不同鱼类对沉水植物生长的影响

沉水植物是富营养水体生态修复的重要组成部分,鱼类是影响沉水植物生长的重要因素之一.为了解鱼类对沉水植物生长的影响,研究3种鱼(草鱼(Ctenopharyngodon idellus)、鲫(Carassius auratus)、鳊(Parabramis pekinensis))对4种沉水植物(苦草(Vallisneria natans)、金鱼藻(Ceratophyllum demersum)、伊乐藻(Elodea nuttalli)、马来眼子菜(Potamogeton malaianus))生长的影响.结果显示,对照组、草鱼组和鳊组沉水植物生物量分别下降19.2%、82.1%和16.6%,而鲫组沉水植物生物量却增长12.5%.4种沉水植物中,金鱼藻生物量增长最高,其中对照组、鳊组和鲫组中金鱼藻生物量分别增长171.1%、113.9%和265.5%,而草鱼组金鱼藻生物量却下降24.4%.草鱼、鳊、鲫都能有效抑制沉水植物的竞争者水绵的生长.该研究结果在利用沉水植物修复富营养水体过程中对鱼类的管理具有重要的参考意义.

The effects of different fish species on growth of submerged macrophytes

Submerged macrophyte is an important component in ecological restoration of eutrophic waters. Fish is one of the important factors affecting the growth of submerged macrophytes. In the present study, the effects of three fish species(Ctenopharyngodon idellus, Parabramis pekinensis and Carassius auratus) on growth of four submerged macrophytes(Vallisneria natans,Ceratophyllum demersum,Elodea nuttalli and Potamogeton malaianus) were studied. Results showed that the decline rates of submerged macrophytes biomass were 19.2%, 82.1% and 16.6% in controls, C. idellus and P. pekinensis, respectively. However, submerged macrophytes biomass increased 12.5% in the C. auratus treatments. The rate of increase of Ceratophyllum demersum biomss was the highest among the four submerged macrophytes. The rate of increase of C. demersum biomass in controls,P. pekinensis and C. auratus treatments were 171.1%,113.9% and 265.5%, respectively, but that was -24.4% in C. idellus treatments. Moreover, all the three fish species inhibited the growth of Spirogyra which is one of the competitors of submerged macrophytes. The results of this study could be used for the fish management during the restoration of submerged macrophytes in eutrophic waters.