光照条件下生物絮凝养殖调控的措施

运用实验生态学的方法,以阳光工厂化生物絮凝养殖前期水为实验材料,分别探究去细菌捕食者(原生动物等,AC组)、带虾序批添加葡萄糖(GS组)和一次性添加葡萄糖(G组)对水中微食物环的细菌及浮游生物的影响。结果表明,GS组在120 h的轮虫生物量、浮游植物生物量和叶绿素a含量都显著高于对照组(P0. 05)和而G组的轮虫生物量、浮游植物生物量在整个实验过程中与对照组无显著性差异(P 0. 05),因此序批式添加葡萄糖的上行效应比一次性添加更加明显,并且添加大型捕食者的GS组的下行效应不明显。实验组和对照组细菌总数都大于5×10~5个/mL,AC组的细菌总数峰值最高[(13. 10±3. 79)×10~5个/mL],去细菌捕食者后降低了对细菌的捕食压力从而促进了细菌生长。AC组的溶解性有机碳浓度和溶解性总氮浓度一直高于其他组,GS组、G组和对照组的溶解性有机碳、溶解性总氮和磷酸盐浓度的变化趋势基本一致,杀死细菌捕食者释放了大量溶解性有机物,添加适量葡萄糖、投放虾对养殖水质无明显影响。研究结果为阳光型生物絮凝养殖在生产应用上的调控手段提供基础依据。

Control measures of biofloc-technology aquaculture under light condition

By using the method of experimental ecology, the water in the early stage of BFT aquaculture was used as the experimental material.The effects of bacteria free predators (protozoa etc., group AC), group with shrimp order supplemented with glucose (group GS) and single dose of glucose (group G) on bacteria and plankton in water were investigated. The results show that the biomass of rotifer, phytoplankton and concentration of chlorophyll-a in group GS were significantly higher than those in control group (P<0.05) in 120 h, while the biomass of rotifer and the phytoplankton in the group G had no significant difference from the control group (P>0.05) during the whole experiment (P>0.05), so the bottom-up effect of the sequential batch addition of glucose was more obvious than that of the one-off addition, and the top-down effect of group GS with large predators was not obvious. The total number of bacteria in the experimental group and the control group was higher than 5×10⁵ cells/mL. The highest peak number of bacteria was (13.10±3.79)×10⁵ cells/mL in group AC, which reduced the predation pressure on the bacteria and promoted the growth of the bacteria after removing the bacterial predator. The dissolved organic carbon concentration and dissolved total nitrogen concentration in the group AC were always higher than those of other groups. In the group GS, group G and the control group, the concentrations of dissolved organic carbon, total dissolved nitrogen and phosphate were basically consistent.Killing bacterial predator released a large amount of dissolved organic matter, adding appropriate amount of glucose, and adding shrimp had no obvious effect on the water quality of culture. Killing bacterial predator released a large amount of dissolved organic matter. Adding appropriate amount of glucose and adding shrimp had no obvious effect on the water quality of culture. The results provide the basis for control measures on sunshine biofloc-technology aquaculture in production.