Indicators Of Environmental Conditions Research Articles

Chemical and toxicological studies on black crust formed over historical monuments as a probable health hazard

Studies to date have mostly investigated environmental factors responsible for deterioration of historical monuments. Black crusts formed on historical monuments are considered as factor for deterioration of structures or as an indicator of environmental status of the surrounding area. Black crust formed on historical monuments has never been investigated as a health hazard. Herein, for the first time, we performed in vitro and in vivo toxicology studies of black crust formed on three culturally-rich historical monuments (Rang Ghar, Kareng Ghar, and Talatal Ghar) of the Indian subcontinent to test their toxicological effect. Black crust suspension in ultrapure water was found not to be considerably toxic to the cells upon direct short-term exposure. However, the sub-acute nasal exposure of the black crust suspension in Swiss albino mice produced lung-specific pathologies and mortality. Additionally, structural formation of the black crust along with the speciation of potentially hazardous elements (PHEs), polyaromatic hydrocarbon (PAHs), and other metals were investigated. Overall, these results indicate the potential of black crust deposited on historical monuments as health hazard owing to the atmospheric pollution of the surroundings. However, it may be noted that black crust and its components have very low possibility of health implication unless they are disturbed without proper care.

Effects of biological and environmental factors on the variability of Paralonchurus brasiliensis (Sciaenidae) density: An GAMLSS application

The hypothesis of this study was based on the premise that complex interactions between biological and environmental factors may explain variability in fish population dynamics. To test this, Paralonchurus brasiliensis (Sciaenidae), a keystone species associated with coastal waters, was used as a model fish species. Generalized Additive Models for Location, Scale and Shape were performed to evaluate relationships among biological and environmental variables. Fish biomass, repletion index (RI), hepatosomatic index (HSI), condition factor (K) and sex ratio was in models as biological factors whereas water temperature, salinity, organic matter, grain size and depth were included as environmental variables. The results revealed significant effects of biological and abiotic factors on population density of P. brasiliensis. The selected model explained 94% of the variability in the explanatory variables. Fish biomass, HSI and K were the most important biological factors, whereas temperature and organic matter were the most important abiotic factors. Variability in fish density suggests that HSI and K both could be used as an additional ecosystem indicator of environmental status (food availability) and fish population health. We also highlight the importance of using robust and flexible statistical methods to model fish population dynamics and the need to incorporate biological and environmental factors into fishery resource management.

Waste Management to Improve the Condition in Kerman Graduate University of Technology

Background: Green management is a significant factor in the sustainable development and improvement of organizational performance levels. Therefore, the development of university waste management with a green management approach can improve university sustainability indicators of environmental status and quality. This study aims to evaluate the Kerman Graduate University of Technology (KGUT) status of waste management. Methods: In this study, using field visits, checklists, and interviews with managers and service personnel, the status of waste management in different KGUT buildings was investigated. A sampling of university waste was performed, and then the storage status of special wastes and tanks was examined. Finally, we tried to suggest solutions to improve the status of the waste management system. Results: In this study, using the analytical hierarchy process, the indicators were prioritized. Also, sampling and physical analysis of university waste was performed, and the amount of waste production was compared with other universities. Twenty-one indicators impacting KGUT waste management were discussed and prioritized in three categories of educational, executive, and managerial measures. The per capita production of ordinary waste in the University was found to be 233.5 g/d, an average amount comparable to other universities. Conclusion: The management of hazardous waste in the University needs attention, and improving the storage system and its disposal is the priority of corrective measures. An important step is training staff and students in waste management, which can pave the way for many changes.

