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1.
Pettine M Casentini B Fazi S Giovanardi F Pagnotta R 《Marine pollution bulletin》2007,54(9):1413-1426
The trophic status classification of coastal waters at the European scale requires the availability of harmonised indicators and procedures. The composite trophic status index (TRIX) provides useful metrics for the assessment of the trophic status of coastal waters. It was originally developed for Italian coastal waters and then applied in many European seas (Adriatic, Tyrrhenian, Baltic, Black and Northern seas). The TRIX index does not fulfil the classification procedure suggested by the WFD for two reasons: (a) it is based on an absolute trophic scale without any normalization to type-specific reference conditions; (b) it makes an ex ante aggregation of biological (Chl-a) and physico-chemical (oxygen, nutrients) quality elements, instead of an ex post integration of separate evaluations of biological and subsequent chemical quality elements. A revisitation of the TRIX index in the light of the European Water Framework Directive (WFD, 2000/60/EC) and new TRIX derived tools are presented in this paper. A number of Italian coastal sites were grouped into different types based on a thorough analysis of their hydro-morphological conditions, and type-specific reference sites were selected. Unscaled TRIX values (UNTRIX) for reference and impacted sites have been calculated and two alternative UNTRIX-based classification procedures are discussed. The proposed procedures, to be validated on a broader scale, provide users with simple tools that give an integrated view of nutrient enrichment and its effects on algal biomass (Chl-a) and on oxygen levels. This trophic evaluation along with phytoplankton indicator species and algal blooms contribute to the comprehensive assessment of phytoplankton, one of the biological quality elements in coastal waters. 相似文献
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生物操纵与非经典生物操纵的应用分析及对策探讨 总被引：8，自引：2，他引：6
分析了生物操纵(biomanipulation)和非经典生物操纵(non-traditional biomanipulation)理论的原理、应用条件及局限性,提出了在局部水体治理湖泊富营养化的对策.分析认为:生物操纵的核心内容是利用浮游动物控制藻类;但浮游动物不能有效控制丝状藻类和形成群体的蓝藻水华;我国的大型浅水湖泊浮游动物数量一般并不多,对浮游植物摄食压力不大;在浅水湖泊,浮游动物摄食藻类后很快分解、释放又进入物质循环,因此不能治理湖泊富营养化;浮游动物是浮游植物和鱼类等经济水生动物之间重要的营养通道,过分追求保护浮游动物是值得思考和研究的问题.而非经典生物操纵的核心内容是利用鱼类直接控制蓝藻水华;当鲢、鳙鱼达到阈值密度可以控制蓝藻水华,但很难控制所有藻类和降低N、P治理湖泊富营养化.在局部水体治理湖泊富营养化的对策是:把鱼类控藻、水生植被恢复和局部水域生态系统重建相结合,形成具有利用与控制蓝藻生产鱼类、吸收氮磷净化水质功能的"水质生物调控单元". 相似文献
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Type-specific and indicator taxa of phytoplankton as a quality criterion for assessing the ecological status of Finnish boreal lakes 总被引：6，自引：0，他引：6
Key issues in the implementation of the Water Framework Directive are classification of lakes using biological quality parameters and type-specific reference conditions. This work is one of three studies considering different metrics of phytoplankton in the classification of ecological status. Phytoplankton was studied in a total of 55 Finnish boreal lakes, including 32 reference lakes. We tested the suitability of taxonomic composition and abundance of phytoplankton groups for biological classification. We also preliminarily determined the type-specific taxa for the studied lakes. The type-specific taxa for reference conditions are coincidently the indicator species/taxa for high ecological status. Interestingly, some taxa type-specific for impacted oligo-humic lakes proved to be the type-specific taxa for humic reference lakes. The pressure of human impact was observed not only as increase of biomass but also as changes in the species composition. The phytoplankton composition indicated the ecological status of impacted lakes moderately well. There was some variation in the indications given by different algal groups, probably due to the preliminary class boundaries used. However, the preliminary combination of indicative parameters to estimate the ecological status of the studied impacted lakes was in general in accordance with earlier classification of water quality in Finnish lakes. 相似文献
