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1.
Christopher R. Mueller Arnold G. Eversole Hakan Turker David E. Brune 《Journal of the World Aquaculture Society》2004,35(3):372-382
Growers produce over 2.8 million kg of catfish (over $350 million wholesale revenue) annually in the United States. The microbiology of the phytoplankton community in culture water affects the growth and flavor of the catfish and is a consideration for growers. Filter feeders, like silver carp and freshwater mussels, in controlled growth systems are used to adjust the phytoplankton species. Our goal was to successfully control the algal populations with filter feeders in catfish production. We used silver carp Hypophthalmichthys molitrix as a filter feeder in Partitioned Aquaculture System (PAS) water. Silver carp completely eliminated the cyanobacteria Microcystis by size and biovolume reduction. This created the desired effect of small green algae dominating the algal community. A significant but opposite change was observed when freshwater mussels Elliptio complanata filtered PAS water resulting in Microcystis biovolume and size dominance in the PAS; a less desirable algal community. This study also showed an immediate shift in the phytoplankton community when silver carp and mussels were interchanged between PAS waters. The size-selective filtration by the two filter-feeding taxa was important in determining the composition of the PAS phytoplankton community, and it was apparent that filtration with silver carp successfully depleted undesirable algae. 相似文献
2.
基于2011~2016年春季对赤水河4个断面浮游植物的调查,分析浮游植物群落结构变化及优势种生态位,揭示赤水河春季浮游植物群落变化规律、优势种的生态位分化及其环境适应性,为赤水河浮游植物群落结构特征研究提供基础资料。调查结果表明,6年间在赤水河共采集到浮游植物7门68属233种（变种）,主要为硅藻,占比超过60.51%;浮游植物细胞密度在（17.28~136.68）×10^4cells/L之间波动,各段面浮游植物密度年际间变化无显著差异,浮游植物群落组成时间异质性较空间异质性明显,时空方差分解显示时间变异可解释总变异的24.5%,空间变异仅解释总变异的2%;浮游植物多样性指数显示2014年与2016年赤水河处于轻或无污染状态,2011~2013年与2015年受到中度人为影响。2011~2016年春季赤水河共出现优势种31种（变种）,主要为广生态位和中生态位种,生态位重叠指数在同一门类物种中最高,在不同门类物种中最小。分析结果表明赤水河春季浮游植物对水生态环境的适应能力强,对水环境的变化有较好适应性。 相似文献
3.
为了探究色林错-普若岗日国家公园潜在建设区夏季浮游植物群落及优势种生态特征,于2015年和2016年8月对浮游植物群落进行了调查分析,并运用生态位宽度、生态位重叠及生态响应速率等方法测定优势种的生态位量度。结果表明：（1）色林错-普若岗日国家公园潜在建设区共鉴定出浮游植物127种,隶属于3门5纲11目18科35属,其中优势种5种,隶属2门5属,优势种丰度和优势度在不同区域均有差异;（2）泉生菱形藻（Nitzschia fonticola）生态位宽度最大,嗜盐舟形藻（Navicula halophila）生态位宽度最小;（3）浮游植物优势种生态位重叠程度不高,种间竞争弱,群落结构较为稳定;（4）浮游植物优势种呈发展或衰退趋势是不同浮游植物优势种间竞争的必然结果。本研究结果为色-普国家公园潜在建设区浮游植物多样性积累基础数据,为探讨生态位分化理论下的种间关系、资源利用及生态适应机制提供参考。 相似文献
4.
