水产养殖池塘裸藻水华的特点、危害和调控

水华是水体藻类大量生长或聚集并达到一定浓度的现象,是水体富营养化和特定条件综合作用的结果。能够形成水华的藻类有蓝藻、甲藻、硅藻、隐藻、绿藻、裸藻等，其中，蓝藻、甲藻水华比较常见，     

养殖罗非鱼水体富营养化的危害与防治

一、富营养化的危害1.引起藻类种群的变化水体富营养化极易使原来为罗非鱼提供饵料的优势种群如硅藻、甲藻等数量减少,而被一些不易消化的藻类等代替,水体颜色也随优势种群而改变。这些藻类的过度增殖,一方面,使水面形成云斑状“水华”,并发出腥臭味,恶化水质,影响罗非鱼生长发育。另一方面,藻类过多,吸附到鱼鳃上可影响呼吸,藻类死亡后,其蛋白质分解可产生羟胺、硫化氢等有毒物质,威胁着鱼类等水生生物的生存。2.造成水体溶氧的剧烈波动白天由于藻类及水生植物的光合作用,可使水体溶氧处于饱和状态,而夜晚则因大量藻类、藻类尸体、有机污染…     

蓝藻的综合开发利用

1概述近年来由于工业废水、生活废水和农业废水等大量排入淡水湖泊、水库中 ,水体富营养化 ,藻类获得了丰富的营养物质而大量繁殖。在夏秋温暖季节 ,这些湖泊、水库就会形成大片蓝绿色的藻块或藻的薄层 ,即“水华” ,漂浮在水面或分散在水中 ,呈浮动状态。“水华”的出现 ,使水体透明度下降 ,旅游观光价值减少 ;大量藻类死亡后 ,因其迅速分解 ,产生恶臭 ,消耗水中的溶解氧 ,使水生生态环境恶化。目前对于湖泊富营养化的治理主要采用三种方法 :化学方法 (杀菌剂、除草剂 )、曝气循环和物理学方法 (水位升降、土壤改良 )等。这些方法均是被动…     

盛夏养殖水体须防水华

盛夏高温季节，强碱性（pH值8～9．5）和高氮低磷的养殖水体，往往会出现蓝、绿藻大量繁殖，在水面形成一层绿色、云斑状或带状的水华。水华既阻碍空气中氧气溶入水体，藻类又与养殖水生动物争氧，加重水体缺氧程度。水华还会诱发亚硝酸盐和硫化物的毒眭，并且阻碍有毒气体逸出，使养殖水体水质恶化，造成养殖水体水生动物疾病发生。水华中的藻类死亡后，藻体蛋白腐败分解，会产生羟胺、硫化氢等有害物质，可致使养殖水生动物死亡；另外，在养殖水生动物体内积累的藻毒素，有可能通过食物链的累积效应而危害人体健康。     

富藻养殖水体中金鱼藻和篦齿眼子菜的抑藻效果研究

夏季高温时，养殖水体水华现象频繁发生，给养殖业带来巨大的损失。常见水生植物释放的活性物质在低浓度下可以起到抑藻作用，对藻类调控具有重要意义。本研究采用实验室静态模拟方法，取养殖池塘暴发蓝藻水华的水体，与沉水植物金鱼藻(Ceratophyllum demersum)及篦齿眼子菜(Potamogeton pectinatus)进行共培养，研究这2种沉水植物对养殖水华水体营养水平、藻类生长、藻类结构及浮游藻类生物多样性的影响。结果显示，金鱼藻和篦齿眼子菜可显著降低水华水体氮、磷等营养水平(P<0.05)；金鱼藻和篦齿眼子菜可有效抑制水华蓝藻(Cyanobacteria)生长，尤其对颤藻和微囊藻(Microcystis sp.)效果显著(P<0.05)，且篦齿眼子菜对水华蓝藻抑制效果更为显著。实验结束时，篦齿眼子菜培养组藻密度下降93.6%，生物量下降98.9%，叶绿素a含量下降60.5%；金鱼藻培养组藻密度下降72.5%，生物量下降86.8%，叶绿素a含量下降54.3%；金鱼藻和篦齿眼子菜的存在可促进养殖水体浮游藻类生物多样性增加，且金鱼藻提高浮游藻类生物多样性效果更显著。金鱼藻培养组浮游藻类生物多样性升高98.4%，篦齿眼子菜培养组浮游藻类生物多样性升高50.3%。本研究结果可为未来生态养殖提供理论依据和参考。     