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随着全球气候变化和水体富营养化,在过去几十年中蓝藻水华改变了全球的淡水生态系统.蓝藻因独有的藻蓝蛋白而大多呈现蓝绿色,因此其水华也常称为蓝绿藻水华.然而随着蓝藻水华关注度的不断提升,尤其是监测和研究的不断深入,经常在水体中发现蓝藻水华出现黄化的现象.例如,太湖出现的黄色蓝藻水华,冬春季以长孢藻属(Dolichospermum)水华为主,夏秋季以微囊藻属(Microcystis)水华为主.即使外观看起来是蓝绿色的蓝藻水华,但仔细观察形成蓝藻水华的群体颗粒,也有部分呈现黄色,反之亦然.实际上,鉴于色素组成的差异性,也许水体中就没有两个颜色完全一致的蓝藻群体颗粒.目前对于黄色的蓝藻水华及其形成机理,国内外鲜有报道和研究.光照和氮限制被认为是最有可能的原因.在关注蓝藻水华黄化的同时,更应该关注和研究这些颜色变化给蓝藻水华及水环境所带来的风险和挑战,尤其是对水生态管理工作的启发和意义. 相似文献
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随着湖泊流域经济的快速发展,蓝藻水华频繁暴发的现象越来越严重,水体富营养化已经成为国内外重大环境问题.浮游植物是水体的初级生产者,是衡量水体富营养化程度的主要指标之一,遥感技术则是探测水体浮游植物时空分布的重要手段.在收集整理近千篇国内外水体浮游植物遥感研究论文的基础上,从卫星数据源、研究内容及研究方法等角度,总结了遥感技术在富营养化湖泊浮游植物监测应用的历史进展、研究重点及发展趋势.研究表明,现有的富营养化水体浮游植物遥感研究,以湖泊蓝藻水华问题为切入点,研究视角由水体表层(藻华面积、色素浓度)转至水下三维(藻总量),研究方法从定性识别转向定量反演,研究内容从监测蓝藻水华推进到探测不同类群蓝藻,逐渐形成了以应用为导向,"MODIS/VIIRS大中型湖泊日常监测—GF/Sentinel2小型湖泊针对性监测—无人机应急监测"的浮游植物遥感综合监测体系.上述研究梳理了富营养化水体浮游植物遥感监测湖泊水环境学科的发展动向,以期为从事蓝藻水华生态灾害监测和预警人员提供重要的技术支撑和理论参考. 相似文献
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Biological mechanisms driving the seasonal changes in the internal loading of phosphorus in shallow lakes 总被引：1，自引：6，他引：1
XIE Ping 《中国科学D辑(英文版)》2006,49(Z1)
Because of the obvious importance of P as a nutrient that often accelerates growth of phytoplankton (including toxic cyanobacteria) and therefore worsens water quality, much interest has been devoted to P exchange across the sediment-water interface. Generally, the release mode of P from the sediment differed greatly between shallow and deep lakes, and much of the effort has been focused on iron and oxygen, and also on the relevant environmental factors, for example, turbulence and decomposition, but a large part of the P variation in shallow lakes remains unexplained. This paper reviews experimental and field studies on the mechanisms of P release from the sediment in the shallow temperate (in Europe) and subtropical (in the middle and lower reaches of the Yangtze River in China) lakes, and it is suggested that pH rather than DO might be more important in driving the seasonal dynamics of internal P loading in these shallow lakes, i.e., intense photosynthesis of phytoplankton increases pH of the lake water and thus may increase pH of the surface sediment, leading to enhanced release of P (especially iron-bound P) from the sediment. Based on the selective pump of P (but not N) from the sediment by algal blooms, it is concluded that photosynthesis which is closely related to eutrophication level is the driving force for the seasonal variation of internal P loading in shallow lakes. This is a new finding. Additionally, the selective pump of P from the sediment by algal blooms not only explains satisfactorily why both TP and PO4-P in the hypereutrophic Lake Donghu declined significantly since the mid-1980s when heavy cyanobacterial blooms were eliminated by the nontraditional biomanipulation (massive stocking of the filter-feeding silver and bighead carps), but also explains why TP in European lakes decreased remarkably in the spring clear-water phase with less phytoplankton during the seasonal succession of aquatic communities or when phytoplankton biomass was decreased by traditional biomanipulation. Compared with deep lakes, wax and wane of phytoplankton due to alternations in the ecosystem structure is also able to exert significant influences on the P exchange at the sediment-water interface in shallow lakes. In other words, biological activities are also able to drive P release from sediments, and such a static P release process is especially more prominent in eutrophic shallow lakes with dense phytoplankton. 相似文献
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Xie Ping 《中国科学D辑(英文版)》2006,49(1):14-27