为探讨pH和氮磷比对青岛大扁藻(Tetraselmis helgolandica)和微小原甲藻(Prorocentrum minimum)生长竞争的影响,本研究首先根据对虾养殖水体pH值的范围设置了7.5,8.0,8.5和9.0共4个pH梯度,获得了青岛大扁藻抑制微小原甲藻的最佳pH;在该pH条件下,设置了氮磷比分别为3:2(高富磷组),6:1(富磷组),24:1(对照组)和96:1(富氮组)等4个梯度,其中,单种培养体系中只接种青岛大扁藻或者微小原甲藻,混合培养体系中同时按照1:1的比例接种青岛大扁藻和微小原甲藻。结果表明,混合培养体系中,青岛大扁藻在pH 8.5和pH 9.0时,出现拐点时间最晚,均为7 d;而微小原甲藻在pH 8.5和pH 9.0时,出现拐点时间最早,均为3 d。pH 8.5时青岛大扁藻对微小原甲藻的竞争抑制参数最大,青岛大扁藻抑制微小原甲藻的最佳pH为8.5。单种培养体系中,微小原甲藻拐点出现的时间在高富磷组、对照组和富氮组中均晚于青岛大扁藻;混合培养体系中,对照组中微小原甲藻和青岛大扁藻拐点出现时间分别为4 d和3 d,而其他处理组2种微藻拐点出现的时间分别相同。氮磷比影响混合培养中2种微藻的竞争抑制参数,其中,96:1(富氮组)中拐点之后青岛大扁藻对微小原甲藻的竞争抑制参数(α)的平均值为9.2063,微小原甲藻对青岛大扁藻的竞争抑制参数(β)为3.4886。以上研究表明,对虾养殖水体中,青岛大扁藻抑制微小原甲藻的最佳条件是:pH为8.5,氮磷比为96:1。 相似文献
5.
为研究河流型水库浮游植物群落结构与水环境因子的关系，对湖北恩施大龙潭水库水环境因子和浮游植物进行调查,利用Pearson相关性分析法对调查结果进行分析。水库在调查期间共鉴定到186种藻类，隶属于7门89属，其中硅藻门（79种）>绿藻门（55种）>蓝藻门（29种）>甲藻门（9种）>隐藻门（7种）>裸藻门（6种）>金藻门（1种）。Margalef丰富度指数平均值在0.94～1.30，依据丰富度指数水质评判标准判断水质整体为中污染。水库浮游植物总细胞密度在夏季较高，在冬季显著下降。水库从夏季至秋冬季节浮游植物总细胞密度在3.889×105～282.983×105cell/L的区间内变化，其均值为79.864×105cell/L。Pearson相关性分析表明，浮游植物总密度与温度、溶解氧、pH、总磷、高锰酸盐指数呈极显著正相关；与电导率、硝酸盐氮呈极显著负相关。冗余分析表明，温度、pH和高锰酸盐指数是影响水库浮游植物群落结构最主要的环境因子。大龙潭水库较高的海拔和较大的流域面积，有利于硅藻生长；水库年平均水深较深，蓝藻通过水流运动停留在水库上层成为优势种群。 相似文献
6.
To determine effects of aquacultured oysters Crassostrea virginica (Gmelin, 1791) on the overlying water column, a mesocosm study was performed at the Marine Ecosystem Research Laboratory (MERL) from June to October, 2000. The MERL facility is located adjacent to Narragansett Bay and consists of fourteen 13,000-l mesocosm tanks designed to simulate the Bay environmental conditions. Two hundred oysters (≈35 mm valve height; nominally filtering about 55 l/day/individual) were placed into three mesocosms, and three mesocosms were maintained without oysters as controls. Experiments were run with varying rates of water exchange in the tanks ranging from 0% to 100% per day (13,000 l/day). Parameters that were measured and compared between the two treatments included chlorophyll-a, particulate organic and inorganic matter, sedimentation, nitrate, ammonia, selected phytoplankton species and oyster growth rates. Oysters affected phytoplankton species composition and increased rates of sedimentation. Large diatoms were net sampled, and Nitzchia striata was predominant in mesocosms with oysters, while Skeletonema costatum dominated the control tanks. Ammonia excretion rates were determined for C. virginica using the salicylate–hypochlorite method. Ammonia excretion can be described by the allometric equation E=50.65w0.699 when E is the ammonia excretion rate in μg/h, and w is the soft tissue dry weight in grams. Based on rates of ammonia excretion by oysters and observed steady states of ammonia and other forms of inorganic nitrogen in mesocosm tanks, it can be hypothesized that ammonia generated by oysters is taken up by rapidly regenerating phytoplankton in the water column. 相似文献
7.
