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1.
In the joint estuary of the Odiel and Tinto rivers (SW Spain), the invasive Spartina densiflora Brongn. and the native Spartina maritima (Curtis) Fernald are growing over sediments with extreme concentrations of heavy metals. The contents of As, Cu, Fe, Mn, Pb and Zn were determined in sediments, rhizosediments and different tissues of both species, from Odiel and Tinto marshes. S. densiflora showed a higher capability to retain metals around their roots and to control the uptake or transport of metals, mediated by a higher formation of plaques of Fe/Mn (hydro) oxides on the roots. At the Tinto marsh, there were no differences between the metal concentrations of the sediment and those of the rhizosediment, a fact that could be explained by the extremely high concentrations of metals which can pass over a threshold value, altering the properties of root cells and preventing roots from acting as a ‘barrier’ to the uptake or transport of metals.  相似文献   

2.
The halophytic shrub Halimione portulacoides demonstrates a high tolerance to heavy metal contamination and a capacity for accumulating metals within its tissues. On the Iberian Peninsula, this species has colonized habitats with high levels of metal pollution. The aim of this study is to analyze the response of H. portulacoides stem cuttings to this pollution. Growth, photosynthesis and metal uptake were examined in H. portulacoides through an experiment in which stem cuttings were replanted in metal-contaminated soil. This condition decreased growth and lowered both photosynthetic rate and stomatal conductance. Reduced photosynthetic performance was largely due to the reduced concentration of photosynthetic pigments. Despite these responses, there was some important evidence suggesting the phytoremediatory potential of Halimione stem cuttings. The results of our study indicate that this salt-marsh shrub may represent a biotool of value in the restoration of polluted areas.  相似文献   

3.
《Marine pollution bulletin》2013,71(1-2):119-124
The influence of different concentrations (10–2000 μM) of heavy metals (Cu, Mn, Ni, Zn) was analysed in Atriplex halimus and Salicornia ramosissima germination pattern and seedling size. They are two halophyte species that grow in the Estuary of Huelva (Southwest Iberian Peninsula, Spain), one of the most heavy metal-polluted environments in the world.All of the metals tested affected the final germination percentage in A. halimus and only Ni reduced germination in S. ramosissima. The germination rate was unaffected in both species.The study of seedling development shows that S. ramosissima, an intertidal annual species, has a higher tolerance of metals than A. halimus, a bush that inhabits the upper part of the marshes.Taking into account the metal concentrations in the estuary and the effects of these on the seedling development of the species analysed, we conclude that metals might limit plant colonisation in some parts of the marshes.  相似文献   

4.
为探究重污染底泥对沉水植物繁殖体萌发和幼苗生长影响,以苦草（Vallisneria natans）种子和黑藻（Hydrilla verticillata）冬芽为研究对象,以轻污染底泥为对照组,通过室内模拟实验研究了重污染底泥对两种繁殖体萌发和幼苗生长、生理特性的影响。实验结果表明,与轻污染底泥相比,重污染底泥对苦草种子萌发和幼苗生长无显著影响。黑藻冬芽萌发和幼苗地上部生物量在两组间没有显著差异,但重污染底泥组幼苗的地下部生物量显著高于轻污染底泥组,其地上部和地下部生物量比值由7.06±0.38下降至2.97±0.08。此外,苦草和黑藻幼苗受到重污染底泥胁迫表现出不同的生理响应。苦草幼苗叶片的类胡萝卜素含量显著减少,可溶性糖和蛋白含量分别降低11.56%、24.10%,根系活力也明显受到抑制,仅为（34.93±3.28） mg/（g·h）;黑藻幼苗生理响应与苦草略有不同,其叶片的叶绿素a、b含量显著增加,根系活力降低44.29%,可溶性糖和蛋白含量在轻污染组和重污染组之间无显著差异。由此可见,重污染底泥对苦草种子和黑藻冬芽的萌发影响不显著,但会明显影响幼苗的生长发育和生理特性,研究结果为...  相似文献   