北方池塘蓝藻的综合防治

近年来,随着城市和工业的迅速发展,大量污水排入水体,加上北方连年的干旱少雨,水源的多次重复使用,水中的藻类结构发生很大变化,由均衡的多藻种逐渐演变为以绿藻和蓝藻为主,很多水域由于蓝藻的泛滥,给养殖业带来很大的损失。1蓝藻的危害蓝藻是地球上一种最古老的植物类群,它对环境要求不严格,容易分布,大多数种类生活在淡水中,喜欢含氮量高的有机物较多的碱性水体,比较喜欢高温,大量繁殖形成水华,在水华衰老期间,大量死亡,将水中溶解氧耗尽,引起鱼类和水生动物窒息死亡,影响水生生态系统的健康发展。当水面出现蓝藻水华时,水面被厚厚的一层蓝绿色的湖靛所覆盖,水体浊度增大,透明度降低,由于蓝藻大量繁殖,极大地消耗了水体中的溶解氧,并散发出腥臭难闻的气味。蓝藻是北方池塘常见的藻类,因其分裂速度快,很容易成为池塘中的优势藻类。蓝藻表皮有一层很厚的胶质层,虽然蛋白质含量很高,但鱼类很难将其消化利用。当蓝藻过量繁殖时,如遇天气突变可引起大批死亡,蛋白质分解产生羟胺、硫化氢等有害物质,引起鱼类中毒死亡。2蓝藻的控制方法形成蓝藻繁殖过盛的池塘,多为盐碱土壤,沙浆土质,而粘土和粘壤土质的池塘,蓝藻很难成为优势种类。碱土中硅、钾、磷这几种元素是严重缺...     

生态基在大宗淡水鱼类中的应用试验

<正>生态基是一种经过处理的适合微生物生长的"床",也就是一种新型生物载体。生态基一旦放置于水中,会立即吸附水中各种水生生物到其表面,附着在生态基上的微生物非常丰富,这些微生物和藻类构成了由细菌、真菌、藻类、原生动物和后生动物等组成的复杂生态系统,对于富营养化水体起到生物过滤和生物转换的关键作用,从而改善养殖水体水质。同时生态基上由细菌、真菌、原生动物、植物、浮游动     

我国内陆水体富营养化的原因及其治理方法

随着城市和工业的不断发展，农业化肥和含磷洗涤剂大量使用，大量未经处理的生活污水和工农业废水流入湖泊和江河中，使湖泊、水库、江河中的氮、磷等营养盐不断积累，促使部分藻类以及其它水生生物异常大量繁殖，造成水体透明度下降，产生异味，水体功能遭到破坏，进而导致水体富营养化。水体严重富营养化可导致合理水生生态结构的破坏，加快湖泊等     

养殖中的肥水技巧及实例

正养殖水体水色对于养殖水生生物有很重要的影响,一个水体的肥瘦直接影响养殖的产量和养殖动物的健康。"危险"水色会导致有害藻类繁殖速度快、消耗水体营养、影响有益藻类生长;藻类容易死亡、大量消耗水体中溶氧、败坏水质;藻类死亡容易产生毒素、对养殖动物产生毒害;有害藻被摄食后不易消化、危害养殖动物的健康。经常进行肥水能有效促进光合作用,增加水体的溶     

生物碱类化合物对藻类生长抑制作用的研究进展

近年来,水体富营养化现象日趋严重,某些藻类迅速繁殖,水体溶解氧量下降,水质恶化,鱼类及其他生物大量死亡,形成水华或赤潮[1].近年来我国爆发的水华典型有"太湖蓝藻事件"、"巢湖蓝藻事件"、"滇池蓝藻事件"等.据2010年中国海洋灾害公报报道,2010年中国沿海共发生赤潮69次,累计面积10 892 km2,造成直接经济损失约2.06亿元[2].在水华、赤潮频繁发生的今天,国内外学者虽然研究出了一些有效抑藻的方法,但这些方法存在不同程度的缺陷,因此寻找高效、环保的抑藻剂显得尤为重要.     