Relative body condition of red mullet (Mullus barbatus) and its applicability as an indicator of environmental status

This study examines the ratio between length and body weight of 4191 specimens of a prevalent, tertiary tropic level Teleost fish, red mullet (Mullus barbatus) sampled using a standard survey protocol from more than 2500 km by the coasts of Turkey extending along the Mediterranean, Aegean, and the Black Sea. The study’s primary aim was to investigate whether there is a correspondence between the body condition of the red mullet and the environmental status independently determined based on lower trophic levels of the water masses the species inhabits. Possible impacts of some intrinsic (fish length), extrinsic factors (bathymetry, abundance, and site), and numerical condition expressions on the outcomes were analyzed and eliminated. The results displayed a strong positive correlation between the fish condition index values and the ecosystem descriptor; the body condition of fish increased as ecological status improved from ”bad” to ”good/high”. Based on this relationship and to facilitate the use of red mullet body condition as an ecosystem indicator, a set of target reference values addressing different ecological states have been proposed.

Bacterioplankton composition as an indicator of environmental status: proof of principle using indicator value analysis of estuarine communities

Increasing awareness of environmental impacts caused by anthropogenic activities highlights the need to determine indicators of environmental status that can be routinely assessed at large spatial and temporal scales. Microbial communities comprise the greatest share of biological diversity on Earth and can rapidly reflect recent environmental changes while providing a record of past events. However, they have rarely been targeted in the search for ecological indicators of habitat types, environmental conditions, or environmental changes. Here, as a proof of principle, we analysed the bacterioplankton community composition of 4 estuaries in North and South America, Europe, and Asia, and looked for indicators of groups of samples defined using partition techniques, according to primary physicochemical variables typically monitored to infer water quality. Indicator value analysis (IndVal) was conducted to identify indicator operational taxonomic units (OTUs; analogous to species in other fields of ecology) in each group. These bacterioplankton-based indicators exhibited a high capacity to predict the group membership of the samples within each estuary and to correctly assign the samples to the appropriate estuary in a combined data set, employing different machine learning techniques. The indicators were composed of OTUs belonging to several bacterial phyla, which responded significantly and differentially to the environmental variables used to define the groups of samples. Moreover, the predictive values of these bacterial indicators were generally higher than those of other biological assemblages commonly used for environmental monitoring. Therefore, this approach appears to be a promising tool to complement existing strategies for monitoring and conservation of aquatic systems worldwide.

Body volume in ground beetles (Carabidae) reflects biotope disturbance

Abstract Changes in body size of living organisms can indicate changes in environmental quality. The family Carabidae is frequently used as an indicator of environmental status. We collected ground beetles in 9 Slovakian localities (in the Veporské vrchy Mts and the Juhoslovenská kotlina Basin) of various levels of disturbance, and evaluated the volume of individuals. The lowest average body volumes of individual were found for an intensively grazed pasture (locality 5) and a nitrophilous waterside vegetation (locality 6) (1,298 mm3–4,648 mm3) with predominantly macropterous species. We have confirmed the significantly higher average biovolume value of individual Carabidae in less disturbed habitats: a Picea abies plantation (locality 1), a Carpathian oak-hornbeam forest (locality 4) and a Carpathian turkey oak forest (locality 7) (from 9,837 mm3 to 13,038 mm3), where apterous and brachypterous species dominated.

Evaluation of a national food industry based on environmental performance and condition indicators: critical success and barriers of EMS implementation in Tunisia

This paper attempts to assess environmental performance indicators (EPIs) of Tunisian food industry as well as the effectiveness of its environmental management system (EMS) according to the ISO 14001 standard. It is related to the management effort which is measured by management performance indicators and to organization’s operations representing the operational performance indicators in order to reduce the significance of environmental impacts. Otherwise, it does reflect critical success and barriers of environmental performance of a food company for its management and operation processes according to the Tunisian context. Moreover, this research focuses on environmental condition indicators (ECIs) in developing of environmental performance evaluation (EPE). EPIs and ECIs depend closely on the compliance of the food company with applicable laws and regulatory requirements that stimulate the pollution prevention. Furthermore, EPE integrates environmental and human health risks in assessment process consequently ensuring the adoption of a new policy by decision makers under the concept of continuous improvement. However, it should discuss a voluntary initiative taking by the top managers to prevent pollution and to share information in a structured and regular way.

