引用本文: | 郭晓鸣,高光,魏云,周万平.伊乐藻-草鱼圈养复合生态系统中水生生物的变化和影响.湖泊科学,1996,8(Z1):79-92. DOI:10.18307/1996.sup10 |
| Guo Xiaoming,Gao Guang,Wei Yun,Zhou Wanping.Changes and effects of hydrobios in the compound ecosystem of Elodea-grass carp pen farming. J. Lake Sci.1996,8(Z1):79-92. DOI:10.18307/1996.sup10 |
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摘要: |
从细菌、浮游植物、浮游动物、底栖动物和有机碎屑等几个方面分析了养鱼对伊乐藻种植区(以下简称为有草区)和无草区水域环境的影响。结果表明:两个区域存在着显著的差异性。有草区由于生长着茂密的水生植被,对环境压迫的缓冲能力增强,水生生物的群落结构较为稳定,物种多样性指数高于无草区,有机物的沉降速率也大大低于无草区。与此相比,无草区对环境压迫的缓冲能力较差,水体浮游植物数量增加,富营养化加剧。通过本项实验可以看出,人工种植伊乐藻对养鱼区水质有着明显地控制作用,是发展生态渔业的一条有效途径。 |
关键词: 伊乐藻 养鱼 环境影响 浮游植物 游游动物 底栖动物 |
DOI:10.18307/1996.sup10 |
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Changes and effects of hydrobios in the compound ecosystem of Elodea-grass carp pen farming |
Guo Xiaoming, Gao Guang, Wei Yun, Zhou Wanping
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Nanjing Institute of Geograghy and Limnology, Chinese Academy of Sciences, Nanjing 210008
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Abstract: |
Elodea-grass carp pen farming is a relatively independent subsystem artificially established in the lake, in which the grass carp feeds on Elodea Nattallii, the excretory matters of fish transform into nutrient salts, and nutrient salts transform into the circulatory system of Elodea. The transformed organic matters are moved out of the system through fish and there are no extra organic matters remained in the system, so fish-farming environment is optimized. Based on the above-mentioned, we selected East Taihu lake as the experiment base and established a semi-closed experiment region, in which there are two fish-farming districts, Elodea-growing district and no-weed district. The changes of bacteria, phytoplankton, zooplankton, zoobenthos and organic detritus have been analysed. The results show:(1) The density of heterotrophic bacteria decreases gradually from fish-farming district to outside, decrease 88.9% in Elodea-growing district and 73.9% in no-weed district. The amount of coliform group is similar to heterotrophic bacteria, decreases 75.3% and 66.7% respectively in both districts. (2) The average density and biomass of phytoplankton are 4 612.187×104 ind./L and 7.1776mg/L in Elodea-growing district and 6070.853×104 ind./L and 8.3108mg/L in no-weed district respentively.(3) 92 and 60 species of zooplankton (including Rotifera, Cladocera and Copepoda) have been found in Eiodea-gvoWmg and no-weed district, respectively. The average density and biomass are 4 752 ind./L and 4.868mg/L and 6 749 ind./Land 3.9407mg/L respectively. (4) 19 and 14 species of zoobenthos (including Annelida, Mollusca and Arthropoda) have been found respectively in the two districts. Although the densities are the same in two districts, the compositions of community and biomass are different. The average density and biomass of Annelida (mainly oligochaete) are 59 ind./m2 and 0.575mg/m2, 73 ind./m2 and L 453mg/m2; Mollusca are 80 ind./m2 and 34.822mg/m2, 29 ind./m2 and 12.065mg/m2; Arthropoda(mainly chironomid larvae) are 78 ind./m2 and 0.673mg/m2, 115 ind./m2 and 0.688mg/m2 in two districts respectively. (5) According to the average depositional rate of organic matters, it is as 5 times in no-weed district as that in Elodea-growing district. Due to the macrophyte, the buffer capacity effected by environment is strengthened in the Eoldea-growing district. Not only is the water body purified and the water quality recovered. but also the community structure of hydrobios is more stable and species diversity is increased. Eutrophication is also controlled effectively. So, Elodea-grass carp pen farming is a optimum way of eco-fishery development. |
Key words: Elodea Nuttallii fish-farming environment consequence bacteria phytoplankton zooplankton zoobenthos organic detritus |