Historical fluxes of metal and metalloids in an aquatic ecosystem affected by land-use change and mining activities in northwestern Mexico     

《国际泥沙研究》2023,38(5):724-738

Freshwater reservoirs are essential owing because of their ecological, economic, and social importance. They are particularly vulnerable to contamination, as of metal and metalloids, derived from anthropogenic activities like mining. The temporal variations in trace element concentrations (arsenic (As), mercury (Hg), chromium (Cr), copper (Cu), nickel (Ni), lead (Pb), and zinc (Zn)), enrichment, fluxes, and possible sources were evaluated by studying two sediment cores from the La Angostura (ANG) Reservoir (northwest Mexico), using ²¹⁰Pb geochronology. The enrichment factors showed from null to minor enrichment for most elements, but moderate to severe enrichment of mercury (Hg). Most trace element concentrations had a detrital origin, and notable Hg concentration increases since the past decade were associated with severe drought periods, likely resulting from wildfires. The observed sediment concentrations of As and Hg can cause adverse effects on biota in the ecosystem since they are above the probable effect level (PEL). Development of strategies for metal attenuation in this reservoir is recommended and metals should be controlled until specific ecotoxicological studies are performed.  相似文献   

太湖康山湾示范区水生植物对水体氮、磷控制的适用性分析   总被引：2，自引：1，他引：1  

宋玉芝  朱广伟  秦伯强 《湖泊科学》2013,25(2):259-265

为重建湖泊水生植被,改善太湖局部水域水质,在太湖康山湾示范区两个大型围隔进行了两种类型水生植物重建.通过2010年8月-2011年8月的现场采样及分析测定发现,人工控制条件下,浮叶植物荇菜和菱以及沉水植物马来眼子菜的重建效果较好,在其生长季节具有较高的覆盖度;研究表明,控制风浪及提高透明度是恢复水生植被的前提;植被重建区沉水植物氮、磷含量与浮叶植物差别不大,但浮叶植物重建区水体氮、磷浓度的控制比沉水植物重建区好;从经济及水环境效益角度来看,太湖敞水区的沿岸带由于风浪的控制比较困难,恢复水生植被时,应选择浮叶植物荇菜、菱、沉水植物马来眼子菜等抗风浪能力强的物种.本研究为太湖敞水区沿岸带的生态恢复方案制定提供了理论依据.  相似文献   

Seasonal insect emergence from three different temperate lakes     

《Limnologica》2017

Knowing the aquatic resources, such as emerging insects, that are entering terrestrial systems is important for food web and conservation studies, especially when water availability or quality is limited. Even though studies concerning benthic macroinvertebrates are numerous, insect emergence from lakes is less studied.To understand if water parameters (e.g., water temperature, oxygen concentration etc) determine insect emergence and the possible seasonal differences, we collected emergent insects from three different lakes in South Germany, during three seasons. We searched for common patterns of insect emergence at the three lakes. Moreover, the relative contribution of insects of aquatic origin to aerial flying arthropods was assessed, with collecting aerial flying arthropods at the shore.Chironomidae constituted the highest number of emerged insects in all lakes, however different patterns of emergence occurred in each lake (unimodal vs. bimodal) with different season-dependent times for the emergence peaks (spring, summer, beginning of autumn). Aquatic insects constituted a considerable proportion (at least 17%) of the aerial flying arthropods at the shore. The variation in insect emergence was explained by water temperature, however not by other water parameters or the nutrient values. Seasonal and spatial differences in insect emergence, should be considered when investigating aquatic-terrestrial interactions and designing conservation plans. A total biomass of up to 1.8 g m⁻² of emerging insects from the littoral zone of Lake Constance can enter the terrestrial system in a year. We also provide length-dry weight relationships for emerged (adult) Chironomidae. These equations are useful to estimate the dry insect biomass from length data and currently such data lack for adult aquatic insects.  相似文献   