Because of the obvious importance of P as a nutrient that often accelerates growth of phytoplankton (including toxic cyanobacteria) and therefore worsens water quality, much interest has been devoted to P exchange across the sediment-water interface. Generally, the release mode of P from the sediment differed greatly between shallow and deep lakes, and much of the effort has been focused on iron and oxygen, and also on the relevant environmental factors, for example, turbulence and decomposition, but a large part of the P variation in shallow lakes remains unexplained. This paper reviews experimental and field studies on the mechanisms of P release from the sediment in the shallow temperate (in Europe) and subtropical (in the middle and lower reaches of the Yangtze River in China) lakes, and it is suggested that pH rather than DO might be more important in driving the seasonal dynamics of internal P loading in these shallow lakes, i.e., intense photosynthesis of phytoplankton increases pH of the lake water and thus may increase pH of the surface sediment, leading to enhanced release of P (especially iron-bound P) from the sediment. Based on the selective pump of P (but not N) from the sediment by algal blooms, it is concluded that photosynthesis which is closely related to eutrophication level is the driving force for the seasonal variation of internal P loading in shallow lakes. This is a new finding. Additionally, the selective pump of P from the sediment by algal blooms not only explains satisfactorily why both TP and PO4-P in the hypereutrophic Lake Donghu declined significantly since the mid-1980s when heavy cyanobacterial blooms were eliminated by the nontraditional biomanipulation (massive stocking of the filter-feeding silver and bighead carps), but also explains why TP in European lakes decreased remarkably in the spring clear-water phase with less phytoplankton during the seasonal succession of aquatic communities or when phytoplankton biomass was decreased by traditional biomanipulation. Compared with deep lakes, wax and wane of phytoplankton due to alternations in the ecosystem structure is also able to exert significant influences on the P exchange at the sediment-water interface in shallow lakes. In other words, biological activities are also able to drive P release from sediments, and such a static P release process is especially more prominent in eutrophic shallow lakes with dense phytoplankton. 相似文献
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The water quality of Lake Taihu has declined markedly in the past two or three decades. We used modern non-parametric statistical methods to analyse the water quality record for 1989-1993 (samples collected at 2-monthly intervals). Phytoplankton blooms have been a particular problem, as the very high peak chlorophyll a concentrations in the Meiliang (up to 0.4 g·m-3) and the coastal regions (up to 0.5 g·m-3) indicate. However, over a large area of the middle of the lake, peak chlorophyll a concentrations were much lower (0.01-0.03 g·m-3). In this deeper, turbid part of the lake there may often be insufficient underwater light to support rapid phytoplankton growth; grazing by the abundant benthic bivalves may also be important. Total phosphorus (P) concentrations in the coastal waters increased significantly (p < 5%). Suspended solids concentrations also increased significantly, and as a result transparency decreased. However, phytoplankton probably usually only account for a small proportion of the suspended material, so the parallel increase in total P and suspended solids may be coincidental. Significant increases in chlorophyll a were not observed, but phytoplankton blooms are often short-lived (e.g. days to weeks), and thus may not always be detected by the 2-monthly sampling. 相似文献
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蓝藻的防控与治理是湖泊水环境、水生态管理的重要内容,实时获取蓝藻的空间分布信息对于降低蓝藻灾害风险具有重要意义.针对地面调查费时费力、卫星遥感监测粒度较粗且时效性不强等问题,本文提出了一种基于视频监控网络的湖泊蓝藻实时监测技术.基于环巢湖视频监控网络的33个功能摄像机,研究如何从视频图像中实时、准确提取蓝藻的分布信息.为克服不同摄像头的观测角度不一致、光照强度和背景条件不一致等诸多挑战,在视频图像蓝藻表征分析的基础上,通过多尺度深度网络进行图像粗粒度分类,区分蓝藻与浑浊、阴影水体;基于随机森林进行蓝藻精细化识别,克服蓝藻的强异质性.最后以渔政站沿岸水域的日均蓝藻覆盖率和月均蓝藻覆盖率为统计单位,开展了巢湖沿岸蓝藻的动态监测.研究成果可为科学制定蓝藻治理方案提供技术支撑. 相似文献
