中层取水拦螺网用于电灌站防螺的效果观察

Field observation of the effectiveness of stopping the dispersion of Oncomelania snails at an electric pumping station through the use of snail nets at mid-water level

目的评价中层取水拦螺网用于电灌站防螺的效果。方法在有螺河道肖梁河取水的王庄电灌站进水口设置中层取水拦螺网,用常规法对电灌站水源河道和灌区沟渠进行钉螺调查。对有螺水源河道和灌区有螺环境进行药物灭螺。根据钉螺面积和钉螺密度变化进行防螺效果评价。结果 2006～2011年肖梁河每年均查出钉螺,钉螺面积和钉螺密度呈显著正相关(r=0.972,P<0.01),并呈下降趋势。王庄电灌站设置中层取水拦螺网之前每年均查出钉螺,有螺面积与钉螺密度呈正相关(r=1.000,P<0.01);设置中层取水拦螺网后灌渠即未查出钉螺。结论在有钉螺扩散风险的电灌站设置中层取水拦螺网结合药物灭螺是简便有效的防控钉螺扩散模式。

Objective To evaluate the effectiveness of stopping the dispersion of Oncomelania snails using snail nets at mid-water level at an electric pumping station.Methods Snail nets at mid-water level were set up at the water inlet of the Wangzhuang electric pumping station,which is located on the Xiaoliang River where snails are present.The conventional method was used to survey snails in the river supplying the electric pumping station and irrigation ditches.Snails in the river and the ditches were killed with a molluscicide.The effectiveness of stopping the dispersion of snails was evaluated according to changes in the area inhabited by and density of snails.Results Snails were detected in Xiaoliang River from 2006 to 2011.The snail area and density were positively correlated（r=0.972,P〈0.01）.The snail area and density in the river tended to decrease.Before Wangzhuang electric pumping station installed snail nets,snails were detected every year,and the snail area and density were positively correlated from 2006 to 2009（r=1.000,P〈0.01）.However,snails were not detected in irrigation ditches after the snail nets were set up.Conclusion Use of snail nets at mid-water level along with a molluscicide is a simple and effective method of controlling snails at electric pumping stations where snails may spread.