水温升高对水体性质及水生生物的影响研究进展

全球变暖导致水温升高,河流、湖泊普遍升温,而这种增温趋势还将加剧。水温升高,直接导致水体稳定度提高,垂向对流减少,分层现象加剧,冰河解冻提前,水体封冻期缩短;间接导致水体溶解氧含量降低,尤其底层水体缺氧现象更加严重,底层水体缺氧导致沉积物中营养盐向上覆水的释放量增加,两者均会诱导水体发生气候变化富营养化。水温升高影响水生有机体的生物过程、物种组成及食物网变化;水体分层及溶解氧含量降低均会增加水体营养物负荷,促进水体浮游藻类种群发生变化;水温变化还会改变水生植物生长条件、生物量及分布,影响水体中鱼类的生存、生长发育,以及栖息地发生变化,使水生无脊椎动物种群数量减少。因此,水温增加势必对水生生态系统产生重要影响。     

基于层次分析法的北运河流域栖境得分与BMWP值相关性分析

准确描述北运河流域水生态状况，为北运河流域水生态管理决策提供支持。在北运河流域26个采样点进行采样，对河流栖境打分，采用层次分析法对河流栖境各参数得分进行加权，计算大型底栖动物BMWP值，分析北运河栖境得分与BMWP值相关性。结果表明，加权前栖境得分与BMWP值的Pearson相关系数为0.346，相伴概率为0.086，两者无显著相关性；层次分析法将河流栖境一级指标河道水量状况、河道变化状况、河滨带状况、河堤岸稳定状况分别加权为0.1466、0.1623、0.6040、0.0872，加权后栖境得分与BMWP值的Pearson相关系数为0.413，相伴概率为0.036，两者显著相关。后续研究需要进一步优化一级、二级指标的加权值，以使栖境得分值既可以有效指示不同河段的生物状况，也可以有效反映水生生物栖息地质量。     

陕西省丹江武关河省级自然保护区水生生物生态分布及其多样性

于2008年4月至2009年5月之间,对武关河自然保护区附近流域的水生生物种群进行了调查,分析该区域的自然概况和水生生物的种群、分布及多样性情况。从位置、地质地貌、气候、河流、土壤等方面,发现该处自然条件优越,为生物种群生存提供天然场所。据初步统计,该区域水生生物有浮游植物7门39属,浮游动物共15种,大型甲壳动物和软体动物6种,水生昆虫9种,鱼类35种,两栖动物4种,哺乳动物1种。并总结了全年水质变化情况和水生态系统的内部关系,为今后的进一步调查做一参考。     

河湖水生态系统服务价值核算研究及应用展望

科学有效地界定河湖水生态系统服务价值评估体系与评估指标，促进河湖水生态的可持续发展、合理制定水资源价格、为河湖水生态系统服务价值评估提供参考，同时也为河湖水资源纳入国民经济核算体系提供借鉴，为绿色经济核算提供有力的依据。从河湖水生态系统服务功能、评估体系和评估方法等方面总结了国内外研究进展，分析了现有河湖水生态系统服务体系和评估方法的优缺点。优化后的河湖水生态系统服务评估体系包括供给服务、调节服务、文化服务和支持服务4大类以及水资源供给、水质净化、科研教育和固碳能力等19项指标，优化了水资源供给、提供水产品、水质净化、防洪减灾、休闲娱乐、生物多样性保护等6个指标的评估方法。下一步要制订GEP核算技术标准，建设市场化、多元化的生态产品交易体系，将水资源开发、利用及保护情况、水资源管理生态环境效益等指标纳入审计范围，建立以水生态系统为整体、以维护河湖生态系统健康为总目标、以定量评判和可操作性为抓手的新的河湖长制考核体系。     