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三峡水库支流小江富营养化模型构建及在水量调度控藻中的应用 总被引：2，自引：1，他引：1
三峡水库蓄水以来,支流小江呈富营养化加重的趋势,且多次暴发春季水华.水库蓄水以后支流流速变缓,水体滞留时间增加,是引发支流水华的主要因素之一.基于MIKE软件,建立小江调节坝下游至河口的二维水动力-富营养化模型,考虑碳、氮、磷3种元素在浮游植物有机体、死亡腐屑和无机盐中的循环转化,模拟小江河段的春季水华过程.分析小江生态调节坝的水量调节抑藻作用,即人为制造"洪水脉冲",增加短时间内的水流流速,对下游流场进行扰动以控制水华.计算结果表明,增大泄水量对调节坝下游的小江河段的春季藻华总体上具有一定的抑制作用.小江上游河段调度作用效果明显,下游高阳至入汇口河段调节作用较小,上游调节坝水力调度可以作为三峡水库支流水华应急治理措施之一.营养盐控制应该是控制支流水华的根本措施. 相似文献
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水华的频发已成为当前三峡水库最为突出的生态环境问题之一。尽管水动力调控叠加上温度变暖和营养负荷增加会诱导水华暴发强度和频率增加,但仍缺乏有效的方法框架去利用野外观测数据评估环境因子与浮游植物间的因果关联。本研究以三峡水库澎溪河监测数据为例,采用非线性时序分析的建模框架来量化浮游植物的因果响应规律。数据来自于2007年6月至2018年9月澎溪河流域的高阳平湖和汉丰湖两个观测点,其中包含了水文、气象和水质及叶绿素a等11种变量。首先,利用奇异谱分析(SSA)分离了叶绿素a和环境因子的低维确定性动力学信号;其次,采用收敛交叉映射(CCM)方法检验了叶绿素a与环境因子间的因果关联。结果显示:(1)气象因子、支流流量、水温、三峡大坝水位和上游调节坝水位是影响高阳平湖叶绿素a时序变化的重要因素;(2)总氮、总磷为代表的营养盐只在汉丰湖观测点中表现出与叶绿素a的因果关系,且总氮较之于总磷对叶绿素a变化影响更为显著;(3)CCM结果与传统的皮尔森相关性分析及格兰杰因果检验比较,证实非线性时序分析方法在分析浮游植物的因果响应上更具优势。本研究为水生态系统的因果建模提供了研究范例,也为推动利用长期观测数据... 相似文献
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Marginal ice edge zones (MIZ) are unique frontal systems with air-ice-sea interfaces. Phytoplankton blooms, which occur along the edge of the melting ice pack in spring, are strongly related to the air-ice-sea interactive processes. In spring 1982, during a cruise to the Bering Sea ice pack, hydrographic sections, including standard biological oceanographic parameters, were collected across the MIZ showing such enhanced phytoplankton bloom populations in the ice edge. During this period the ice edge retreated at speeds of 6 to 38 cm s?1. Associated with the retreating ice edge were a faster moving upper layer oceanic front that kept pace with the retreating ice edge, and a nearly stationary deeper front. In the presence of light, the phytoplankton blooms are shown to be associated with, and primarily controlled by enhanced density stratification and frontal structure due to ice melt during the spring ice retreat. The ice melt water forms stratification that helps to maintain the phytoplankton within the photic zone. The ice edge blooms can be differentiated from open water blooms by the stratification mechanism; in MIZ blooms stratification is due to low salinity melt water as opposed to temperature derived stratification in most open water blooms. In addition, in the series of cross sections collected, a unique biophysical interaction was observed when the MIZ front moving north with the spring retreat, came in contact with a fixed shelf front forming a ‘dish’ shaped hydrographic structure within which a major phytoplankton bloom was observed. We suggest that upwelling from the tidally driven shelf front supplied nutrients to the surface waters extending the life of the bloom. Wind-driven ice edge upwelling was also observed but was difficult to distinguish from the shelf front circulation.In this same set of ice edge cross sections, a cold water mass was observed at the surface in the MIZ. This water mass was subsequently overridden by warmer water forming a cold tongue structure above the pycnocline and seaward of the shelf front. We suggest that this cold tongue was transient in nature, and illustrative of one mechanism by which the T-S characteristics of high latitude shelf waters are formed and altered. 相似文献
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《Limnologica》2021