Sbastien Lefebvre Ian Probert Christel Lefranois Jrme Hussenot 《Aquaculture (Amsterdam, Netherlands)》2004,240(1-4):211-231
Natural phytoplankton populations were cultured in outdoor continuous cultures using fish-farm effluents as the source of nutrients. The dilution rate was assumed to be the integrating factor of phytoplankton growth and biomass development (flux and stock). In this context, the combined effects of (i) dilution rates of the outdoor culture and (ii) ambient conditions were tested on phytoplankton growth, biomass and cycling of the major nutrient elements (C, N and P). Experiments were carried out in outdoor polyester tanks (0.7 m deep), homogenised by gentle aeration. Si/P ratio was balanced at around 5 in the inflow in order to induce diatom domination while maintaining high N and P assimilation by phytoplankton. Nutrient cycling was assessed through analyses of the different forms of particulate and dissolved nutrients in the inflow and the outflow. Culture dilution rates determined the longevity of the culture and the assimilation efficiency of nutrients. Dissolved phosphorus was the most limiting nutrient. The optimal dilution rate was approximately 0.5 day−1 at 10 °C and 1.5 day−1 at 20 °C with a mean diatom biomass of 9 μM P. Under these conditions, 80% of the dissolved nutrients provided to the tanks were transformed, a production of 8 g C m−2 day−1 and an assimilation rate of 0.3 g P m−2 day−1 were recorded. Assimilation by diatoms was the major pathway of nutrient cycling. During the experiment, a bottom sediment developed progressively and this also played an important role in denitrifying the excess dissolved nitrogen in the fish-farm effluent. However, the results showed that diatom biomass can collapse and we hypothesize that this was the consequence of an increase in cellular sinking rates due to cell aggregation under nutrient or light stress. Modelling approaches are needed in future research in order to determine optimal dilution rates taking into account phytoplankton growth rates, nutrient inputs and ambient conditions (e.g. light and temperature). 相似文献
8.
Shannon L. Meseck 《Aquaculture (Amsterdam, Netherlands)》2007,273(4):566-572
In aquaculture, large volumes of phytoplankton are often grown outdoors to reduce costs. However, growing microalgae in an environment not as well-controlled as in the laboratory can lead to unwanted phytoplankton, including cyanobacteria, contaminating a culture. A cyanobacterial contaminant was isolated from an outdoor culture of Tetraselmis chui (PLY429) at the Milford Laboratory. This study investigated the growth of PLY429 and the cyanobacterium in pure cultures and a mixed culture in a pH range of 6.5-9.5. The division of PLY429 was greater at a pH range of 7.0-8.0; whereas, for the cyanobacterium, higher growth was obtained at pH 8.0-9.0. Results from combined cultures of PLY429 and the cyanobacterium grown at various pHs indicated that maintaining pH near 7.1 yields higher growth of PLY429 than those of the cyanobacterium. These findings suggest that controlling pH may reduce the population of a cyanobacterial contaminant in an aquaculture feed culture. 相似文献
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10.
营养盐和光照对浮游植物群落结构的影响 总被引：3，自引：0，他引：3
2006年4月在沙埕港湾口处网箱养殖区,研究营养盐和光照对浮游植物类群及其优势种生长的影响。结果表明,微、小型浮游植物在100%自然光强下生长最快,微微型浮游植物在50%自然光强下生长最快。在各形态无机氮（N）、磷（P）营养盐存在的情况下,浮游植物会首先利用氨氮（NH4-N）,但培养后期NH4-N加富组的浮游植物丰度低于亚硝酸盐（NO2-N）加富组和硝酸盐（NO3-N）加富组。营养盐加富在短期内引起浮游植物数量的快速增加,当营养盐浓度达到一定水平后对浮游植物的生长不利,其抑制作用随浮游植物种类而异;随着营养盐消耗,浮游植物的数量和多样性均下降。微、小型浮游植物丰度与NO3-N、N/P呈显著相关,相关系数分别为-0.625、0.521;微微型浮游植物丰度与磷酸盐（PO4-P）呈显著相关,相关系数为0.530。 相似文献
11.
