Biochemical parameters of plants as indicators of air pollution

In the present study species like Mangifera indica, Linn., Cassia fistula, Linn., and Eucalyptus hybrid were exposed to different air pollution load for short duration (active biomonitoring). Variation in biochemical parameters like chlorophyll, protein, soluble sugar free amino acid, ascorbic acid, nitrate reductase, superoxide dismutase and peroxidase in the leaves were found to be pollution load dependent. These variations can be used as indicators of air pollution for early diagnosis of stress or as a marker for physiological damage to trees prior to the onset of visible injury symptoms. Just by analyzing these biochemical indicators air quality can also be assessed.     

Fresh water fishes as indicators of Kaveri River pollution

The survey of fish fauna in Kaveri River at polluted and unpolluted sites revealed a direct effect on the distribution of fishes in that 14 species were observed in unpolluted site and only 6 species in polluted site. Further, the haemotological parameters like RBC, WBC and haemoglobin content increased in fishes collected from polluted site whereas the organic constituents of muscle decreased in the above fishes when compared to the fishes of unpolluted site. The reason for the above changes is discussed.     

Ostracods as indicators of pollution in the lakes of Mysore

Ostracods are small crustaceans found in aquatic habitats and the present paper deals with the role of water quality index on their population diversity and seasonal fluctuations in the four lakes of Mysore city The present investigation was carried out from July 2004 to June 2005. The study revealed highest water quality index and population density of ostracods during summer and least during winter Dalvoi lake recorded higher waterquality index (125.04), population density (60 l(-1)) but lower species diversity (2 species) of ostracods, whereas Kamana lake recorded lowest water quality index (63.49), population density (40 l(-1)) and highest species diversity (6 species) of ostracods. Increase in the water quality index indicates increase in the pollution load. As water quality index (WQI) increases, population density of ostracods increases but species diversity decreases.     

Limestone surfaces in built-up environment as indicators of atmospheric pollution

The concentration of sulphate on limestone surfaces of the external walls of churches in Malta is shown to be related to their position and distance from a power station, the main local point source of sulphur dioxide pollution. Limestone powder collected from these surfaces was examined for the presence of particles which, under low-power optical microscopy, appear as shiny black amorphous bodies which were interpreted as soot particles; the abundance of these bodies was expressed as a black particle count (BPC). The degree of sulphation and BPC were shown to be correlated with each other and both appeared to be strongly dependent on the prevailing wind. The BPC contour map indicated an important contribution to the parameter from vehicular traffic. It is suggested that the degree of sulphation and BPC of limestone surfaces from the built environment should function as environmental indicators of the relative air quality with respect to SO₂ and soot pollution. This data is possibly more accurately representative of the relative long-term air-quality status of different areas of habitation than that deduced from single or episodic measurements of atmospheric pollutant levels.     

Barnacles: Possible indicators of zinc pollution?

Barnacles [Balanus balanoides (L.), Elminius modestus Darwin, Lepas anatifera (L.)] from several different sites were found to accumulate the heavy metal zinc. The majority of the zinc was deposited in the tissues associated with the gut, and the level of zinc in soft body tissue generally reflected well the level of zinc in the immediate sea-water environment. The zinc accumulated in the gut tissues was in the form of discrete granules, mainly within the parenchyma cells which surround the gut. These granules probably exist as an insoluble zinc salt. A comparison of the zinc level in barnacles with those recorded for some other marine organisms indicates the possible usefulness of barnacles as indicators of zinc pollution.     

Biota as toxic metal indicators

Metal in the environment arises from both natural sources and human activities. Toxic metals in air, soil, and water have become a global problem. They are potential hazards to aquatic, animal, and human life because of their toxicity, bioaccumulative, and non-biodegradable nature. The major impacts of metal pollutants can be stated as ecosystem contamination and health problems of exposed human populations. Those problems have been a cause of increasing public concern throughout the world. Some trace metals are used by living organisms to stabilize protein structures, facilitate electron transfer reactions, and catalyze enzymatic reactions. But even metals that are biologically essential can be harmful to living organisms at high levels of exposure. An increasing concentration of heavy metals in the environment can modify mineral and enzyme functions of human beings. During the last two decades, the interest in using bioindicators as monitoring tools to assess environmental pollution with toxic metals has increased. Bioindicators are flora and fauna members, which are collected and analyzed to measure the levels of metal contaminants. Bioindicators therefore identify health hazards. Various living organisms, such as microbes, fungi, plants, animals, and humans, are used to monitor toxic metals from air, water, sediment, soil, and food chain. Here, we review recent bioindicators, toxicity assessment, and ecological effects.     