Implementing and Innovating Marine Monitoring Approaches for Assessing Marine Environmental Status

Marine environmental monitoring has tended to focus on site-specific methods of investigation. These traditional methods have low spatial and temporal resolution and are relatively labor intensive per unit area/time that they cover. To implement the Marine Strategy Framework Directive (MSFD), European Member States are required to improve marine monitoring and design monitoring networks. This can be achieved by developing and testing innovative and cost-effective monitoring systems, as well as indicators of environmental status. Here, we present several recently developed methodologies and technologies to improve marine biodiversity indicators and monitoring methods. The innovative tools are discussed concerning the technologies presently utilized as well as the advantages and disadvantages of their use in routine monitoring. In particular, the present analysis focuses on: (i) molecular approaches, including microarray, Real Time quantitative PCR (qPCR), and metagenetic (metabarcoding) tools; (ii) optical (remote) sensing and acoustic methods; and (iii) in situ monitoring instruments. We also discuss their applications in marine monitoring within the MSFD through the analysis of case studies in order to evaluate their potential utilization in future routine marine monitoring. We show that these recently-developed technologies can present clear advantages in accuracy, efficiency and cost.

Cover of coastal vegetation as an indicator of eutrophication along environmental gradients.

Coastal vegetation communities are important for primary production, biodiversity, coastal protection, carbon and nutrient cycling which, in combination with their sensitivity to eutrophication, render them potential indicators of environmental status for environmental policies like the EU Water and Marine Strategy Framework Directives. We evaluated one potential indicator for coastal vegetation, the cumulative cover at depths where the vegetation is light limited, by investigating its response to eutrophication along gradients in natural conditions. We used a large data set covering the Swedish coastline, spanning broad gradients in nutrient level, water clarity, seabed substrate, physical exposure and climate in addition to a salinity gradient from 0.5 to 30.5. Macroalgal cover increased significantly along gradients of declining nutrient concentration and increasing water clarity when we had accounted for diver effects, spatio-temporal sampling variability, salinity gradients, wave exposure and latitude. The developed empirical model explained 79% of the variation in algal cover across 130 areas. Based on this, we identified macroalgal cover as a promising indicator across the Baltic Sea, Kattegat and Skagerrak. A parallel analysis of soft-substrate macrophytes similarly identified significant increases in cover with decreasing concentrations of total nitrogen and increasing salinity, but the resulting empirical model explained only 52% of the variation in cover, probably due to the spatially more variable nature of soft-substrate vegetation. The identified general responses of vegetation cover to gradients of eutrophication across wide ranges in environmental settings may be useful for monitoring and management of marine vegetation in areas with strong environmental gradients.Electronic supplementary materialThe online version of this article (doi:10.1007/s00227-016-3032-6) contains supplementary material, which is available to authorized users.

Coastal fish indicators response to natural and anthropogenic drivers–variability at temporal and different spatial scales

Ecological indicators are increasingly used in marine and freshwater management but only few are developed towards full operationalization with known patterns of variability and documented responses to natural and anthropogenic environmental drivers. Here, we evaluate potential sources of indicator variability at two different spatial scales in three coastal fish-based indicators of environmental status in the Baltic Sea; abundance of cyprinids, abundance of perch and the proportion of larger perch. The study was performed on a data set covering 41 monitoring areas subject to different levels of anthropogenic impact, at a latitudinal range of 56–66°N and a salinity range of 2–8. Interannual variation was clearly minor relative to spatial variation. Small-scale spatial variation was related to water depth, wave exposure and water temperature. The remaining variation was assessed in relation to differences in natural and anthropogenic drivers between monitoring areas. Cyprinids showed a clear inverse relationship to water transparency, which was used as a proxy for eutrophication, indicating increased abundances in nutrient enriched areas. None of the indicators showed an expected negative relationship to the level of coastal commercial fisheries catches. Rather, a positive relationship for Perch suggested that the coastal fisheries were concentrated to areas with strong perch populations in the studied areas. The effect of salinity and climate (temperature during the growth season) among monitoring areas were small. The results emphasize the importance of assigning area-specific boundary levels to define good environmental status in the coastal fish indicators, in order to account for natural sources of variability. Further, although long-term monitoring in reference areas is crucial for obtaining a historical baseline, our results suggest that the status assessment of coastal fish would generally gain precision by increasingly including spatially based assessments. We propose that similar analytical approaches could be applied to other ecosystem components, especially in naturally heterogenic environments, in order to separate indicator variability attributed to potential anthropogenic impact.