富营养化湖泊围隔中重建水生植被及其生态效应   总被引：1，自引：0，他引：1  

胡旭  何亮  曹特  倪乐意  谢平 《湖泊科学》2014,26(3):349-357

水体富营养化导致水生植被衰退、蓝藻水华暴发、水质恶化和水生生态系统崩溃.恢复水生植被被认为是改善受损水体水质和提高其生态系统稳定性的重要手段.本研究通过构建大型围隔,根据水生植物的耐污程度及其对水质和底质等条件的需求,选取几种适宜的水生植物在围隔内进行移栽与群落构建,并以不移栽水生植物的围隔和围隔外水体作为对照.实验期间(2011年4月至2012年6月),围隔内移栽的几种水生植物全部存活,并建立了相对稳定的群落.同时还跟踪监测了3个处理组的水质情况,结果显示,移栽水生植物的围隔内水质明显优于围隔外,与未移栽水生植物围隔相比,也有很大程度的改善,其中移栽水生植物围隔内水体的总氮、铵态氮、总磷、水下消光系数相比于围隔外水体分别低30.55%、44.09%、36.04%和42.13%,相比于未移栽水生植物围隔内水体分别低5.96%、13.40%、6.70%和7.60%,透明度分别比围隔外水体和未移栽水生植物围隔水体高74.59%和8.70%,浮游植物生物量也大大低于围隔外,而浮游动物生物量却明显高于后者.此外,实验后移栽水生植物围隔内沉积物氮、磷含量及其间隙水总氮、总磷、铵态氮浓度明显低于围隔外和未移栽水生植物围隔.研究表明,在富营养化浅水湖泊中通过建立围隔进行合理的群落配置,进而逐步恢复水生植物是完全可行的,而水生植物恢复后加强对其管理和维护至关重要.  相似文献   

大通湖及东洞庭湖区生物体重金属的水平及其生态评价   总被引：4，自引：0，他引：4  

祝云龙  姜加虎  黄群  孙占东  王红娟 《湖泊科学》2007,19(6):690-697

于2005年11月采集了大通湖及东洞庭湖区湖水和水生生物样品,并测定了水和水生生物样品中重金属(Cd、Pb、Hg、As)的含量,并对湖区生物体重金属进行了污染评价.研究结果表明,大通湖及东洞庭湖区湖水中重金属含量较小,绝大部分采样点水质都属于国家Ⅰ类水标准;水生生物体内CD、Pb含量为虾＞螺＞鱼,Hg的含量为鱼＞螺＞虾,As的含量为螺＞虾＞鱼;而鱼类重金属含量则为底栖鱼类＞中上层鱼类,肉食性鱼类＞植食性鱼类.大通湖及东洞庭湖区生物体中CD、Pb的污染指数为虾＞螺＞鱼,Hg的污染指数则为鱼＞螺＞虾,As的污染指数则为螺＞虾＞鱼.  相似文献   

Toxicity studies of elemental sulfur in marine sediments     

Monika Cieszynska-Semenowicz  Justyna Rogowska  Wojciech Ratajczyk  Joanna Ratajczyk  Lidia Wolska 《国际泥沙研究》2018,33(2):191-197

Elemental sulfur(ES) is a component essential for proper development of animals, but it can be toxic for aquatic organisms. The objectives of the study reported here included determination of ES concentrations in sediment collected in the area of the Gulf of Gdansk(Baltic Sea) and search for the possible correlations with the ecotoxicity results. Sediment samples were collected from four locations: the Vistula River mouth, in the Port Basin, in the area of discharge of the treated wastewater from the Wastewater Treatment Plant(WWTP) and in the area of the sunken World War Ⅱ s/s 'Stuttgart' shipwreck. The levels of elemental sulfur were determined using a gas chromatograph coupled with a mass spectrometer(GC-MS). Toxicity of marine sediment samples was estimated for three biotest organisms-bioluminescent bacteria Vibrio fischeri, crustacean Heterocypris incongruens, and Synapis alba plant. The highest toxicity of sediments for all indicator organisms was observed in samples taken at the place of the shipwreck(2-100%). The same samples had a high sulfur content(16.7-143.2 μg/g dry weight(d.w.))therefore, it was decided to investigate whether the presence of ES in the sediment in the studied area can have an impact on the results of the ecotoxicity determination in real samples. However, the removal of sulfur from the samples resulted in no significant changes in the level of toxicity of the samples. In this research it could not be confirmed that the presence of elemental sulfur is the only factor responsible for the observed sediment toxicity. It seems that other compounds or their mixtures present in the sediment may have a significant influence on the results obtained.  相似文献   