Occurrence and seasonal variation of bacterial indicators of faecal pollution along Thoothukudi Coast, Tamil Nadu

Theprevalence and seasonal variation of bacterial indicators of faecal pollution such as total coliform bacteria, faecal coliform bacteria, Escherichia coli and faecal streptococci were investigated in samples of water and beach sand from the four fish landing centres of Thoothukudi. Further the samples were screened for Salmonella to study the reliability of faecal indicator bacteria as an index of human pathogenic bacteria. Total coliform bacteria, faecal coliform bacteria and Escherichia coli were isolated from all four landing centres from undetectable to the maximum detectable level of over Most Probable Number 140 throughout the year with no obvious seasonal variation. Faecal streptococci were also detected in most samples. There was no discernable relationship between faecal indicators and physical parameters. The relationship between faecal indicators and Salmonella was not significant (p > 0.05). The results showed that the coastal waters along Thoothukudi is polluted and presents a potential risk to public for recreational and fishing activities.     

Biomarkers of oxidative stress as indicators of water pollution in Nile tilapia (Oreochromis niloticus) from a water reservoir in Riyadh,Saudi Arabia

Antioxidant enzyme activities of fish (Oreochromis niloticus) were determined in order to assess the status of pollution in the Wadi Namar (WN), near Riyadh, Saudi Arabia. Activities of four antioxidant enzymes as superoxide dismutase (SOD), catalase (CAT), glutathione S-transferase (GST), and concentrations of glutathione (GSH) and oxidant malondialdehyde (MDA) were selected as bioindicators. Fish (n = 14) were sampled in the month of April 2013 from WN and a control site (CS). SOD activity was increased by 37.9%, 47%, and 29% in kidney, liver, and heart, respectively, while a significant decrease (36.4%) was observed in gills of O. niloticus from WN as compared to fish from CS. CAT activity was reduced by 51%, 55%, 47%, and 35% in kidney, liver, heart, and gills of O. niloticus from WN. The GST activities in kidney, liver, and heart of O. niloticus from WN were elevated by 34%, 48%, and 32%, respectively. However, significant fall (49%) in gills of fish was noted from WN compared to fish from CS. GSH levels were increased by 44%, 36%, and 38% in kidney, liver, and heart, respectively, but decreased by 30% in gills. MDA levels of O. niloticus were significantly increased in kidney, liver, and heart in fish from WN. Data indicated that WN is polluted mainly by industrial and urban discharge of liquid waste products.     

Crassostrea virginica as an indicator of lead pollution

After treatment with 1.0 and 3.3 g Pb kg^-1 for 20 weeks in flowing seawater at ambient salinity and temperature, Crassostrea virginica accumulated as much as 6.57 and 11.42 g g^-1 dry weight, respectively, and no mortalities were recorded. Lead uptake was curvilinear; however, the general trend was an increase in lead concentration over time. Dry weight of the oyster had no significant relation with tissue lead concentration (g g^-1); however, a significant positive relationship existed between weight and lead content (g). A decrease in lead concentration in the tissues occurred from mid-August to mid-September despite continuous addition of lead to the seawater. Addition of lead to the seawater was terminated after 20 weeks (October), and lead loss was studied for the following 12 weeks. Lead loss was studied well after spawning in an attempt to eliminate any influence this might have on lead concentration in the tissues. After 4 weeks, approximately 54% of the accumulated lead was lost under conditions of a natural temperature decline. The biological half-life of lead in C. virginica tissues was calculated to be 5.5 weeks. In the ensuing 8 weeks, little or no lead loss was observed. Larvae from each treatment developed to the straight-hinged stage within 48 h with no apparent abnormalities. Lead appeared to have no adverse effect on larvae when parents had been treated with 1.0 and 3.3 g kg^-1 seawater for 10 weeks.     