Inlay Lake is the second largest natural lake in Myanmar. Located in Shan State, in the eastern part of the country, it is a known biodiversity hotspot. The lake is negatively affected by an increasing local human population and rapid growth in both agriculture and tourism. In recent decades, several studies have listed faunistic and floristic groups in Inlay Lake, but there is still a general lack of knowledge about the aquatic macrophyte and phytoplankton community composition and abundance, and their interactions. To fill this knowledge gap, field surveys of biological and physical and chemical parameters were carried out in the period 2014–2017. They show that Inlay Lake is a shallow, clear water and calcareous lake, with nutrient concentrations indicating mesotrophic-eutrophic conditions. However, close to the shore, nutrient concentrations are generally higher, reflecting pollution from inflowing rivers, shoreline villages and floating gardens. Both the richness and abundance of aquatic macrophytes in Inlay Lake were high, with several species forming extensive stands in most of the lake over the whole survey period. Total phytoplankton and cyanobacterial biomass were low, but cyanobacteria included toxin-producing strains of Microcystis, suggesting that cyanobacterial and total phytoplankton biomass need to be kept low to avoid potentially harmful cyanobacterial blooms. Submerged macrophyte abundance and phytoplankton biomass were inversely correlated in the heavily vegetated northern lake area. Our survey suggests a great importance of the submerged macrophytes to the general water quality and the clear water state in Inlay Lake. Maintaining high macrophyte abundances should therefore be a goal in management strategies, both for Inlay Lake and other lakes in Myanmar. It is highly desirable to include macrophytes and phytoplankton in the lake monitoring in Myanmar. 相似文献
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《Limnologica》2017
Macrophytes and phytoplankton including cyanobacteria are main primary producers in aquatic environments.Macrophytes can maintain water quality by suppressing phytoplankton growth through a number of mechanisms: while e.g. the absorption of high amounts of nutrients and the provision of refuge from predation for herbivorous aquatic fauna are widely accepted macrophyte functions, the role of their release of allelopathic substances in suppressing phytoplankton is increasingly being studied. Some macrophyte species can support the growth of epiphytic cyanobacteria providing them an advantage over planktonic species in the competition for nutrients. On the other hand, some cyanobacteria dominate in eutrophic water bodies and produce cyanotoxins that exert allelopathic substances which may contribute to the decline of macrophytes. Macrophytes can interact with these cyanotoxins in different ways including bioaccumulation and biotransformation. This review focuses on such allelopathic interactions between macrophytes and toxic cyanobacteria. The article also suggests methods for researchers and water resources managers for the application of macrophytes to control harmful cyanobacterial blooms and as phytoremediators for toxin elimination from water bodies. 相似文献
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The availability and partition of nitrogen (N) and phosphorus (P) in inorganic and organic compartments, as well as their stoichiometric ratio, are influenced by both physical and biological forcing factors. On this basis, the temporal and spatial dynamics in N:P atomic ratios in different compartments may provide information on the functioning of marine ecosystems. Here we explore the relative importance of water temperature, river inputs, wind mixing, stratification, ingression of nutrient-depleted Eastern Adriatic Current and phytoplankton biomass on concentrations and ratios between nitrogen and phosphorus in a semi-enclosed bay (the Gulf of Trieste), using data from monitoring programs carried out during 8 years. Water samples are first classified in 6 water types based on N:P ratios in different components, and then relationships between water type space-time distribution and a set of forcing factors is sought. Results show that the gulf is characterised by relatively stable N:P ratios in all compartments (about 23-26), always exceeding the classical Redfield ratio. In the surface layer, however, nitrogen and phosphorus dynamics are decoupled because of river input and plankton productivity, and