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1.
伊乐藻,轮叶黑藻净化养鱼污水效果试验 总被引：27，自引：0，他引：27
在实验室条件下.对伊乐藻及轮叶黑藻净化养鱼污水的能力进行了比较研究。结果表明:(1)伊乐藻和轮叶黑藻对养鱼污水中的N、P等物质有较好的净化效果。在96h内,它们对TN、TP、PO_4~(3-)-P、NH_4~+-N、NO_3~--N、COD_(Mn)的平均净化率分别为:60.7％,53.6％.74.4％.59.7％,75.1％,63.2％;61.8％,54.2％.85.3％,81.8％,31.4％,33.5％。(2)水生植物在净化过程中,其效率受温度、光照、及水体中营养盐浓度等外界条件的制约。(3)微生物在水生植物净化养鱼污水的过程中起着重要的作用。 相似文献
2.
伊乐藻—草鱼圈养复合生态系统中水生生物的变化和影响 总被引：2，自引：1，他引：2
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。 相似文献
3.
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。 相似文献
4.
W. de L. Main 《新西兰海洋与淡水研究杂志》2013,47(1):15-38
The distributions of two swimming crabs endemic to the New Zealand region are described, mostly from material obtained at 118 of 2544 New Zealand Oceanographic Institute benthic stations sampled. Nectocarcinus antarcticus (Jacquinot) was found within the geographic limits 34°S‐51°S and 166° E‐176° W, with concentrations around Cook Strait, the Chatham Rise, Foveaux Strait, and the Auckland Is. N. bennetti (Takeda & Miyake) occurred between 44° S and 53° S, and 165° E and 180°, most frequently in the south and west, on the ‘highs’ of the Campbell Plateau. Although the distributions overlap between 44° S and 51° S, and this overlap zone produced most of the available material, only one joint occurrence of the two species was noted. This apparent separation was not satisfactorily explained by any of the ecological factors recorded. The depth ranges of both species were broadly similar (0–550 m for TV. antarcticus, 20–474 m for JV. bennetti); both were most frequently obtained at depths less than 200 m. Both occurred primarily on the coarser sediment grades, though N. antarcticus occupied a broader range of grades than N. bennetti. The size ranges of the two species were similar; carapace lengths were 8.0–62.0 mm for N. antarcticus and 5.8–68.0 mm for N. bennetti. The larger specimens of both species were found towards the southern limits of distribution. Larger specimens of N. antarcticus were absent from depths greater than 120 m; smaller N. antarcticus and all N. bennetti occurred throughout their respective depth ranges. Ovigerous N. antarcticus (smallest, 8.8 mm carapace length) were obtained at depths of 17–263 m from May to October; ovigerous N. bennetti (smallest 36.1 mm) were from depths of 150–183 m in May only. 相似文献
5.
环棱螺(Bellamya sp.)是太湖常见的一类软体动物.本研究通过室内实验,探讨环棱螺对轮叶黑藻(Hydrilla verticillata Royle)和伊乐藻(Elodea nuttalli ST John)生长的影响及水体营养盐含量的变化.结果表明,三种处理情况下,单位质量伊乐藻增加的数量分别为:H组0.475 g,L组0.106 g,C组0.021 g,单位质量轮叶黑藻增加的数量分别为:H组0.704 g,L组0.663 g,C组0.478 g.从实验前后两种沉水植物的长度和分蘖数变化来看,H组最高,L组与C组分别次之,所以不论生物量、长度还是分蘖数的变化量,与环棱螺共存的伊乐藻和轮叶黑藻的变化都高于对照组中两种沉水植物的变化.环棱螺新陈代谢促进水体中溶解态氮磷含量增加,三种情况下水生植物的初级生产力都相当,由此可推测环棱螺通过新陈代谢,一定程度上促进了两种沉水植物的生长. 相似文献
6.
Maryd De Wemton John S. Clayton Rohan D. S. Wells Chris C. Tanner Suzanne T. Miller 《新西兰海洋与淡水研究杂志》2013,47(2):145-151
The submerged vegetation of Lakes Sumner, Marion, Katrine, Taylor, and Sheppard was surveyed in May 1987. These high‐altitude lakes lie at c. 600 m a.s.l., within the largely unmodified upper Hurunui catchment. Submerged vegetation was diverse and included numerous short shallow‐water species, dense swards of Isoetes alpinus, low covers of taller native vascular plants, and charophyte meadows beyond the depth limit of vascular plants to a maximum of 15 m. A sparse deepwater bryophyte community was observed from 11 to 32 m depth in Lake Sumner. Displacement of native vegetation by dense growths of the adventive oxygen weed Elodea canadensis over mid‐depths of 3–6 m was noted in all lakes, except Lake Marion. 相似文献
7.
