鲢放养和施肥对盐碱池塘围隔生态系统浮游生物群落的影响

报道了单养链（Hypophthalmichthys molitrix)和施肥对盐碱池塘围隔生态系统浮游生物群落的影响,链的放养使浮游植物丰度,叶绿素a 含量和和初组生产力增大,浮游植物小型化,生物量以小型硅藻和绿藻占优势,裸藻和金藻占有相当比重;浮游动物生物量减少,特别是枝角类的生物量无鱼围隔大于有鱼围隔,且多是较大型的种类,施肥特别是施无机肥能显著地提高浮游植物丰度和初级生产力,浮游动物生物量也增大,施有机肥围隔浮游植物和浮游动物生物量虽高于有鱼对照围隔,但其浮游植物初级生产力,叶绿素a含量,浮游生物多样性指数,P／R系数均较低,链鱼的生长最差,文中讨论了滤食性鱼类和施肥对浮游生物的影响。     

亚热带大型水库—新丰江水库的浮游生物群落特征

于2000年丰水期和枯水期,调查了新丰江水库的浮游生物群落结构。新丰江水库处于贫营养状态,浮游生物密度和生物量均较低。浮游植物34种,丰水期以蓝、绿藻为主,分别占总数量的31.7%和26.8%,蓝藻、绿藻细胞微小,chl-a量未占优势;枯水期硅藻为优势种群,占63.9%。浮游动物22种,丰水期轮虫为主,占65.3%,枯水期桡足类占81%,丰水期动物密度较高,但丰水期以轮虫如螺形龟甲轮虫为主,枯水期以无节幼体、桡足幼体及广布中剑水蚤居多,因此枯水期生物量高于丰水期。     

罗非鱼对盐碱池塘围隔浮游生物群落的影响

本文报道了单养尼罗罗非鱼 (Orecohromisniloticus)对施肥处理下盐碱池塘围隔生态系统浮游生物群落的影响。结果表明 ,罗非鱼的放养使浮游植物丰度、叶绿素a含量和初级生产力增大 ,浮游植物小型化 ,生物量以小型硅藻和绿藻占优势 ,裸藻占有相当比重 ;浮游动物生物量也增大 ,桡足类占优势 ,枝角类小型化 ,原生动物密度增大。施肥特别是施有机肥能显著地提高浮游植物生物量 ,使透明度降低 ,但施无机肥对初级生产力和浮游动物生物量影响不大。施有机肥围隔浮游植物和浮游动物密度、浮游动物生物量和浮游生物多样性指数高于其他有鱼围隔 ,罗非鱼的生长最好。文后讨论了罗非鱼滤食和施肥对浮游生物群落结构的影响 ,并与鲢鱼的实验结果 (赵文 ,1999)进行了比较     

广东长潭水库浮游生物群落结构特征

长潭水库是广东梅州市重要的备用水源地,属于国家一类水源保护区。2010年7月,通过分析长潭水库浮游生物群落组成、生物量及多样性指数等群落结构特征和水体理化指标,揭示长潭水库富营养化水平。结果显示,长潭水库鉴定出55种浮游植物,隶属于6个门,优势种为绿藻门的栅藻（Scenedesmus sp.）、蓝藻门的微囊藻（Microcystis sp.）和伪鱼腥藻（Pseudanabaena sp.）、隐藻门的隐藻（Cryptophyta sp.）以及硅藻门的小环藻（Cyclotella sp.）和针杆藻（Synedra sp.）;藻类密度范围1.71×10⁶~2.44×10⁸ cells/L;浮游动物共检出44种,包括轮虫、枝角类和桡足类,其中轮虫是主要类群。综合营养状态指数评价结果显示,长潭水库部分水体呈轻度富营养化。典范对应分析结果显示,浮游动物、溶解氧、总氮、总磷和化学需氧量是影响长潭水库浮游植物群落结构的关键环境因子。     

两座亚热带水库真核浮游生物群落变化与构建机制

【目的】 真核浮游生物是水库生态系统的关键组分,在食物网中发挥承上启下的生态作用。本研究以两座亚热带深水水库(石兜水库和汀溪水库)为研究区,探究水库不同粒径范围(0.2–200μm、0.2–3 μm和3–200 μm)真核浮游生物群落的构建机制。【方法】 2015−2018年,对两座水库进行连续4年的季节采样,基于18S rRNA基因的V9可变区扩增测序和多元统计方法,研究水库不同粒径范围的真核浮游生物群落动态变化特征。【结果】 总体上,两座水库总真核浮游生物(0.2–200μm)与微型真核浮游生物(3–200 μm)优势门类变化的相关性较强,与微微型真核浮游生物(0.2–3μm)优势门类变化的相关性较弱。物种更替是驱动两座水库真核浮游生物群落时间动态变化的主要因素;2016年和2017年石兜水库更替物种总序列数均高于汀溪水库,而2018年则相反。与汀溪水库相比,石兜水库微微型真核浮游生物群落构建受确定性过程的影响比例更大。蓝藻叶绿素a浓度与汀溪水库真核浮游生物群落相关性较弱且不显著,而与石兜水库真核浮游生物群落显著相关,其中与石兜水库微微型真核浮游生物群落相关性最高。【结论】 微微型真核浮游生物群落比微型真核浮游生物群落更容易受蓝藻生物量影响;微型真核浮游生物群落变化一定程度上决定着总真核浮游生物群落的动态变化。全球变化背景下,应对不同粒径范围真核浮游生物进行监测,深入分析群落结构和功能变化,从而更好地保障水库生态健康和水质安全。     

