长江下游润洲段洲滩湿地钉螺分布和对策研究

Study on distribution and countermeasures of Oncomelania snails in beach wetlands of Runzhou section of lower reaches of Yangtze River

目的了解长江下游洲滩湿地和钉螺分布情况,探讨洲滩湿地钉螺控制对策。方法现场调查长江润洲段主江堤外洲滩湿地分布,并按照我国湿地分级式分类系统进行湿地分类;调查2004-2013年润洲段沿江洲滩湿地钉螺面积、钉螺密度及灭螺资料,分析沿江洲滩湿地钉螺消长趋势。结果长江下游润洲段洲滩属河流湿地,除永久性水域外,历史上均有钉螺孳生。现有自然湿地1 303.0 hm2,人工湿地1 479.0 hm2,功能改变为非湿地1 059.0 hm2;2013年查出钉螺面积181.40 hm2,均分布于自然湿地。2004-2013年共计开展药物灭螺和环境改造4 624.55 hm2,钉螺面积和钉螺密度下降率分别为66.53%和77.66%。现有钉螺均分布于自然湿地。结论人工湿地有助于钉螺控制,沿江洲滩湿地钉螺控制必须重视湿地生态保护。

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.