J. S. Claytont 《新西兰海洋与淡水研究杂志》2013,47(1):89-94
Fluctuations in water level and the growth of the introduced exotic Lagarosiphon major (Ridley) Moss have significantly influenced the submerged vegetation of Lake Rotoma over the period 1973–80. Low lake levels temporarily reduced the proportion of native vascular plants by removing available shallow‐water habitats through erosion, siltation, or desiccation. High lake levels have allowed native vascular plants to re‐establish from seed and rhizomes. Fluctuations in water level appear to have reduced the long‐term replacement of native species by L. major, which has none the less spread progressively around the lake. Water‐level fluctuations enhanced its rate of fragmentation, and thus its dispersal and establishment. The annual increase in the proportion of L. major has been primarily at the expense of the shallow‐water characean algae, but also partly by competitive displacement of native vascular plants. The southwest inlet of Lake Rotoma had an exceptionally high plant density, with up to 3518 g/m2 dry weight of L. major (believed to be a world record for submerged plant biomass); this is attributed to local enrichment and protection from wave exposure. 相似文献
8.
南京花神湖3种沉水植物表面附着微生物群落特征 总被引：5，自引：2，他引：3
沉水植物表面附着微生物系统是水生态的重要组成部分,然而当前对其了解仍不清楚.南京市花神湖是一个城市湖泊,沉水植物生长区域面积占湖面面积的40%左右.尽管花神湖的氮、磷营养盐水平很高,但最近未发生过藻类水华现象.本文以南京市花神湖中自然生长的优势种菹草(Potamogeton crispus)、伊乐藻(Elodea nuttallii)和金鱼藻(Ceratophyllum demersum)为研究对象,利用扫描电镜和荧光显微镜观测了叶表面附着微生物群落的分布特征,测定了植物表面附着微生物的密度及附生藻类的种类、密度和优势种群,并比较分析了不同水生植物之间附生藻类的差异性.结果表明,沉水植物表面微生物群落的分布与物种和叶龄有关.3种沉水植物中,菹草表面微生物群落结构最为复杂,微生境最为丰富.底部老叶片上面附着较多的微生物且表现出较高的生物多样性.植物表面附着微生物密度大小顺序为:菹草金鱼藻伊乐藻;植物表面附生藻类密度大小顺序为:菹草金鱼藻伊乐藻.总体来讲,沉水植物表面微生物总量大概比藻类数量高1~2个数量级.这为深入研究沉水植物及其表面微生物的生态功能奠定了基础. 相似文献
9.
通过人工围隔内伊乐藻种植区、无草区和围隔外湖区对照点的水质,底质定期观测,研究了伊乐藻对围栏养鱼环境的影响。结果表明:(1)围栏养鱼残饲和排泄物增加了水中N、P和COD含量,使DO与pH值降低,但伊乐藻对N的净化能力较强,使种植区TN和ION比无草区低14.5％和33.1％;(2)围栏养鱼对底泥的影响,无草区无明显变化,伊乐藻种植区养鱼前期N、P、C含量均低于本底值,养鱼后期有明显的增加趋势;(3)据N、P投入、输出计算,输出和迁移至伊乐藻与鱼体的大于投入的,计算表明,在伊乐藻生长旺季,养鱼与种植面积之比为1:3.58时,不会增加水中N、P含量。(4)养殖水体稀释扩散试验结果,在有草水体中围栏养殖水体对环境影响不大。 相似文献
10.
草鱼、团头鲂对伊乐藻的消化与利用 总被引：3，自引：2，他引：3
本文分析了伊乐藻的生化成分和能值,测定了草鱼、团头鲂对伊乐藻生化成分的消化率,草鱼对伊乐藻的最大摄食量、蛋白质利用率和饲料系数。结果表明,伊乐藻含水率为89.8％,干物质中粗蛋白质、粗脂肪、粗纤维素和无氮浸出物含量分别为23.52％、2.88％、26.71％和29.27％,含有17种常见氨基酸,总量为198.04mg/g(干重)。在平均水温20.4℃的室外条件下,草鱼,团头鲂对伊乐藻的干物质消化率分别为56.02％、54.97％,对粗蛋白质消化率分别为79.05％、74.96％,对氨基酸总量的消化率均为77.00％,对粗脂肪消化率分别为73.96％,64.63％,对碳水化合物消化率分别为58.46％、51.36％。在伊乐藻饲养试验中,草鱼每天最大摄食量(Y)与试验鱼体重(X)相关显著,相关系数为0.9154,关系式为Y=3.9449X~(0.8357)。在网箱中饲养草鱼,伊乐藻的粗蛋白质利用率为17.1％,饲料系数为48.2。在小型围栏中饲养草鱼,伊乐藻的粗蛋白质利用率为13.1％,饲料系数为63.4。 相似文献