5.
The present study was conducted to investigate the tolerance of Spartina densiflora to phenanthrene, and to test its ability in phenanthrene dissipation. A glasshouse experiment was designed to investigate the effect of phenanthrene from 0 to 1000 mg kg−1 on growth and photosynthetic apparatus of S. densiflora by measuring chlorophyll fluorescence parameters, gas exchange and photosynthetic pigments. We also performed chemical analysis of plant samples, and determined the concentration of phenanthrene remaining in soil. S. densiflora survived to concentrations as high as 1000 mg kg−1 phenanthrene in soil; in fact, there was no significant difference in RGR among the treatments after 30 days. Otherwise, phenanthrene affected photosynthetic apparatus at 100 and 1000 mg kg−1; thus, the lower ΦPSII could be explained by the declined photosynthetic pigment concentrations. Soil extraction indicated a more marked rate of phenanthrene disappearance in the soil in the presence of S. densiflora.  相似文献   

6.
In order to investigate the pollution levels, sources and ecological risks of arsenic (As) and heavy metals (Cr, Ni, Cu, Zn, Pb and Cd) in inshore sediments of the Yellow River estuary, the surface sediment in areas of inshore coastal waters were sampled in October 2014 as the flow-sediment regulation project (FSRP) was implemented for 13 years. Results showed that the concentrations of As and heavy metals in inshore sediments of the Yellow River estuary were in the order of Zn?>?Cr?>?Cu?>?Ni?>?Pb?>?As?>?Cd. Higher levels of As, Cr, Ni, Cu, Zn and Pb generally occurred in fine-grained sediments of the Yellow River estuary and the southeast region, which was consistent with the spatial distribution of clay. In contrast, higher concentrations of Cd were generally observed in northwest area of the Yellow River estuary and near the Qingshuigou estuary, which showed similarly spatial distribution with that of sand. The sediment quality guidelines (SQGS) and geoaccumulation indices (Igeo) indicated that the inshore sediments were polluted by Cu, Cd, As, Pb and Zn, and, among them, Cd pollution was more serious. Ecological risk indices (E r i ) demonstrated low risks for Cr, Ni, Cu, Zn, Pb and As, and high potential toxicity by Cd. The integrated ecological risk index implied that 6.8% of stations presented moderate risk, 4.5% of stations exhibited disastrous risk, and 88.7% of stations demonstrated considerable risk. Principal component analysis indicated that Ni, Cu, Zn, Pb and As might originate from common pollution sources, while Cr and Cd might share another similar sources. With the continuous implementation of FSRP, As and heavy metal levels in inshore sediments of the Yellow River estuary could be classified as stage I (2002–2010) and stage II (2010–2014). In the stage I, As, Cr, Ni, Cu, Zn and Pb levels fluctuated but decreased significantly, whereas Cd concentrations showed little variation. In the stage II, As and heavy metal levels significantly increased although some little fluctuations occurred. The continuous accumulation of As and heavy metals (especially for Cd) in inshore sediments of the Yellow River estuary would occur again as the FSRP was implemented for 9 years (since 2010). The ecotoxicological risk of Cd, As, Ni and Cu in inshore sediments might be more serious since the accumulation of the four elements would be continuously occurred in future years. Next step, there will be long-term potential consequences for marine organism if effective measures are not taken to control the loadings of metal pollutants into estuary.  相似文献   

7.
In this paper, we analyze two short cores collected in the Tinto estuary (SW Spain), and describe the palaeoenvironmental evolution of this area during the last two millennia, along with the influence of historical mining activities and recent industrial pollution on sediments and microfauna (foraminifera and ostracoda). Although there were no significant changes in the distribution of microorganisms, a first pollution period (0-150 AD) was recorded in high sediment pollution by Cu in the shallow palaeochannels of the middle estuary. During this period and the following 1700 years, tolerant pioneer species of both foraminifera and ostracoda were found predominantly in the inner, protected areas of the estuary, while the bottom sediments were subjected to high hydrodynamic gradients, and consequently showed lower density and diversity of organisms. In the last 150 years, acid mine drainage processes, introduction of a new mining period, and the polluted inputs derived from two industrial processes resulted in increased heavy metal contamination of the bottom sediments, and corresponding extirpation of ostracodes and restriction of foraminifers to the inner zones of the estuary.  相似文献   

