can be spread to water receiving areas in Shandong Province through the eastern route of the South-to-North Water Diversion Project. Methods Monitoring points were set up at Hanzhuang Ship Lock in Weishan County from 2014 to 2018. Snail prevalence was monitored around the bottomland of the lock once a year in April. From May to October of each year, 2 to 3 ships from the Yangtze River were randomly chosen, once a month at the ship lock, to receive inspection of snails that were collected and identified for the species. Results Between 2014 and 2018, Oncomelania hupensis prevalence was investigated in spring seasons in
a total of 8 000 m length of the bottomland, with an accumulative areas of 15 880 m² and 1 515 frames (0. 11m² / frame), No snail was found. Fifty-one heads of snails were captured in sampling inspection of the 63 ships, and identified just as freshwater snails instead of Oncomelania hupensis. Conclusion No imported Oncomelania hupensis was found at Hanzhuang Ship Lock in Weishan Lake area in the past 5 years after completion and operation of the water diversion project. However, some freshwater snails were carried with ships from the Yangtze River, which should call our attention.

Key words: Oncomelania hupensis, South-to-North Water Diversion Project, Monitoring, Weishang Lake area