The role of floods and droughts on riverine ecosystems under a changing climate

Floods and droughts are key driving forces shaping aquatic ecosystems. Climate change may alter key attributes of these events and consequently health and distribution of aquatic species. Improved knowledge of biological responses to different types of floods and droughts in rivers should allow the better prediction of the ecological consequences of climate change‐induced flow alterations. This review highlights that in unmodified ecosystems, the intensity and direction of biological impacts of floods and droughts vary, but the overall consequence is an increase in biological diversity and ecosystem health. To predict the impact of climate change, metrics that allow the quantitative linking of physical disturbance attributes to the directions and intensities of biological impacts are needed. The link between habitat change and the character of biological response is provided by the frequency of occurrence of the river wave characteristic—that is the event's predictability. The severity of impacts of floods is largely related to the river wave amplitude (flood magnitude), while the impact of droughts is related to river wavelength (drought duration).     

Conservation of aquatic invertebrates: concerns,challenges and conundrums

1. Invertebrates inhabiting marine and freshwater ecosystems make important contributions to global biodiversity and provide significant services that have cascading effects across ecosystems. However, this group is grossly under‐represented in assessments of conservation status and often neglected in targeted aquatic conservation efforts.
2. In global assessments of 7857 freshwater invertebrates and 2864 marine invertebrates, 30–34% were considered Data Deficient highlighting the paucity of information for making such assessments. Of the invertebrate groups that could be assessed, those with poor dispersal abilities and high local endemism, such as many gastropods, crayfish and mussels, are the most threatened.
3. Springs and subterranean hydrological systems support the highest proportions of threatened freshwater species, while in marine environments coral reefs, lagoons and anchialine systems are particularly vulnerable.
4. Key agents of biodiversity decline in aquatic ecosystems are water pollution, overexploitation and harvesting, habitat degradation and destruction, alien invasive species, and climate change. Effects of dams and water management along with pollution from urban, agricultural and forestry sources are the main threats in freshwater ecosystems, whereas a broad range of factors have impacts on marine invertebrates, including biological resource use.
5. Significant impediments facing conservation of aquatic invertebrates are limited knowledge of their diversity, the need for broadscale actions to account for connectivity within and across ecosystems, lack of political will and investment, and the prospect that conditions may get worse before they improve, possibly not in time to save some already highly imperilled invertebrate species from extinction.

Copyright © 2016 John Wiley & Sons, Ltd.     

Linking ecology with social development for tropical aquatic conservation

1. Tropical aquatic ecosystems are species rich, with high numbers of endemics. Increasing pressure from human activities, including demands for food and energy, growing human population, and economic aspirations, highlights the need for a more concerted effort towards aquatic conservation. 2. Understanding of tropical aquatic ecosystems has developed largely from a northern temperate perspective that might not be always appropriate. Applying classic models of how water bodies function can hinder effective conservation strategies. This is coupled with very incomplete knowledge of species distributions and their ecology. 3. Better understanding of tropical aquatic ecology to guide conservation needs a research agenda that connects more strongly with the social‐ecological realities of tropical ecosystems. 4. Although approaches to conservation may be contested, a fundamental challenge to protection of aquatic habitats is a lack of capacity at the individual and institutional level. Without this, the development of improved techniques and approaches for tropical aquatic conservation will fail to reverse current trends of degradation. Research outputs on tropical aquatic ecosystems remain dominated by institutions based outside the tropics. 5. Building awareness and practice to conserve the aquatic ecosystems of the tropics can be supported through extending the dialogue across sectors and by connecting tiers of governance. An ecosystem services framework that identifies the benefits that humans derive from ecosystems provides a powerful tool, often linked with estimates of economic value. However, this can neglect important regulating services or distract from more fundamental existence value. 6. The preservation of tropical aquatic diversity will only be achieved if recognized as important at all levels, from local to global. Targeted external support can build awareness and capacity, but conserving aquatic ecosystems requires local commitment. Developing community monitoring that provides straightforward information on ecosystem health presents opportunities to connect citizens with the ecosystems that, ultimately, they depend on. Copyright © 2016 John Wiley & Sons, Ltd.     

The local responses of aquatic ecosystems to adjacent grassland conservation: Can streams of dreams exist in a degraded riverscape?