Crassostrea virginica as an indicator of cadmium pollution

As much as 89, 176 and 292 g Cd g^-1 dry weight were accumulated by adult Crassostrea virginica after treatment for 40 wk with 5, 10 and 15 g Cd kg^-1, respectively, in flowing seawater at ambient salinity and temperature without mortalities. Cadmium accumulation increased with increased concentration of cadmium in seawater; greater amounts were accumulated during the summer months. Uptake patterns measured as cadmium content were similar among the total soft parts, gill, mantle and visceral mass. A continuous increase of cadmium concentration in the visceral mass was observed. This differed from the uptake patterns observed as cadmium concentration in gill, mantle and total soft parts. Although cadmium accumulation in the total soft parts and the tissues was curvilinear over the entire study period, significant linear relations between cadmium concentration and time indicated a general increasing trend. At seawater temperatures below 6°C, when oysters were not actively feeding, cadmium concentrations in the total soft parts varied significantly between treatments, but not within treatments. In the tissues, the rate of uptake expressed as cadmium concentrations was visceral mass>gillmantle. Cadmium concentration in the total soft parts varied inversely with dry weight, whereas cadmium concentration in the total soft parts increased, whereas the content decreased. Cadmium concentration decreased in mantle and gill but increased in the visceral mass during spawning, whereas cadmium content decreased in all tissues. Regression analyses indicated that during spawning dry weight decreased at the same rate in gill and mantle, but they lost less weight and lost it more slowly than visceral mass. Also, during spawning, cadmium content decreased in mantle and gill at the same rate but more slowly than in the visceral mass. In mid-August, Cd concentration decreased despite the continuous addition of cadmium to the seawater; however, Cd content increased, suggesting that organism weight was responsible for fluctuations in cadmium concentrations.     

Rapana venosa as a bioindicator of environmental pollution

The aim of this investigation was to examine biochemical differences in the gastropod Rapana venosa (R. venosa) from polluted (RvP) and nonpolluted (RvN) sites of the Black Sea's Bulgarian coast that may serve as bioindicators of environmental quality. Mussels Mytilus galloprovincialis (MMg) were collected from polluted (MMgP) and nonpolluted (MMgN) sites at the same time for comparison. Bioactive compounds and the antioxidant activity of dry matter (DM) methanol extracts from RvP and RvN were determined. Three-dimensional fluorometry (3D-FL) and Fourier transform infrared (FTIR) analyses were used to evaluate polyphenols and proteins. DM methanol extracts from RvP, and to lesser extent RvN, showed high amounts of total phenolics (23.22±2.9 and 15.60±1.8 mg GAE · g^?1 DW) and exhibited high levels of antioxidant activity in some radical scavenging assays (μ MTE · g^?1 DW): 56.38±5.2 and 33.79±3.3 by 2,2azino-bis (3-ethyl-benzothiazoline-6-sulfonic acid) diamonium salt (ABTS·⁺); 54.79±5.6 and 33.7±2.6 by cupric reducing antioxidant capacity (CUPRAC); 62.34±6.8 and 30.31±3.9 by the 1diphenyl-2-picrylhydrazyl method (DPPH). A correlation in the above indices was found between R. venosa and M. galloprovincialis, but all results were relatively higher for M. galloprovincialis than for R. venosa. The obtained indices of R. venosa may serve as a bioindicator of environmental ecological quality.     