Evaluation of Alternative High-Throughput Sequencing Methodologies for the Monitoring of Marine Picoplanktonic Biodiversity Based on rRNA Gene Amplicons

Sequencing of rRNA gene polymerase chain reaction amplicons (rRNA tags) is the most common approach for investigating microbial diversity. The recent development of high-throughput sequencing (HTS) technologies has enabled the exploration of microbial biodiversity at an unprecedented scale, greatly expanding our knowledge on the microbiomes of marine ecosystems. These approaches provide accurate, fast and cost efficient observations of the marine communities, and thus, may be suitable tools in biodiversity monitoring programs. To reach this goal, consistent and comparable methodologies must be used over time and within sites. Here, we have performed a cross-platform study of the two most common HTS methodologies, i.e. 454-pyrosequencing and Illumina tags to evaluate their usefulness in biodiversity monitoring and assessment of environmental status. Plankton biodiversity has been compared through both methodologies by sequencing the 16S and 18S rRNA genes of a set of samples collected in the coast of Barcelona (NW Mediterranean). The results show that, despite differences observed in the rare OTUs retrieved, both platforms provide a comparable view of the marine picoplankton communities. On a taxonomic level, there was an accurate overlap in the detected phyla between the two methods and the overall estimates of alpha- and betadiversity were comparable. In addition, we explored the concept of ‘indicator species’ and found that certain taxa (i.e. members of the Gammaproteobacteria among others) as well as the ratio between some phylogenetic groups (i.e. the ratio of Alphaproteobacteria / Gammaproteobacteria, Alteromonas / SAR11 and Alteromonas + Oceanospirillales / SAR11) have potential for being useful indicators of environmental status. The data show that implementing new protocols and identifying indicators of environmental status based on rRNA amplicon sequencing is feasible, and that is worth exploring whether the identified indices are universally applicable.

Discovering hidden biodiversity: the use of complementary monitoring of fish diet based on DNA barcoding in freshwater ecosystems.

Ecological monitoring contributes to the understanding of complex ecosystem functions. The diets of fish reflect the surrounding environment and habitats and may, therefore, act as useful integrating indicators of environmental status. It is, however, often difficult to visually identify items in gut contents to species level due to digestion of soft-bodied prey beyond visual recognition, but new tools rendering this possible are now becoming available. We used a molecular approach to determine the species identities of consumed diet items of an introduced generalist feeder, brown trout (Salmo trutta), in 10 Tasmanian lakes and compared the results with those obtained from visual quantification of stomach contents. We obtained 44 unique taxa (OTUs) belonging to five phyla, including seven classes, using the barcode of life approach from cytochrome oxidase I (COI). Compared with visual quantification, DNA analysis showed greater accuracy, yielding a 1.4-fold higher number of OTUs. Rarefaction curve analysis showed saturation of visually inspected taxa, while the curves from the DNA barcode did not saturate. The OTUs with the highest proportions of haplotypes were the families of terrestrial insects Formicidae, Chrysomelidae, and Torbidae and the freshwater Chironomidae. Haplotype occurrence per lake was negatively correlated with lake depth and transparency. Nearly all haplotypes were only found in one fish gut from a single lake. Our results indicate that DNA barcoding of fish diets is a useful and complementary method for discovering hidden biodiversity.