8.
水生植物是湖泊生态系统的重要组成部分,沉积物-水界面是湖泊生态系统中营养盐循环的重要界面,因而研究水生植物对沉积物-水界面微观剖面的影响具有重要意义.本文利用轮叶黑藻作为研究对象,研究了来自于香溪河、太湖和东湖3个样点的沉积物及上覆水中N、P等理化性质,并利用微电极研究轮叶黑藻对3种沉积物-水界面微观剖面是否有影响.实验结果表明:轮叶黑藻生长迅速.增长率因沉积物不同而不同,有一定的耐污能力;轮叶黑藻使水体和沉积物中总氮、总磷含量减少,对水体和底泥有一定的净化作用;轮叶黑藻可使水体溶解氧升高,并使沉积物有氧层厚度增加,改变沉积物的氧化还原电位;轮叶黑藻可能改变了根际微环境中微生物的数量和种类,而使沉积物和上覆水中的pH、N2O和H2S等发生变化.  相似文献   

9.
Sublethal effects of estuarine sediments containing high levels of heavy metals were studied using the marine bivalve, Macoma balthica. Burrowing behaviour was inhibited in all contaminated sediments compared to the control. The time required for 50% of the population to burrow (ET50) ranged from 0.17 h in the control to 4.8 h in the most contaminated substrate. A comparison of linear regressions of the concentrations of individual metals in the sediments vs the burrowing response times showed the regressions for mercury and cadmium to be significant (P < 0.05 and < 0.001 respectively). An active threshold avoidance response by burrowed M. balthica was also demonstrated as clams showed a significant (P < 0.05) avoidance of the sediment containing the highest metal levels. Both behavioural responses were considered useful sublethal tests to assess the impact of polluted sediments.  相似文献   

10.
The toxicological state of individual parts of the Novosibirsk Reservoir was assessed with the help of bioassay tests of water and water extracts from bottom sediments with the use of two species of protococcus algae (Scenedesmus quadricauda (Turp.) Breb., Chlorella vulgaris Beijer) and two species of entomostracans (Daphnia magna Straus, Ceriodaphnia affinis Lillijeborg). It was found that the Ob R. near Kamenon-Ob is more polluted in terms of water and less polluted in terms of bottom sediments, compared with those in the lower part of the reservoir. The bioassay results are in agreement with the results of benthos-based bioindication and studies of chlorophyll a and pollutant concentrations in water.  相似文献   

11.
《Marine pollution bulletin》2012,64(5-12):528-534
The Salt-water River watershed is one of the major river watersheds in the Kaohsiung City, Taiwan. Water quality and sediment investigation results show that the river water contained high concentrations of organics and ammonia–nitrogen, and sediments contained high concentrations of heavy metals and organic contaminants. The main pollution sources were municipal and industrial wastewaters. Results from the enrichment factor (EF) and geo-accumulation index (Igeo) analyses imply that the sediments can be characterized as heavily polluted in regard to Cd, Cr, Pb, Zn, and Cu. The water quality analysis simulation program (WASP) model was applied for water quality evaluation and carrying capacity calculation. Modeling results show that the daily pollutant inputs were much higher than the calculated carrying capacity (1050 kg day−1 for biochemical oxygen demand and 420 kg day−1 for ammonia–nitrogen). The proposed watershed management strategies included river water dilution, intercepting sewer system construction and sediment dredging.  相似文献   

12.
The purpose of this study was to assess the chemical partitioning of selected heavy metals(Fe,Mn,Cu,Zn,Pb,Cr,Co and Ni) in 10 surface sediments at Tirumalairajan River Estuary in the southeastern coast of India.A five-step sequential extraction technique was used to assess the environmental status of heavy metals.Most of metals were considered to be immobile due to the high availability in the residual fraction of heavy metals.The sediments of Tirumalairajan River estuary had not been polluted by heavy metals,and they didn’t pose any high ecological risk.The seasonal variations of heavy metals were slightly higher in summer than in monsoon season.Factor analysis was also carned out to understand the associations of metals in different fractions with sand,silt,clay,organic matter,pH,salinity and other metals.The relationship between the Q-mode and R-mode cluster analyses was useful for identifying the pollution levels in both seasons.It was proved that the enrichment of heavy metals was related with geogenic and anthropogenic sources.The information on total metal concentrations in sediments was not sufficient for assessing the metal behavior in the environment,but the sequential extraction technique was more effective in estimating the environmental impact of contaminated sediments.  相似文献   