Biological benthic tools as indicators of coastal marine ecosystems health

Coastal marine ecosystems are increasingly subjected to environmental stress and degradation due to pollution. Several research programmes have addressed this problem and produced relevant data sets for specific areas, often including consistent sets of environmental and biological variables. The value of existing information gathered from these types of data can be largely increased by combining them into a common data set to determine globally applicable relationships. To perform this exercise, the Intergovernmental Oceanographic Commission (IOC) of UNESCO has recently formed the Ad hoc Study Group on Benthic Indicators (http://www.ioc.unesco.org/benthicindicators) with the aim of developing robust indicators of benthic health. In this paper, initial products and ongoing activities of this international initiative are described and discussed. An expansion of initial IOC/UNESCO research on benthic fauna-organic carbon relationships is also presented. As part of this follow-up research, the relationship between total organic carbon concentrations of sediment and abundance, biomass and species diversity of benthic macrofauna was evaluated using data sets from 2 different regions of the world comprising 3 different coastal marine environments. The ability of identifying threshold levels in selected variables that could serve as indicators of related adverse environmental conditions leading to stress in the benthos is envisaged within the frame of a larger joint analysis, carried out by the IOC/UNESCO Study Group on Benthic Indicators, of merged data sets from several coastal regions worldwide.     

F-RNA噬菌体及其作为水中肠道病毒指示物的研究进展

城市污水的再生利用是缓解水资源紧张、减少水污染和改善生态环境的有效途径。污水及其回用水中的肠道病毒对人体健康的风险日益受到关注。直接检测水中肠道病毒的操作复杂、安全性差、时间长、需要专门的技术和设备，因此需要寻找合适的指示生物，以实现对水中肠道病毒的及时检测和风险评价。F-RNA噬菌体是通过性菌毛感染雄性大肠杆菌的一类RNA细菌病毒，在污水中普遍存在，在大小、形态结构及对环境条件和水处理过程的抗性与肠道病毒相似，被认为是水中肠道病毒的合适的指示生物。文章介绍了F-RNA噬菌体在环境及污水中的分布、存活和去除特性、检测方法及作为水中肠道病毒指示生物的研究进展。     

Microbial diversity and ecological networks as indicators of environmental quality

Evaluating the quality of ecosystems in terms of biological patrimony and functioning is of critical importance in the actual context of intensified human activities. Microbial diversity is commonly used as a bioindicator of ecosystems functioning. However, there is a lack of sensitivity of microbial diversity indicators in the case of moderate and chronic environmental degradation, such as atmospheric deposition of pollutants, agricultural practices, diffuse pollution by wastewater and climate change. As a consequence, there is a need for alternative bioindicators of soils and water quality. Here, we discuss the interest of adopting a more integrative approach based on biotic interaction networks beyond the simple diversity indicators. We review how the various biotic interactions can be integrated in the various microbial networks such as trophic, mutualistic and co-occurrence networks. Then we discuss the efficiency of microbial networks and associated metrics to detect changes in microbial communities. We conclude that the connectance, the number of links and the average degree of co-occurrence networks could vary from 10 to 50% in response to minor perturbations when microbial diversity parameters remain stable. Finally, we analyze studies that aimed at linking microbial networks and activity to evaluate the potential of such networks for providing simple and operational indicators of ecosystem quality and functioning.     

Biological benthic tools as indicators of coastal marine ecosystems health

Coastal marine ecosystems are increasingly subjected to environmental stress and degradation due to pollution. Several research programmes have addressed this problem and produced relevant data sets for specific areas, often including consistent sets of environmental and biological variables. The value of existing information gathered from these types of data can be largely increased by combining them into a common data set to determine globally applicable relationships. To perform this exercise, the Intergovernmental Oceanographic Commission (IOC) of UNESCO has recently formed the Ad hoc Study Group on Benthic Indicators (http://www.ioc.unesco.org/benthicindicators) with the aim of developing robust indicators of benthic health. In this paper, initial products and ongoing activities of this international initiative are described and discussed. An expansion of initial IOC/UNESCO research on benthic fauna-organic carbon relationships is also presented. As part of this follow-up research, the relationship between total organic carbon concentrations of sediment and abundance, biomass and species diversity of benthic macrofauna was evaluated using data sets from 2 different regions of the world comprising 3 different coastal marine environments. The ability of identifying threshold levels in selected variables that could serve as indicators of related adverse environmental conditions leading to stress in the benthos is envisaged within the frame of a larger joint analysis, carried out by the IOC/UNESCO Study Group on Benthic Indicators, of merged data sets from several coastal regions worldwide.     