长沙梅溪湖为新兴城市人工湖泊,是国家级新区湘江新区的城市“海绵体”,其水环境与水生态状况是该区域高质量发展关注的重点,对维护湘江新区生态环境具有重要意义。为揭示梅溪湖水生态现状,分季度采集梅溪湖水样,分析浮游植物群落特征及其与环境因子的关系。结果显示梅溪湖浮游植物共有7门96种,其中以绿藻、硅藻和蓝藻种类数居多,占总种类数的86.46%,主要优势种为细小隐球藻（Aphanocapsa elacjista）、小环藻（Cyclotella sp.）、链状曲壳藻（Achnanthes catenata）和尖尾蓝隐藻（Chroomonas acuta）,优势种具有明显季节交替性。浮游植物年均密度为（23.97±9.95）×10^6 cells/L,各季度东部水域密度均高于西部水域;多样性指数评价结果表明梅溪湖水体处于中度污染和中-富营养状态,与水质评价结果基本一致。浮游植物与环境因子基于转化的冗余分析结果显示,水温、氧化还原电位、总氮和亚硝酸盐氮是影响梅溪湖浮游植物群落的主要驱动因子,控制总氮等营养盐的输入将是改善梅溪湖水质和营养状态的有效手段。 相似文献
12.
The growth rate of the bay scallop Argopecten irradians was studied in relation to temperature and phytoplankton concentration. Results suggest that normal variations in phytoplankton concentration do not influence the growth rate of scallops in their natural habitat. Increasing the concentration of phytoplankton above natural levels did not result in increased growth rates while decreasing the phytoplankton concentration resulted in a decrease in growth rate of the scallops. Under extremely low phytoplankton concentrations, such as those that characterize ‘clean water’ effluent from a culture system, the animals ceased growing. A mathematical model of scallop growth rate as a function of phytoplankton concentration is proposed as a tool for comparing the functioning of different suspension feeders in aquaculture systems. 相似文献
13.
澜沧江囊谦段夏秋季浮游植物群落结构初步研究 总被引：5，自引：1，他引：5
2011年夏季(6月)和秋季(9月)对澜沧江囊谦段的浮游植物进行初步研究。结果表明,澜沧江囊谦段浮游植物共计4门、57种(属);其中,硅藻门种类最多,为33种(属),占总种类数的57.9%;其次是绿藻门,为13种(属),占22.8%,蓝藻门10种(属),占17.5%,甲藻门仅检到1种,占1.8%。夏秋两季澜沧江囊谦段均以喜低温的硅藻为主,绿藻、蓝藻种类秋季多于夏季,甲藻仅在夏季出现。浮游植物优势种以硅藻为主,占75.0%,种类有尖针杆藻(Synedra acus)、普通等片藻(Diatoma vulgare)、舟形藻(Navicula sp.)、桥弯藻(Cymbella sp.)、曲壳藻(Achnanthes sp.)、异极藻(Gomphonem sp.)、颤藻(Oscillatoria sp.)和席藻(Phormidium sp.)。浮游植物数量为13.26×104～375.59×104个/L,平均数量99.36×104个/L;生物量为0.0445～1.9972mg/L,平均0.4915mg/L。浮游植物数量和生物量均以硅藻最高,分别占总数量的61.2%和总生物量的71.3%。分析显示,各采样点浮游植物多样性指数、均匀度指数较高,均值分别为2.24、0.48;表明该河段浮游植物群落比较稳定,种类分布较为均匀,体现了贫营养型河流的特征,水域环境良好。 相似文献
14.