13.
The sediments of rivers draining areas of past mining activity in the Isle of Man contained greatly enhanced levels of zinc, lead and, to a lesser extent, copper and cadmium. This contamination extended into the estuarine harbours where it was reflected in the metal content of four species of bivalve molluscs. Of the latter, Mytilus edulis was the most useful indicator species in that it occurred in all five estuarine harbours but Scrobicularia plana, although of more limited distribution, concentrated much higher levels of zinc and lead. Individual variation of metal levels was high in all species of bivalves examined; a negative correlation of dry weight: metal content was demonstrated in many cases, but other factors may also contribute to such variation.  相似文献   

14.
Concentrations of heavy metals and polycyclic aromatic hydrocarbons (PAHs) were measured in bivalves collected in the Upper Gulf of Thailand. PAHs detected included acenaphthene, acenaphthylene, benzo[a]pyrene, fluoranthene, methylphenanthrene, phenanthrene and triphenylene. Benzo[a]pyrene was detected in all species at concentrations varying from 1.0 to 8.2 ng·g?1. Concentrations of cadmium, cobalt, copper, lead and nickel were significantly lower in bivalves from the Gulf than in green mussels collected from the mouth of the Chao Phraya River. No correlation was found between metal concentrations in animals and sediment, with the exception of copper. Copper concentrations in polychaetes and clams appeared to correlate with the copper:iron ratio of sediments. High rates of degradation were observed when radiolabelled chlorobenzene, phenanthrene and chrysene were added to water and sediment of the Chao Phraya River. Rates were lower in the waters and sediment of the Gulf of Thailand. The calculated half-lives of chlorobenzene in the Gulf of Thailand and the Chao Phraya River were about 130 and 68 days, respectively.  相似文献   

15.
ABSTRACT

The seasonal distribution of metals (V, Cr, Co, Cu, Ni, Zn, Pb, Mn, Fe, Al and Ti) in suspended and bottom sediments of four minor estuaries (Terekhol, Chapora, Sal and Talpona rivers) of Goa, India was investigated to understand the metal distribution process in the estuarine region. The highest particulate-metal concentrations were found in low-salinity regions of all the estuaries, in the wet season (e.g. in the Terekhol River, the averages in ppm were Co: 53, Ni: 197, Cu: 208, Zn: 212 and Pb: 65) compared to the dry season averages (Co: 27, Ni: 76, Cu: 105, Zn: 164 and Pb: 13 ppm). The estuarine-mixing diagrams showed non-conservative behaviour in both seasons. The Sal River had the highest particulate-metal concentration (Co: 106, Ni: 300 and Zn: 323 ppm), suggesting an anthropogenic input. The enrichment factor for suspended matter was higher than bottom sediments with extremely high enrichment for Mn (>10). The Geo-accumulation index displayed unpolluted to polluted class for all metals. The study highlights the important role played by small estuaries in seasonal metal release and accumulation along the coastal region.  相似文献   

16.
太湖宜溧河水系沉积物的重金属污染特征   总被引：83，自引：11，他引：72  
用ICP方法分析了太湖宜溧河水系沉积物中主要重金属含量,以太湖宜溧河口下层沉积物作背景样品,用均根法对沉积物中重金属进行了污染综合指数计算,并根据划分的污染等级对宜溧河水系沉积物污染状况进行了分析和评价。结果表明：宜溧河及其入湖口沉积物平均呈轻污染状态,北部支流未受污染,南部支流和太湖沿岸呈轻污染,干流河段污染最为严重,呈偏中度污染水平,在个别测点综合评价已达到重度污染状态。全水系Cu,Zn,Cd和Pb的污染指数略高。其中仅有Cd含量高出我国土壤一级自然背景值,表现为Cd污染型,其原因能与该地区水泥制造业和有色金属冶炼的污染排放有关。  相似文献   

