Study on distribution and countermeasures of Oncomelania snails in beach wetlands of Runzhou section of lower reaches of Yangtze River / 中国血吸虫病防治杂志

ABSTRACT

Objective To understand the distribution of the river beach wetlands and Oncomelania snails in the lower reach-es of the Yangtze River,and explore the countermeasures of snail control. Methods The river beach wetlands outside the Yang-tze River levee were investigated and classified according to the hierarchical and classification system of wetlands of China. The snail survey was carried out in the beach wetlands of Runzhou section of lower reaches of the Yangtze River from 2004 to 2013. The change trend of snail areas and the densities was analyzed in the wetlands. Results The river beach of Runzhou section of lower reaches of the Yangtze River belongs to the riverine wetland. There was Oncomelania snail breeding except the permanent wa-ter area. At present,there were natural wetlands of 1 303.0 hm2,human-made wetlands of 1 479.0 hm2 and wetland function chang-es of 1 059.0 hm2 in the river beach of Runzhou section. There was the snail area of 181.4 hm2 in the natural wetland in 2013. The area of snail control by the molluscicide and environmental modification was 4 624.55 hm2 from 2004 to 2013. The decline rates of snail areas and densities were 66.53%and 77.66%respectively. The existing Oncomelania snails were distributed in the natural wetlands. Conclusion The human-made wetland is helpful to snail control. The snail control in the river beach wetlands should attach a great importance to the protection of wetland ecology.