Parallelism in thermal growth response in otoliths and scales of brown trout (Salmo trutta L.) from alpine lakes independent of genetic background 
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下载免费PDF全文 Low density in natural populations of salmonids has predominantly been managed by stocking of non‐native conspecifics. Due partly to domestication, introduced non‐native fish may be maladapted under natural conditions. Interbreeding between introduced and wild individuals may therefore impair local adaptation and potentially population viability. Brown trout (Salmo trutta L.) from three headwaters (with stocked fish) and three interconnected lakes (with native fish) on the Hardangervidda mountain plateau, southern Norway, were tested for differences in thermal effects on scale and otolith growth. Otolith and scale annuli widths from immature brown trout showed positive correlation with mean annual summer temperature for all six sampled populations. In mature individuals, a similar positive thermal correlation was evident for the otoliths only. Interannuli width measurements from scales indicate a halt in somatic growth for brown trout in this alpine environment when reaching ages between 7 and 9 winters, coinciding with age at maturity. Our study indicates that otolith growth follows summer temperature even when individuals do not respond with somatic growth in these populations and that introduced brown trout and introgressed populations have similar thermal growth responses. Due to the continued otolith growth after stagnation in somatic growth and the impact of fluctuations in summer temperature, the utilisation of otolith annuli widths for back calculation of length at age should be treated with caution. 相似文献
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在京杭运河苏北段秋冬两季开展水环境监测和浮游植物调查,为京杭运河苏北段的水生态环境保护提供参考。2020 年 10 月（秋季）和 2021 年 1 月（冬季）,对京杭运河苏北段布设的 16 个采样点开展了系统的水环境和浮游植物调查,根据Shannon-Wiener 多样性指数、 Pielou 均匀度指数和浮游植物细胞丰度进行了水质及水体营养状态的评价,利用 Pearson 相关性分析明确了浮游植物与环境因子的关系。结果显示：京杭运河苏北段秋冬季共采集到浮游植物 8 门 101 种,其中秋季 7 门 52 种、冬季 5 门 63 种,秋冬季均是以绿藻门和硅藻门为主,2个门类的种类数在秋冬季浮游植物种类总数的占比分别达到了 73% 和 82%;秋季浮游植物细胞丰度均值为 49.1×104 个/L,生物量均值为 0.344 mg/L,冬季浮游植物细胞丰度均值为 15.0×104 个/L,生物量均值为 0.193 mg/L;秋冬季浮游植物优势种主要以硅藻门（Bacillariophyta）和绿藻门（Chlorophyta）为主;秋季浮游植物的多样性评价结果优于冬季,秋冬季水体营养状态均为中营养型,相关性分析表明氮对京杭运河苏北段浮游植物群落结构的影响大于磷;另外,行船引起的水体扰动也是造成浮游植物群落差异的重要因素。 相似文献
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为了解贵州白云岩喀斯特世界自然遗产地浮游植物群落结构及其与环境因子的关系,于2017年秋季(10月)、2018年冬季（1月）、2018年春季（4月）、2018年夏季（8月）对遗产地境内黄洲河流域的浮游植物群落种类组成、优势种、丰度以及多样性的时空变化进行研究,并应用Pearson相关性分析和冗余分析（RDA）探究环境因子总氮（TN）、氨氮（NH3-N）、总磷（TP）、叶绿素a（Chl-a）、溶解氧（DO）、高锰酸盐指数（CODMn）、水温（WT）对黄洲河浮游植物群落结构的影响。结果表明,调查共鉴定出藻类6门、29科、37属、38种,以硅藻门和绿藻门居多。按季节划分,黄洲河流域优势种共9种,其中硅藻门5种,?绿藻门1种,?蓝藻门3?种;按空间划分,黄洲河流域优势种共19种,其中硅藻门9种,绿藻门4种,蓝藻门6种。浮游植物年均丰度为36.45×104个/L,夏季的丰度最高,达到89.7×104个/L,春秋季次之,冬季最低,仅8.9×104个/L。全年Margalef丰富度指数（D）、Shannon多样性指数（H）及Pielou均匀度指数（J）分别为0.34 ~0.51、1.18~1.4及0.72~0.84。Pearson相关性分析和冗余分析(RDA) 表明,影响遗产地浮游植物丰度和分布的主要环境因子为WT、CODMn、Chl-a。 相似文献
17.
M. C. Belk J. B. Johnson K. W. Wilson M. E. Smith D. D. Houston 《Ecology of Freshwater Fish》2005,14(2):177-184
Abstract – Leatherside chub ( Snyderichthyes copei Jordan & Gilbert) comprises two lineages (northern and southern) whose centres of geographical range differ by about 3° latitude corresponding to about 30% shorter growing season and about 2 °C lower mean temperature during the growing season. We document patterns of variation in size-at-age among populations of leatherside chub in nature, and we test for variation in intrinsic growth rate of juvenile chub in a common-environment experiment to determine if lineages exhibit different intrinsic growth rates. Northern leatherside chubs at ages 1–3 were about 15% shorter in length compared with southern populations. Variation in hatching date or age at maturity could not account for differences in growth and body size, suggesting that temperature-specific intrinsic growth rates differed among populations. Based on a common environment experiment, we found that reaction norms for temperature-specific growth in length and mass were crossed. At the lower temperature, individuals from the north exhibited higher intrinsic growth in length, and at the higher temperature individuals from the south exhibited higher intrinsic growth in mass. Crossing reaction norms for temperature-specific intrinsic growth rates support a model of local adaptation to thermal regime. 相似文献
18.