1. Landscape homogenization and the removal of riparian areas have altered stream ecosystems worldwide. Numerous conservation programmes attempt to improve water quality and increase instream habitat heterogeneity to elicit desired biological responses. However, the effectiveness of many conservation efforts on isolated stream fragments remains unknown, especially in grassland regions.
2. The effects of grassland conservation practices and the re-establishment of riparian corridors in the James River basin, South Dakota (USA) on stream water quality, habitat availability and aquatic macroinvertebrate and fish assemblages were studied in an agriculturally dominated prairie landscape.
3. Grassland conservation efforts may have repaired riparian condition, reduced turbidity and created more diverse instream habitat complexes at conservation sites based on comparisons with paired reference reaches. Reference sites were relatively homogeneous, with prevalent siltation, bank erosion and disturbances to the riparian vegetation. Owing to significant riparian vegetation development, overhanging and aquatic vegetation, benthic detritus and woody materials were significantly more common at conservation reaches.
4. Restoration efforts that assume ‘if you (re-)build it, they will come’ (i.e. the ‘field of dreams’ hypothesis) underestimate other important barriers to biodiversity restoration in dynamic, grassland riverscapes. Although aquatic organisms in grassland ecosystems are adapted to rapidly inhabit available habitats, the development of niche space at conservation reaches did not directly result in colonization by aquatic life.
5. Grassland management actions did not address stream connectivity issues or overcome land use influences elsewhere in the riverscape that may govern the responses of aquatic macroinvertebrates and fish. Stream fragmentation and continuing, damaging land use patterns seemed to exceed the positive effects of restoring isolated stream reaches in these heavily degraded catchments. Catchment-scale management strategies that combine reach-level restoration actions with efforts to improve connectivity are likely to be more successful in degraded riverscapes.

     

螺旋藻对短期增强UV-B辐射的生理生化响应

通过生物化学和对比分析的方法,研究了短期增强UV-B辐射对钝顶螺旋藻(Spirulina platensis)794光合色素、丙二醛(MDA)、类菌孢素氨基酸(MAAs)以及脯氨酸含量的影响。研究结果显示,与未经过UV-B辐射处理的藻细胞相比,增强的UV-B(240μW/cm2)辐射可导致藻细胞叶绿素a和类胡萝卜素以及藻胆蛋白含量下降,以及MDA含量显著变化(P<0.05),表明螺旋藻对UV-B辐射敏感,UV-B辐射对藻细胞光合色素具有抑制和破坏作用,对螺旋藻的膜系统也产生重要影响。而UV-B辐射可导致MAAs含量增加,脯氨酸含量随辐射时间的延长而提高,说明增强UV-B辐照能诱导藻细胞屏蔽色素合成以及抗逆物质脯氨酸的累积,这可能是螺旋藻对UV-B胁迫所做出的适应性反应。     

Effects of fish species richness and assemblage composition on stream ecosystem function

Abstract –  Biodiversity is declining across aquatic ecosystems because of biological invasions and species extinctions. Because fishes have pervasive effects on ecosystems through species-specific food web interactions, alterations to species and functional richness, and composition of natural assemblages could have negative effects on aquatic ecosystem function. In this study, I tested the effects of fish species and functional richness, and assemblage composition on primary production (PPR), benthic invertebrate density, and benthic particulate organic matter (BPOM) in a 42-day experiment in artificial stream mesocosms. I found that fish species richness and assemblage composition were important predictors of PPR in stream mesocosms. However, the effect of species richness on PPR increased with time, suggesting that richness-related effects might strengthen as the magnitude of community-level interactions increases in ecosystems. There was no effect of fish species or functional richness or assemblage composition on benthic invertebrate densities or BPOM. These data provide additional support that fishes can be important regulators of ecosystem function in aquatic systems, and suggest that positive effects of fishes on ecosystems can be strengthened by increased species richness and composition of the assemblage. This study broadens the applicability of the biodiversity ecosystem-function literature to a new suite of taxa, supporting the overall hypothesis that ecosystem functions and services are likely to decline in response to species extinctions.