Evolution of the anthropogenic impact in the Augusta Harbor (Eastern Sicily, Italy) in the last decades: benthic foraminifera as indicators of environmental status.

The study of benthic foraminifera in sediment cores provides the opportunity to recognize environmental changes, including those due to the anthropogenic impact. The integration of these data with chemical-physical parameters provides a comprehensive quality assessment. This research was applied to a sediment core collected in the Augusta bay, where a very large commercial and military harbor and one of the largest petrochemical poles in Europe are present. Inside the petrochemical area also operated, from 1958 to 2003, a chlor-alkali plant with mercury cell technology which caused anthropic contamination of surrounding land and marine areas. The sediment core was collected in front of this plant and characterized for grain size and pollutants directly associated to chlor-alkali activity, such as mercury (Hg), barium (Ba), polychlorobiphenyls (PCBs), and polycyclic aromatic hydrocarbons (PAHs). Composition of foraminiferal assemblages and faunal parameters such as specific diversity, faunal density, abundance of abnormal specimens, and foraminiferal size were investigated as potential indicators of environmental status. Statistical analysis indicated a main common origin for Hg, Ba, and PCBs and the influence of pollutants on species distribution and faunal diversity and density. Exceptionally high Hg concentrations (63-680mg/kg d.w.) were recorded in the whole core, where the geochronological study attributed the most contaminated levels to the period of maximum activity of the chlor-alkali plant, while a decrease of contamination was recorded after the stop of the activity. Distinct foraminiferal assemblages identified different ecozones along the core, which suggested decreasing anthropogenic impact from the bottom to the top.

Daily dynamics of photosynthetic parameters in beech population under periodical drought conditions

Abstract The paper presents the impact of periodic soil drought on physiological parameters important for bioproductivity of mountain beech populations. The investigated forest population was located near Fruška gora mountain peak, where water runs off quickly, and consequently lack of soil humidity develops very often. Decreasing trends of photosynthesis, transpiration, water use efficiency and stomatal conductance (gs) during the growing season were evident, in correlation with a shortage of precipitation. Diurnally, photosynthesis of beech leaves showed rhythmical changes. It was the most intensive in the morning, then decreased between noon and 1 pm, and increased again during early afternoon. High leaf temperature and water deficit in the deeper soil layers caused a decreasing trend in photosynthesis and daily rhythmic changes of the transpiration rate and water use efficiency. Although surface soil water capacity did not show a significant decreasing trend from July to September, a lack of precipitation was observed, which probably caused a lack of moisture in deeper soil layers, resulting in a decline in photosynthesis and transpiration. Physiological status, linked to primary photosynthetic productivity of forests, could be a significant indicator of environmental conditions and trends in climate changes.

Industrias de fundición: aspectos ambientales e indicadores de condición ambiental

Nowadays, environmental indicators are widely used as effective tools to assist decision-making in both public and private sectors. The lack of literature and research about local and regional Environmental Condition Indicators (ECI), the poor knowledge regarding solid waste generation, effluents and gas emissions from foundry industries, and their particular location in the urban area of Tandil, Argentina are the main reasons for this investigation, aiming to develop a set a of ECI to provide information about the environment in relation to the foundry industry. The study involves all the foundries located in the city between March and April 2010. The set of ECI developed includes 9 indicators for air, 5 for soil and 1 for water. Specific methodology was used for each indicator.