包头南海湖非冰封期浮游植物的时空动态特征 总被引：1，自引：0，他引：1
为了解包头南海湖浮游植物群落非冰封期的时空动态特征,2017年5-10月,在南海湖设置了12个监测站位,监测浮游植物时空变化,并同步监测水环境因子。结果表明,南海湖12个站位共鉴定出浮游植物146种(含变种);其中,绿藻门(Chlorophyta)59种,蓝藻门(Cyanophyta)31种,硅藻门(Bacillariophyta)37种,裸藻门(Euglenophyta)9种,金藻门(Chrysophyta)5种,黄藻门(Xanthophyta)3种,隐藻门(Cryptophyta)2种。浮游植物密度为23.35×10~6～115.59×10~6个/L;优势度分析表明,5-6月主要以绿藻占优势,优势种为四尾栅藻(Scenedesmus quadricauda)和螺旋弓形藻(Schroederia spiralis);7-9月主要以蓝藻占优势,优势种为微小平裂藻(Merismopedia tenuissima)和水花束丝藻(Aphanizomenon flosaquae);10月以绿藻和硅藻占优势,优势种为四尾栅藻和近缘针杆藻(Synedra affinis)。空间上呈现出沿进水口向湖心区逐渐递增的趋势,湖心区整体密度较高,而排污口和芦苇区处密度相对较低;冗余分析(RDA)表明,氨氮、化学需氧量、pH、叶绿素-a以及水温是影响浮游植物分布的主要水环境因子,绿藻与总氮关系密切,蓝藻主要受总磷的影响,硅藻受pH影响较大。 相似文献
19.
2009年的枯水期（5月）和丰水期（7月）,在桃山水库对浮游植物结构群落和水质状况进行了调查研究,结合生物监测和理化监测手段,基于浮游植物优势度、丰度、优势度以及综合指数评价方法,对研究水库进行了生态评价。结果显示：（1）桃山水库浮游植物共有7门46属73种及变种,其中以绿藻为主,分别占44 %;（2）生物量在2.29-10.96 mg﹒L-1之间,丰度变幅在(38.76-124.44)×105 ind.﹒L-1之间;（3）枯水期优势种以硅藻为主,丰水期优势种以以蓝藻、绿藻为主;（4）综合营养指数为42.0-60.1。综合评价结果表明：桃山水库枯水期和丰水期水质营养状态为轻富营养化,化学需氧量是影响桃山水库浮游植物群落结构的主要环境因子。 相似文献
20.
神农溪作为“引江补汉”工程的比选调水源头之一，维持其良好水质状况具有重要意义。而作为反映水环境质量重要指标的浮游植物群落结构特征，则又受到三峡季节性蓄水倒灌的影响，辨识神农溪浮游植物群落结构的时空变动特征及其与环境因子的关系，有利于对浮游植物采取有针对性的防治措施。本研究于2016年5月（低水位运行期）和10月（高水位运行期）沿神农溪上游至下游江段开展了调查，采用数量生态学方法研究了神农溪浮游植物群落结构的时空变动特征及其与环境因子的关系，结果显示：浮游植物种类数5月比10月略低，但均以绿藻门、硅藻门和蓝藻门种类为主；浮游植物密度5月在各个采样站点间呈波动分布特征，而10月从河口区到上游回水变动区呈纵向梯度分布特征；两次采样的优势种均以富营养型水体指示藻类为主；两次采样的群落结构空间分布特征存在较大差异，但均不显示明显的沿河流纵向梯度分布特征；影响浮游植物空间分布的最重要环境因子5月为高锰酸盐指数，而10月则为浊度；浮游植物主要种类的空间差异性与所处采样点环境因子的浓度梯度差异以及藻类自身生物学特征明显相关。该研究结果可为神农溪水环境保护提供基础资料。 相似文献