Robustness of variance and autocorrelation as indicators of critical slowing down

Ecosystems close to a critical threshold lose resilience, in the sense that perturbations can more easily push them into an alternative state. Recently, it has been proposed that such loss of resilience may be detected from elevated autocorrelation and variance in the fluctuations of the state of an ecosystem due to critical slowing down; the underlying generic phenomenon that occurs at critical thresholds. Here we explore the robustness of autocorrelation and variance as indicators of imminent critical transitions. We show both analytically and in simulations that variance may sometimes decrease close to a transition. This can happen when environmental factors fluctuate stochastically and the ecosystem becomes less sensitive to these factors near the threshold, or when critical slowing down reduces the ecosystem's capacity to follow high-frequency fluctuations in the environment. In addition, when available data is limited, variance can be systematically underestimated due to the prevalence of low frequencies close to a transition. By contrast, autocorrelation always increases toward critical transitions in our analyses. To exemplify this point, we provide cases of rising autocorrelation and increasing or decreasing variance in time series prior to past climate transitions.     

溪流底栖动物定量与半定量采样法比较研究

溪流底栖动物定量和半定量采样法在个体数、物种数、物种相似性及生物指数方面的比较研究表明:(1)急流生境中,半定量样(踢网)的个体和物种数高于定量样(索伯网);静水-缓流生境中,半定量样(D形网)的个体和物种数一般高于定量样,且物种数有显著差异(z=-2.032,P<0.05).(2)同一样点半定量样(踢网加D形网)与定量样之间的物种相似性(平均为0.68)高于急流生境(0.56)和静水-缓流生境(0.45).(3)同一样点半定量样和定量样单独计算的生物指数值之间无显著差异.建议在应用溪流底栖动物开展水质生物评价时,可用半定量采样法完成野外采样.图4表1参8     

Macroinvertebrates As Bioindicators of Water Pollution in Streams Draining Dairy Farming Catchments

Runoff from intensive dairy farming systems can impair the quality of catchment waters, with potential ecological and human health implications. A water quality study was carried out in three streams in a predominantly dairy farming region, with the aim of assessing the effects of diffused- and point-sourced inputs on a number of water quality parameters and benthic macroinvertebrates. the results showed significant increases in streamwater biochemical oxygen demand (BOD), ammonium-nitrogen (NH₄-N) and molybdate reactive phosphorus (MRP) concentrations between the farm reaches. These changes in water quality appeared to be due largely to the point-sourced inputs from farmyards, and had a significant effect on the ability of the water to support a healthy and diverse community of invertebrates. the results also showed that concentrations of dissolved oxygen (DO) and ammonium in streamwater were the two most important parameters studied that were inversely related to the invertebrate scores.     

Evaluation of information indices as indicators of environmental stress in terrestrial soils

Information indices from Ecosystem Network Analysis (ENA) can be used to quantify the development of an ecosystem in terms of its size and organization. There are two types of indices, i.e. absolute indices that describe both the size and organization of ecosystem (Total System Throughput (TST)—system size, Ascendancy (A)—size of organized flows and Development Capacity (C)—upper limit for A, Overhead (L)—size of unorganized flows) and relative indices that describe only the organization (Average Mutual Information (AMI = A:TST), Flow Diversity (H = C:TST), Relative Overhead (RL = L:TST)).It is theorized that environmental stress impair the ecosystem development and that the effect of stress can be quantified with the ENA information indices. Here we applied ENA on a case of environmental stress in a terrestrial ecosystem, i.e. soils that have endured long-term exposure to elevated copper concentration and altered pH.The absolute indices showed an unexpected pattern of response to pollution, suggesting that ecosystems in polluted soils are more active and better organized than these in unpolluted soils. The relative indices, alternatively, responded to pollution as predicted by theory, i.e. with decrease of stress (pollution level) the level of specialization increased (increase of AMI) and losses of energy, e.g. due to respiration, decreased (decrease of Overhead). The diversity and evenness of flows showed hump-backed relationship with stress. Less polluted soils appeared to be less vulnerable to external disturbances and more efficient in processing energy (higher Relative Ascendancy (RA = A:C)) than polluted soils. The relative information indices were rigid to changes in values of assumed parameters. The relative indices, opposite to absolute indices, appeared to be useful as indicators of environmental stress on the ecosystem level.