Diversity of European seagrass indicators: patterns within and across regions

Seagrasses are key components of coastal marine ecosystems and many monitoring programmes worldwide assess seagrass health and apply seagrasses as indicators of environmental status. This study aims at identifying the diversity and characteristics of seagrass indicators in use within and across European ecoregions in order to provide an overview of seagrass monitoring effort in Europe. We identified 49 seagrass indicators used in 42 monitoring programmes and including a total of 51 metrics. The seagrass metrics represented 6 broad categories covering different seagrass organizational levels and spatial scales. The large diversity is particularly striking considering that the pan-European Water Framework Directive sets common demands for the presence and abundance of seagrasses and related disturbance-sensitive species. The diversity of indicators reduces the possibility to provide pan-European overviews of the status of seagrass ecosystems. The diversity can be partially justified by differences in species, differences in habitat conditions and associated communities but also seems to be determined by tradition. Within each European region, we strongly encourage the evaluation of seagrass indicator–pressure responses and quantification of the uncertainty of classification associated to the indicator in order to identify the most effective seagrass indicators for assessing ecological quality of coastal and transitional water bodies.

The FOBIMO (FOraminiferal BIo-MOnitoring) initiative—Towards a standardised protocol for soft-bottom benthic foraminiferal monitoring studies

The European Community Marine Strategy Framework Directive (MSFD) was established to provide guidelines for monitoring the quality of marine ecosystems. Monitoring the status of marine environments is traditionally based on macrofauna surveys, for which standardised methods have been established. Benthic foraminifera are also good indicators of environmental status because of their fast turnover rates, high degree of specialisation, and the preservation of dead assemblages in the fossil record. In spite of the growing interest in foraminiferal bio-monitoring during the last decades, no standardised methodology has been proposed until today. The aim of the FOraminiferal BIo-MOnitoring (FOBIMO) expert workshop, held in June 2011 at Fribourg, Switzerland, which assembled 37 scientists from 24 research groups and 13 countries, was to develop a suite of standard methods. This paper presents the main outcome of the workshop, a list of motivated recommendations with respect to sampling devices, sample storage, treatment, faunal analysis and documentation. Our recommendations fulfil the criteria imposed both by scientific rigour and by the practical limitations of routine studies. Hence, our aim is to standardise methodologies used in bio-monitoring only and not to limit the use of different methods in pure scientific studies. Unless otherwise stated, all recommendations concern living (stained) benthic foraminiferal assemblages. We have chosen to propose two types of recommendations. Mandatory recommendations have to be followed if a study wants to qualify as sound and compatible to the norms. The most important of these recommendations are the interval from 0 to 1 cm below the sediment surface has to be sampled, and an interface corer or box corer that keeps the sediment surface intact is to be used for offshore surveys. A grab sampler must not be deployed in soft sediments. Three replicate samples are to be taken and analysed separately. Samples are to be washed on a 63-μm screen, and the living benthic foraminiferal fauna of the > 125 μm fraction is to be analysed. Splits are to be picked and counted entirely, and all counted foraminifera from at least one replicate per station have to be stored in micropalaeontological slides. Census data, supplementary laboratory data and microslides have to be archived. Advisory recommendations are to sample in autumn, to have a sample size of 50 cm 2 or a tube of 8 cm inner diameter, to use > 70% ethanol as a preservative, rose Bengal at a concentration of 2 grams per litre for staining, and a staining time of at least 14 days. The split size should be defined by a target value of 300 specimens, heavy liquid separation should be avoided, and the 63–125 μm fraction or deeper sediment levels may be considered in some environments. We are convinced that the application of this protocol by a large number of scientists is a necessary first step to a general acceptance of benthic foraminifera as a reliable tool in bio-monitoring studies. ► Benthic foraminifera are proposed for monitoring the quality of marine ecosystems. ► No standardised methodology has been proposed until today. ► The FOBIMO initiative developed a suite of standard methods. ► They concern sampling devices, storage, treatment, faunal analysis and documentation. ► The application will help to establish foraminifera as a tool in bio-monitoring.

