不同放苗密度凡纳滨对虾生物絮团养殖的环境和产出效应

本研究尝试将生物絮团养殖技术(Bio-floc aquaculture technology, BFA)应用到凡纳滨对虾高密度养殖系统中，研究生物絮团在凡纳滨对虾不同放苗密度下的水质调控、对虾生长及存活等方面的作用效果。试验将200、400和600尾/m2的放苗密度分为传统养殖组(TF200、TF400和TF600)和絮团养殖组(BFA)(BF200、BF400和BF600)共6组，分别在18个室内水泥池中进行，其中BFA组通过添加益生菌和赤砂糖培养生物絮团，并在养殖过程中极少换水，而传统养殖组进行传统换水养殖管理。经过113d的养殖试验，随着放苗密度的增加，水质、对虾存活率和对虾特定增长率逐步下降，然而BFA在400尾/m2的凡纳滨对虾封闭式养殖中有良好效果。与400尾/m2的传统养殖组(TF400)相比，400尾/m2的BFA组(BF400)在养殖过程中生物絮团平均形成量提升3.25倍；水体中的亚硝酸氮和氨氮平均含量分别降低67.9%和72.7%，而用水量只有传统养殖组的33%左右；对虾的体重、存活率、特定生长率及单位产量分别提高了14.5%、156.3%、2.4%和194.1%；400 尾/m2的BFA组对虾单位产量达到4.01±0.94 kg/m2，具有最好的环境和产出效应。

The environmental and production effect of bio-floc aquaculture of Litopenaeus vannamei at different stocking densities

A 113-day experiment was conducted to investigate the efficiency of bio-floc aquaculture technology (BFA) for water quality control, disease resistance and growth of Litopenaeus vannamei in intensive farming systems at different stocking densities. The experiment was carried out on traditional farming treatments (TF200, TF400, and TF600) and BFA farming treatments (BF200, BF400, and BF600) at stocking densities of 200, 400 and 600 ind/m2, respectively. The six groups of shrimp were kept in 18 indoor cement tanks. Bio-flocs were developed in BFA farming tanks by adding sucrose and probiotic with very little water exchange during the experiment. Traditional farming treatments were cultured with traditional methods. It was found that the water quality, special growth rate and survival rate of the shrimp deteriorated or reduced with the increase of stocking density in all treatments. However, BFA at stocking density of 400 ind/m2 revealed advantage in closed farming systems of L. vannamei, compared with the traditional farming at the same stocking density (TF400). In BF400, the bio-floc volume increased by 3.25-fold, while the concentrations of nitrite-N and ammonia-N decreased by 67.9% and 72.7%, respectively; Water consumption decreased about 33%, and body weight, survival, special growth rate and production per unit of L. vannamei increased by 14.5%, 156.3%, 2.4%, and 194.1%, respectively. The production of BFA farming at stocking density of 400 ind/m2 (BF400) was 4.01±0.94 kg/m2, showing the best environmental and production effect.