对虾养殖围隔生态系浮游生物群落有机碳的代谢

浮游生物是虾池养殖生态系统生物群落的重要组分 ,在系统的物质循环和能量流动中发挥着重要作用。开展对虾养殖水体浮游生物群落有机碳代谢的研究 ,对阐明虾池养殖生态系统的结构与功能以及指导水质管理均有重要意义。本采用原位实验生态学方法 ,用中尺度实验围隔开展了研究。1　材料与方法1 1　实验围隔及管理实验围隔为 5ｍ× 5ｍ的陆基围隔。以高密度两面涂塑的聚乙烯编织布做围隔幔 ,围隔幔下部埋入池塘底泥 0 5ｍ ,并以木桩和青竹为支架架设于池塘中 (围隔内水深 1 0ｍ )。为了模拟池塘水体的自然混合状况 ,在围隔中间架设了一台 90Ｗ…     

罗非鱼对微型生态系统浮游生物群落和初级生产力的影响

本文报道罗非鱼不同放养密度对淡水微型生态系统结构与功能影响的部分研究结果。罗非鱼的捕食使微型生态系统中浮游动物密度下降,引起浮游植物密度、初级生产力和P/R系数的增长,同时使水柱透明度降低而pH值增高,以致于实验后期微型生态系统具有典型的富营养化水体的特征。就罗非鱼放养密度不同的微型生态系统而言,虽然其浮游生物密度和P/R系数存在显著的组(或部分组)间差异,但不同密度组的初级生产力水平和最终的理化状况相差不大,并且罗非鱼的收获量甚为接近。因此,实验条件下微型生态系统的群落结构和代谢的变化,按照营养级联假说不能很好地予以解释,表明微型生态系统是由捕食(下行影响)和理化因素(上行影响)共同调节或控制的。根据微型生态系统的实验结果推断,放养较大密度的罗非鱼,将会加速营养物负荷较高的天然水域富营养化的进程。     

鲢鱼的放养对水质影响的研究进展

鲢鱼的放养对水质影响的研究进展董双林（华东师范大学生物系,上海２０００６２）ＥｆｆｅｃｔｏｆＳｉｌｖｅｒＣａｒｐＳｔｏｃｋｉｎｇｏｎＷａｔｅｒＱｕａｌｉｔｙｇ：ＲｅｓｅａｒｃｈＡｄｖａｎｃｅｓ．￥ＤｏｎｇＳｈｕａｎｇｌｉｎ（ＤｅｐａｒｔｍｅｎｔｏｆＢ...     

广东沿海与粤北山区中小型水库浮游生物群落比较分析

于丰水期和枯水期对广东山区水库(赤石迳水库)、沿海水库(大水桥、赤沙水库)三个水库的湖泊区和河流区进行研究,分析水质和浮游生物群落结构。三个水库之间的浮游生物群落均有所区别,地理位置和地形不同而引起的温度差异以及外源性营养盐输入是造成浮游生物种类和数量差异的主要原因。沿海水库不分层,而山区水库丰水期温跃层明显。各水库的氮磷比均较高,chl.a水平主要受磷限制,沿海水库则多喜暖性的种类,如裸藻、隐藻、沙居剑水蚤等,山区水库发现较多喜冷性浮游生物,如金藻、透明溞等,丰水期的甲藻丰度也相对高于枯水期。     

鲤鱼种和鲢鳙对池塘浮游生物的影响

本文根据１９９０年－９月对９个鱼池的研究,报道鲤鱼种和鲢鳙对浮游生物的影响,结果表明：鲤鱼种使浮游植物和浮游动物生物量增加,浮游植物大型化,浮游动物小型化,并使浮游植物多样性增加,浮游动物多样性下降;鲢鳙密度增加,浮生物小型明显,微型藻类和超微在在浮植物中所占比重显著增加,小型浮游动物（原生动物和轮虫）在浮游动物中比重也明显增;鲢鳙密度对浮游生物多样性和浮游生物量的影响具有阶段性,当鲢鳙密度低时,     

Changes in the plankton community following introduction of filter-feeding planktivorous fish