Agroenvironmental management system - a technique for increasing the natural value of agroecosystems

Agriculture in the Czech Republic plays an important role in the degradation of individual components of the environment. Reduction of soil fertility, contamination of surface- and groundwater, reduction of biodiversity and damage caused by it are proven. The agrarian landscape does not provide the appropriate ecosystem functions. It is not attractive for life of the inhabitants of rural areas, and the permeable landscape attractive for investors. It is also not permeable and attractive for investors. The farmers are offered applicable and functional techniques, technologies and procedures. These are not used and exploited in an appropriate rate. Based on the analysis of business environment, there was found that the reason is the absence of the agroenvironmental management system in operative management of agricultural subjects. For the need of the possible implementation of the appropriate system into practice, there was developed a branch standard and subsequently a methodology for the application of agro-environmental management system on the basis of a general tool for environmental management. The methodology was developed, then implemented and tested under the conditions of a concrete farm. Before the implementation of requirements, there were established environmental indicators which were evaluated before and after the introduction of the proposed system. The results of the subsequent monitoring of the chosen environmental indicators of environmental status confirmed the functionality and accuracy of the developed management tool that can also be seen as the best available technique for the implementation of the current and prepared agricultural policy.  

Biogeochemical typology and temporal variability of lagoon waters in a coral reef ecosystem subject to terrigeneous and anthropogenic inputs (New Caledonia)

Considering the growing concern about the impact of anthropogenic inputs on coral reefs and coral reef lagoons, surprisingly little attention has been given to the relationship between those inputs and the trophic status of lagoon waters. The present paper describes the distribution of biogeochemical parameters in the coral reef lagoon of New Caledonia where environmental conditions allegedly range from pristine oligotrophic to anthropogenically influenced. The study objectives were to: (i) identify terrigeneous and anthropogenic inputs and propose a typology of lagoon waters, (ii) determine temporal variability of water biogeochemical parameters at time-scales ranging from hours to seasons. Combined ACP-cluster analyses revealed that over the 2000km2 lagoon area around the city of Nouméa, “natural” terrigeneous versus oceanic influences affecting all stations only accounted for less than 20% of the spatial variability whereas 60% of that spatial variability could be attributed to significant eutrophication of a limited number of inshore stations. ACP analysis allowed to unambiguously discriminating between the natural trophic enrichment along the offshore–inshore gradient and anthropogenically induced eutrophication. High temporal variability in dissolved inorganic nutrients concentrations strongly hindered their use as indicators of environmental status. Due to longer turn over time, particulate organic material and more specifically chlorophyll a appeared as more reliable nonconservative tracer of trophic status. Results further provided evidence that ENSO occurrences might temporarily lower the trophic status of the New Caledonia lagoon. It is concluded that, due to such high frequency temporal variability, the use of biogeochemical parameters in environmental surveys require adapted sampling strategies, data management and environmental alert methods.

Mercury in bottom sediments of the Amur River, its flood-plain lakes and estuary, Eastern Siberia

Mercury (Hg) is an element of a special concern in the Amur River basin, where numerous cinnabar deposits and manifestations have been prospected. Moreover, the territory is under heavy anthropogenic pressure due to intensive economic development that includes activities accompanied by noticeable emissions of Hg to the environment through poor waste management practices and accidental emergency discharges. Yet, information on Hg distribution and behavior in this region is scarce and inadequate. In order to evaluate Hg levels and fate in this vast territory, surveys of river, lake, and estuarine bottom sediments, as integral indicators of environmental status, were carried out in 1990, 1991, 1997, and 2004. The results showed the following: (1) stagnation of the Russian economy in the 1990s has resulted in a noticeable decrease of the Hg content in the Amur River sediments to the basin pristine level of about 0.05 mg kg(-1); (2) Hg distribution in the sediment depth proves the element redox-dependent behavior; (3) in some cases, Hg enrichment may be related to the long-term anthropogenic emission; (4) Hg concentration in bottom sediments was found to increase in the following order-the Amur River mouth, the estuary, and the Sea of Okhotsk, showing the weakly non-conservative Hg behavior during estuarine water mixing.