饲料投喂及清淤对养殖库湾水环境的影响

为探究缩减饲料投喂量及清淤对养殖库湾水环境的影响,在鲢、鳙放养密度均为20 g/m~3的基础上,设置4个处理组库湾,分别为B1(不清淤、饵料投喂减半)、B2(清淤、不投饵)、B3(清淤、饵料投喂减半)和B4(不清淤、饵料投喂正常),实验周期为9个月。结果显示:4个库湾的总氮浓度、总磷浓度、高锰酸盐指数、藻类生物量从低到高分别为B2、B4、B1、B3,B2、B1、B4、B3,B2、B1、B4、B3,B2、B1、B3、B4(P0.05),浮游动物生物量之间无显著性差异(P0.05)。由此可见,B2无论是在营养盐的控制还是在藻类的控制方面均取得了最佳的效果。作为养殖库湾,其主要功能是得到更高的鱼产量。在达到养殖水质要求的情况下,为了得到更高的鱼产量,应合理地利用饵料。因此,对于养殖用水的处理,要根据具体的水质条件,采用合理的修复方式,实现水质改善和养殖生产的双赢。

Effect of feeding and dredging on water environment in aquaculture bay

In order to investigate the effects of reducing feeding amount of bait and dredging on the water environment of aquaculture bay, the four treatment groups were set up on the basis of 20 g.m-3 stocking density of Silver carp and Bighead carp. They were B1 (no dredging, half feeding of bait), B2 (dredging, no feeding), B3 (dredging, half feeding of bait), B4 (no dredging, normal feeding of bait). The experimental period was 9 months. The results showed as follows:The total nitrogen concentration, total phosphorus concentration, permanganate index and algae biomass from low to high were B2, B4, B1, B3; B2, B1, B4, B3; B2, B1, B4, B3; B2, B1, B3, B4 (P < 0.05), respectively. There was no significant difference in zooplankton biomass (P > 0.05). This showed that B2 achieved the best results in both the control of nutrient salt and algae. As the aquaculture bay, its main function is to get higher fish production. Therefore, under the condition of meeting the requirements of aquaculture water quality, we should make rational use of the bait to obtain higher fish production. B3 has achieved good results in algae control. Therefore, for the treatment of aquaculture water, we should adopt reasonable repair methods according to the specific water quality conditions, in order to achieve a win-win situation of water quality improvement and aquaculture production.