a significant spatial and temporal variability is observed in terms of stoichiometric balance, nutrient concentrations and partition among the different pools. Deviations from stable N:P ratios follow a seasonal evolution. In spring, continental inputs alter inorganic nutrient compartments (N:P up to 115); later on, during the seasonal succession of biological processes (e.g. late spring phytoplankton blooms, summer increase in microbial activities and autumn phytoplankton blooms), a change is also seen in the organic dissolved and particulate pools. Multivariate statistical analysis suggests that, among the considered forcing factors, the most relevant in modulating the N:P stoichiometry in the Gulf of Trieste are river inputs and ingression of the Eastern Adriatic Current (acting in opposite directions) along with phytoplankton dynamics. During the whole period, besides variations in N:P stoichiometry, in the Gulf of Trieste dissolved organic matter represents the largest pool of N and P, which can provide a source of nutrients for the planktonic community alternative to inorganic nutrient. 相似文献
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《Marine pollution bulletin》2009,58(6-12):236-244
Due to growing concerns regarding persistent organic pollutants (POPs) in the environment, extensive studies and monitoring programs have been carried out in the last two decades to determine their concentrations in water, sediment, and more recently, in biota. An extensive review and analysis of the existing literature shows that whilst the vast majority of these efforts either attempt to compare (a) spatial changes (to identify “hot spots”), or (b) temporal changes to detect deterioration/improvement occurring in the environment, most studies could not provide sufficient statistical power to estimate concentrations of POPs in the environment and detect spatial and temporal changes. Despite various national POPs standards having been established, there has been a surprising paucity of emphasis in establishing accurate threshold concentrations that indicate potential significant threats to ecosystems and public health. Although most monitoring programs attempt to check compliance through reference to certain “environmental quality objectives”, it should be pointed out that many of these established standards are typically associated with a large degree of uncertainty and rely on a large number of assumptions, some of which may be arbitrary. Non-compliance should trigger concern, so that the problem can be tracked down and rectified, but non-compliance must not be interpreted in a simplistic and mechanical way. Contaminants occurring in the physical environment may not necessarily be biologically available, and even when they are bioavailable, they may not necessarily elicit adverse biological effects at the individual or population levels. As such, we here argue that routine monitoring and reporting of abiotic and biotic POPs concentrations could be of limited use, unless such data can be related directly to the assessment of public health and ecological risks. Risk can be inferred from the ratio of predicted environmental concentration (PEC) and the predicted no effect concentration (PNEC). Currently, the paucity of data does not allow accurate estimation of PNEC, and future endeavors should therefore, be devoted to determine the threshold concentrations of POPs that can cause undesirable biological effects on sensitive receivers and important biological components in the receiving environment (e.g. keystone species, populations with high energy flow values, etc.), to enable derivation of PNECs based on solid scientific evidence and reduce uncertainty. Using the threshold body burden of POPs required to elicit damages of lysosomal integrity in the green mussel (Perna virvidis) as an example, we illustrate how measurement of POPs in body tissue could be used in predicting environmental risk in a meaningful way. 相似文献