POTENTIAL EFFECTS OF CLIMATE CHANGE ON FRESHWATER ECOSYSTEMS OF THE NEW ENGLAND/MID-ATLANTIC REGION     

MARIANNE V. MOORE  MICHAEL L. PACE  JOHN R. MATHER  PETER S. MURDOCH  ROBERT W. HOWARTH  CAROL L. FOLT  CELIA Y. CHEN  HAROLD F. HEMOND  PATRICIA A. FLEBBE  CHARLES T. DRISCOLL 《水文研究》1997,11(8):925-947

Numerous freshwater ecosystems, dense concentrations of humans along the eastern seaboard, extensive forests and a history of intensive land use distinguish the New England/Mid-Atlantic Region. Human population densities are forecast to increase in portions of the region at the same time that climate is expected to be changing. Consequently, the effects of humans and climatic change are likely to affect freshwater ecosystems within the region interactively. The general climate, at present, is humid continental, and the region receives abundant precipitation. Climatic projections for a 2 × CO₂ atmosphere, however, suggest warmer and drier conditions for much of this region. Annual temperature increases ranging from 3–5°C are projected, with the greatest increases occurring in autumn or winter. According to a water balance model, the projected increase in temperature will result in greater rates of evaporation and evapotranspiration. This could cause a 21 and 31% reduction in annual stream flow in the southern and northern sections of the region, respectively, with greatest reductions occurring in autumn and winter. The amount and duration of snow cover is also projected to decrease across the region, and summer convective thunderstorms are likely to decrease in frequency but increase in intensity. The dual effects of climate change and direct anthropogenic stress will most likely alter hydrological and biogeochemical processes, and, hence, the floral and faunal communities of the region's freshwater ecosystems. For example, the projected increase in evapotranspiration and evaporation could eliminate most bog ecosystems, and increases in water temperature may increase bioaccumulation, and possibly biomagnification, of organic and inorganic contaminants. Not all change may be adverse. For example, a decrease in runoff may reduce the intensity of ongoing estuarine eutrophication, and acidification of aquatic habitats during the spring snowmelt period may be ameliorated. Recommendations for future monitoring efforts include: (1) extending and improving data on the distribution, abundance and effect of anthropogenic stressors (non-point pollution) within the region; and (2) improving scientific knowledge regarding the contemporary distribution and abundance of aquatic species. Research recommendations include: (1) establishing a research centre(s) where field studies designed to understand interactions between freshwater ecosystems and climate change can be conducted; (2) projecting the future distribution, activities and direct effects of humans within the region; (3) developing mathematical analyses, experimental designs and aquatic indicators that distinguish between climatic and anthropogenic effects on aquatic systems; (4) developing and refining projections of climate variability such that the magnitude, frequency and seasonal timing of extreme events can be forecast; and (5) describing quantitatively the flux of materials (sediments, nutrients, metals) from watersheds characterized by a mosaic of land uses. © 1997 John Wiley & Sons, Ltd.  相似文献   

人地复合生态系统韧性研究进展及其对海岸带生态系统韧性研究的启示     

刘永超  张海涛  应超  李加林 《海洋通报》2024,(3):415-425

在全球气候变化与人类高强度开发的双重影响下,人地复合生态系统和受陆海系统交互影响的海岸带地区生态脆弱性更加明显。如何有效把握人地复合生态系统发展动向,合理规划与调控社会经济活动、促进人地关系协调发展一直是可持续发展领域研究的重点课题。韧性作为系统的内在特征,在防范化解灾害风险、维护区域生态安全中发挥着重要作用,是人地复合生态系统可持续发展能力的重要表现。然而,目前关于人地复合生态系统韧性的内涵、评估方法等方面尚未形成统一的范式,韧性的量化评估方法存在较大差异。通过梳理和归纳现有研究成果认为,韧性经历了从工程韧性、生态韧性到演进韧性的转变,其概念及内涵仍在不断拓展与深化;总结对比了基于过程形成性和状态总结性的韧性评估方法发现,将韧性作为过程与结果的综合评估研究仍较为缺乏;在抵抗扰动、维持稳定和协调发展的韧性理念下,生态系统的保护与修复等将是区域可持续发展应用中人地复合生态系统安全的重要保障。根据人地复合生态系统韧性研究进展的分析结果,结合海岸带生态系统韧性研究的现状及不足,认为未来需要在加强海岸带生态系统韧性内涵挖掘、完善海岸带生态系统韧性评价体系、提高海岸带生态系统韧性监测精度、促进学...  相似文献   

