降低中华绒螯蟹体内镉含量的安全养殖模式研究

A Safe Culture Model for Reducing Cadmium Content in Chinese Mitten Handed Crab Eriocheir sinensis

为探讨降低该地区存在的养殖河蟹Eriocheir sinensis体内重金属镉含量超标问题,根据河蟹污染的溯源分析,通过改变河蟹不同养殖阶段的饵料(螺蛳、小杂鱼等)结构,调整饲养模式(网箱养殖),降低河蟹体内Cd含量,确保其Cd含量符合国家标准。本文的安全养殖模式为:1—2月大湖养殖,每667m2投放100~200只/kg的长江系幼蟹2 kg;1—4月投喂螺蛳,4月兼投少量小杂鱼,5—11月投喂小杂鱼;1—8月自然水底养殖;9—11月期间,在上市前1个月进行网箱养殖。2016年和2017年跟踪监测显示:该模式养殖的河蟹体内Cd含量均符合国家标准。

The food type(snails,and small fish)and feeding regime(temporary cage culture)were changed and adjusted to reduce the excessive content of heavy metal cadmium in Chinese mitten handed crab(Eriocheir sinensis)during various culture period according to the traceability analysis of the crab pollution to reduce the cadmium content in Chinese mitten handed crab,that is,the Cd content in the crab is within the national standard.In the safe cultivation model,Chinese mitten handed crab juveniles with body weight of 100~200 individuals/kg from Yangtze River strain were reared in a large lake at a stocking density of 2 kg per 667 m2,and fed snails from January to April,addition of small miscellaneous fish in April and small miscellaneous fish from May to November.One-month cage culture was carried out before Chinese mitten handed crab was harvested for market.The Cd monitoring analysis in2016 and 2017 revealed that the Cd content in Chinese mitten handed crab cultured in the model met the national standard requirement.