17.
Alien plant invasions of riparian zones can trigger bottom-up effects on freshwater ecosystems through changes in leaf litter supply. Riparian zones of ponds are often invaded by alien species, and although these habitats are common, the effect of invasive alien species on ponds has rarely been studied. We performed a leaf litter experiment in a pond and compared within- and between-species variation in the breakdown rates of three native species (Alnus glutinosa, Phragmites australis and Typha angustifolia) and two aggressive alien invaders of riparian zones (Fallopia japonica and Solidago canadensis). The litter of S. canadensis decomposed faster than the litter of the other plants; more than 50 % of the S. canadensis biomass decomposed within a week. This contradicts the home-field advantage hypothesis, and we argue that the quality rather than the origin of litter might be the key factor driving breakdown rates. We also reported considerable intra-specific variation; old leaves (collected in spring after a partial aerial breakdown on stems) decomposed two to seven times slower than senescent leaves (collected in autumn just after abscission). The continuous seasonal supply of leaves of different quality into freshwaters may be disrupted by terrestrial invasions, especially if an invader forms monoculture stands and produces a highly palatable litter, as is the case with S. canadensis. This may fundamentally alter the resource dynamics in the pond environment through a rapid depletion of litter mass before the next litterfall.  相似文献   

18.
Molecular analysis was applied to characterize bacterial community structure in sediment samples collected from pristine site and oil-polluted Black Sea harbor. Amplified Ribosomal DNA Restriction Analysis (ARDRA) revealed a high similarity in the restriction patterns of both samples thus not demonstrating the effect of the pollutant on the structure of the bacterial communities. Constructed 16S rRNA gene libraries gave more detailed assessment of members. Results showed that α- and γ-Proteobacteria were dominant in the oil polluted site, whereas the pristine site was characterized by prevalence of Actinobacteria. The biodegradative potential of the adapted bacterial community in the oil-polluted sediments was demonstrated by the presence of the aromatic ring hydroxylating dioxygenase genes.  相似文献   

19.
Experiments to measure natural rates of sedimentation and to assess the tolerance of coral species to increased sedimentation were conducted at San Cristobal Reef, Puerto Rico. Sedimentation rates were measured over an 18 month period. Calcareous sediments were applied to colonies of Montastraea annularis, Diploria strigosa, D. clivosa, Acropora palmata and A. cervicornis in different frequencies and in different doses.Mean sedimentation rates from sediment traps were 9.6±2.4 (S.E.) mg cm?2 · day?1 at 10 cm above the bottom and 2.5±0.9 (S.E.) and 2.6±1.2 (S.E.) mg cm?2 · day?1 for two sets of traps at 50 cm above the bottom. Sediment application experiments indicated A. palmata was the least tolerant of the species tested. Although A. cervicornis and D. strigosa colonies were not significantly affected, single applications of 800 mg cm?2 to M. annularis colonies and of 200 mg cm?2 to A. palmata colonies caused death of underlying coral tissue. Algae colonized the smothered portions of these corals.  相似文献   

20.
黄河干流浮游植物群落特征及其对水质的指示作用   总被引：1，自引：0，他引：1  
2008年5-6月和9-10月对黄河干流13个河段和4座水库的浮游植物群落及其环境进行了全面调查.共鉴定浮游植物8门83属150种,其中有硅藻59种,绿藻55种,蓝藻24种,甲藻4种,裸藻4种,金藻2种,黄藻1种和隐藻1种,平均细胞密度和生物量分别为126.90×104cells/L和0.940mg/L.从大的格局上看,浮游植物群落在种类数、种类组成和现存量上均存在较明显的空间分异,这种分异性可从河流流速、泥沙含量和受污染程度得到解释.根据浮游植物污染指示种和Shannon-Wiener多样性指数分析,黄河干流各河段多受到不同程度的污染.与1986年的资料相比,黄河干流浮游植物组成发生了明显变化,属数下降了9.8%,而平均生物量升高了128.7%,且在种类组成上也发生了明显的变化,表明河流污染程度的加剧.  相似文献   

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