氯硝柳胺加地膜覆盖技术灭螺对鱼毒性的观察

目的观察氯硝柳胺加地膜覆盖灭螺技术对鱼类毒性的影响。方法选择1条有螺沟渠作为试验现场,分设对照组和灭螺组。灭螺组截流后采用50%氯硝柳胺乙醇胺盐可湿性粉剂按2 g/m2的剂量喷洒,然后覆盖地膜（覆膜）通水,对照组不采取任何灭螺措施。分别在现场和实验室观察流水及静水环境下鱼苗的死亡情况。结果在流水环境下,施药覆膜后7 d内灭螺组和对照组鱼苗死亡率差异无统计学意义（P=0.680）,揭去地膜（揭膜）后4 d两组均未出现鱼苗死亡;覆膜后7 d内灭螺组下游50、100、150 m 3个投放点与对照组鱼苗死亡率差异无统计学意义（P=0.955）,而揭膜后4 d内亦未发现鱼苗死亡。静水环境下灭螺组和对照组鱼苗死亡率差异无统计学意义（P=0.376）。灭螺组灭螺后钉螺死亡率为96.77%,对照组为0（P〈0.01）。结论氯硝柳胺加地膜覆盖灭螺技术既可提高灭螺效果,又可有效避免灭螺药物对鱼类等的毒性影响,是一种适用于鱼塘等特殊环境的灭螺方法。

Toxicity of niclosamide with plastic film mulching to fish

Objective To observe the toxicity of niclosamide with plastic film mulching to fish.Methods A ditch with Oncomelania snails was selected as the study site,and it was divided into a control group and a molluscicide group.After the river closure,the molluscicidal group was sprayed with niclosamide with a dosage of 2 g/m2,and then covered with plastic film;no molluscicide measure was implemented in the control group.The toxicity of the molluscicide to carp fish in resting and flowing water environment was obse...