湖沼学是研究内陆水体的多学科整合科学——兼论我国湖沼学发展面临的挑战与机遇   总被引：1，自引：0，他引：1  

刘正文  苏雅玲  杨柳 《湖泊科学》2020,32(5):1244-1253

湖沼学是研究内陆水体的多学科交叉综合性科学,自从Forel F.A.于1892年首次对湖沼学做出定义以来已有近130年历史.湖沼学的主要分支学科包括地质湖沼学(包括古湖沼学)、物理湖沼学、化学(生物地球化学)湖沼学和生物湖沼学.湖沼学的关键自然属性是通过跨学科的整合,从水生态系统水平综合分析相关过程与机理,并对生态系统变化进行预测.因此,湖泊学也是支撑水资源与生态系统保护、管理与修复的核心科学.然而,目前我国湖沼学发展面临分支学科发展不平衡、研究碎片化等问题,而人类活动加剧和气候变化对内陆水体生态系统的影响及管理对策是湖沼学研究面临的挑战与机遇.我国湖沼学研究亟需围绕人类活动、气候变化的影响,重点开展以下几个方面的工作:1)水动力与水文地貌特征变化及其环境生态效应; 2)营养盐和有机质生物地球化学循环及其环境生态效应; 3)食物网结构与功能; 4)外来入侵物种的影响与控制对策; 5)与水环境有关的传染病防治; 6)地表水生态评价; 7)生态系统演变机理与退化生态系统修复等.  相似文献   

湖滨带芦苇恢复过程中沉积物氮赋存形态及含量变化:以巢湖为例   总被引：1，自引：0，他引：1  

余居华  王乐豪  康得军  郑恭毅  郭宝玲  钟继承  郑祥洲  张玉树  蔡远松  丁洪 《湖泊科学》2021,33(5):1467-1477

水生植被对于维持水生态系统结构和功能稳定性具有举足轻重的作用,而重建水生植物被认为是污染湖泊生态修复的重要手段.氮素是水生态系统重要的限制性元素之一,根着挺水植物生长发育无疑将深刻地影响着沉积物氮的迁移转化过程,但水生植物不同生长阶段对沉积物氮的需求和植物代谢强度均不同,目前对挺水植物完整生长过程中沉积物氮组分及含量变化认识仍十分不足.本研究通过为期120d的沉积物柱芯培养和水槽模拟试验,探究巢湖芦苇恢复完整生长过程中沉积物总氮(TN)、无机氮(TIN)与可转化态氮(TF-N)的变化及其关键调控因子.结果表明,芦苇完整生长过程将持续激发沉积物氮活性,沉积物TIN与TF-N含量逐渐增加,而沉积物TN和非可转化态氮(NTF-N)含量显著降低.模拟试验期间,指数型增长的芦苇生物量提高了沉积物铵态氮(NH_4~+-N)和硝态氮(NO_3~--N)含量,但亚硝态氮(NO_2~--N)含量却逐渐降低;与第0天相比,第120天沉积物离子交换态氮(IEF-N)、碳酸盐结合态氮(CF-N)、铁锰氧化态氮(IMOF-N)和有机态及硫化物结合态氮(OSF-N)含量分别增加了 1.10、3.40、3.60和1.40倍,这主要受芦苇吸收利用、根系代谢强化根际沉积物氧化还原电势和改变pH微环境共同驱动.在第120天,沉积物NH_4~+-N和NO_3~--N含量急剧升高,分别是第90天的9.43和2.22倍,表明芦苇衰亡凋落过程将向沉积物释放大量的TIN,故需要综合采取湖泊物理—生态工程手段来有效管控芦苇枯落物,从而提升水生植被修复效果并构建长效稳态机制.  相似文献