1. We conducted enclosure experiments in a shallow eutrophic lake, in which a biomass gradient of the filter-feeding planktivore, silver carp, Hypophthalmichthys molitrix Valenciennes, was created, and subsequent community changes in both zooplankton and phytoplankton were examined.
2. During a summer experiment, a bloom of Anabaena flos-aquae developed (≈ 8000 cells mL⁻¹) solely in an enclosure without silver carp. Concurrent with, or slightly preceding the Anabaena bloom, the number of rotifer species and their abundance increased from seven to twelve species (1700–14 400 organisms L⁻¹) after the bloom in this fish-free enclosure. Protozoans and bacteria were generally insensitive to the gradient of silver carp biomass.
3. During an autumn experiment, on the other hand, large herbivorous crustaceans were more efficient than silver carp in suppressing the algae, partly because the lower water temperature (≈ 24 °C) inhibited active feeding of this warm-water fish and also formation of algal colonies. Heterotrophic nanoflagellate and bacterial densities were also influenced negatively by the crustaceans.
4. Correspondence analysis (CA) was applied to the weekly community data of zooplankton and phytoplankton. A major effect detected in the zooplankton community was the presence/absence of silver carp rather than the biomass of silver carp, whereas that in the phytoplankton community was the fish biomass before the Anabaena bloom, but shifted to the presence/absence of the fish after the bloom.     

太湖梅梁湾大型控藻围栏对浮游甲壳动物群落结构的影响

2005年对太湖梅梁湾大型鲢、鳙控藻围栏内外浮游甲壳动物群落结构的季节变化进行了监测.结果表明:围栏内外的环境因子、浮游植物生物量、浮游甲壳动物种类组成无显著差异.但鲢、鳙放养对浮游甲壳动物的生物量产生了较大的影响,围栏内浮游甲壳动物的总生物量和枝角类的生物量显著低于围栏外.总体上,枝角类各种类的生物量受鲢、鳙放养的影响程度大于桡足类的种类.太湖梅梁湾浮游甲壳动物的季节演替明显,大部分种类只是季节性出现.冬季和春季以溞(Daphnia sp.)和近邻剑水蚤(Cyclops vicnus)等大型种类为主,夏季和秋季以象鼻溞(Bosmina sp.)、角突网纹溞(Ceriodaphnia cornuta)和中华窄腹剑水蚤(Limnoithona sinensis)等小型种类为主.典范对应分析表明,透明度、温度和浮游植物的生物量是影响浮游甲壳动物季节变化的主要因素.     

不同日照时数对鲤,鲢,鳙鱼苗生长和存活的影响

不同日照时数对鲤、鲢、鳙鱼苗生长和存活的影响王吉桥,赵德树,张景全（大连水产学院养殖系,１１６０２３）（大连市碧流河水库渔场,１１６４２８）ＥｆｆｅｃｔｏｆＰｈｏｌｏｐｅｒｉｏｄｏｎｔｈｅＧｒｏｗｔｈａｎｄＳｕｒｖｉｖａｌｏｆＳｉｌｖｅｒＣａｒｐ,Ｂ...     

The effects of planktivorous fishes on the plankton community in a eutrophic lake

Stocking silver carp, a phytoplankton feeder, and bighead carp, an omnivorous plankton feeder, into an eutrophic lake at high densities caused a dramatic change in the lake ecosystem.Microcystis, which had been dominant in summer and a main food of the fishes decreased markedly, and green algae smaller than 10 μm then became dominant. Consequently, chlorophyll-a per unit area decreased slightly, while the rate of production was higher than that in the previous years. As the total density of the fishes increased (from 0.09 to 0.11 fish m⁻²), the growth of silver carp was retarded, while that of bighead carp increased.Microcystis, was unable to become dominant due to increased grazing pressure by the fishes, and small green algae became dominant. The lake conditions thus became more favourable for zooplankters which selectively consumed small green algae, and accordingly, the production of zooplankton rose. Bighead carp consumed more animal food, which they assimilate at a higher rate than plant food, and grew better in spite of the fact that the fish density increased. The feeding rate of silver carp was greatly reduced because the green algae were too small to ingest, and the fish therefore grew poorly. Results of a computer simulation of a model consisting of five compartments, representing the blue-green algae, green algae, zooplankton, silver and bighead carp, support the food-web change observed in the lake.     

Control of eutrophication by silver carp (Hypophthalmichthys molitrix) in the tropical Paranoá Reservoir (Brasília,Brazil): a mesocosm experiment

A mesocosm experiment was conducted to assess the impact of moderate silver carp (Hypophthalmichthys molitrix) biomass (41 g m^–3 or 850 kg ha^–1) on the plankton community and water quality of eutrophic Paranoá Reservoir (Brasília, Brazil). Microzooplankton (copepod nauplii and rotifers <200 m), netphytoplankton (> 20 m), total phytoplankton biomass (expressed as chlorophyll-a) and net primary productivity were significantly reduced by silver carp. Apart from increased nitrogen in the sediment, nutrients and chemical properties of the water were not affected by fish presence. The observed improvements in water quality suggest that stocking silver carp in Paranoá Reservoir to control blue-green algae is a promising biomanipulation practice.