生物操纵方法对水绵(Spirogyra)的调控效应

为探究安全高效调控水绵生长的方法,本研究利用养殖水桶开展了两次生物操纵实验,分别观测了鲤(Cyprinus carpio)、鲫(Carassius auratus)和鲢(Hypophthalmichthys molitrix)在没有营养加富条件下,以及鲫和日本沼虾(Macrobrachium nipponense)在营养加富条件下,对水体中浮游态和固着态水绵(Spirogyra)生长的抑制效果.结果表明,在没有营养加富的水体中,鲤和鲫对水绵不仅没有调控效应,反而会促进水绵的生长.建议在水绵生长旺盛的水体中,一定程度上移除水体中这些鱼类反而可以有效控制水绵的生长.在营养加富条件下,日本沼虾对水绵的控制效应明显.鲫对水绵发挥的作用与水体营养状态存在交互作用,日本沼虾对水绵的抑制效应是否受水体营养状态的影响值得进一步探究.

Effects of biomanipulation control on Spirogyra

In order to explore the controlling effect on Spirogyra safely and efficiently, we conducted two biomanipulation experiments using buckets in this study. We observed the controlling effect of Cyprinus carpio, Cyprinus carpio, and Hypophthalmichthys molitrix on the planktonic and benthic Spirogyra without nutrients enrichment, and the controlling effect of Carassius auratus and Macrobrachium nipponense on the planktonic and benthic Spirogyra with nutrients enrichment. The results showed that Cyprinus carpio and Cyprinus carpio had no controlling effect on Spirogyra without nutrients enrichment, but promoted Spirogyra biomass instead. We suggest that removal of these fish from the water may be effective in controlling the Spirogyra growth in waters where it blooms. Under the condition of nutrients enrichment, the controlling effect of Macrobrachium nipponense on Spirogyra was obvious. There was an interaction between the effect of Cyprinus carpio and the eutrophic status on Spirogyra. Further studies need to explore whether the controlling effect of Macrobrachium nipponense on Spirogyra is affected by the eutrophic status.