Influence Of Anthropogenic Activities Research Articles

Microbial Communities in Permafrost Soils of Larsemann Hills, Eastern Antarctica: Environmental Controls and Effect of Human Impact.

Although ice-free areas cover only about 0.1% of Antarctica and are characterized by harsh environmental conditions, these regions provide quite diverse conditions for the soil-forming process, having various physical and geochemical properties, and also assuring different conditions for living organisms. This study is aimed to determine existing soil microbial communities, their relationship with soil parameters and the influence of anthropogenic activity in Larsemann Hills, Eastern Antarctica. The soil microbiome was investigated at different locations using 16S rRNA gene pyrosequencing. The taxonomic analysis of the soil microbiomes revealed 12 predominant bacterial and archaeal phyla—Proteobacteria, Actinobacteria, Acidobacteria, Chloroflexi, Gemmatimonadetes, Verrucomicrobia, Planctomycetes, Bacteroidetes, Armatimonadetes, Firmicutes, Cyanobacteria, Thaumarchaeota. Some specific phyla have been also found in sub-surface horizons of soils investigated, thus providing additional evidence of the crucial role of gravel pavement in saving the favorable conditions for both soil and microbiome development. Moreover, our study also revealed that some bacterial species might be introduced into Antarctic soils by human activities. We also assessed the effect of different soil parameters on microbial community in the harsh environmental conditions of Eastern Antarctica. pH, carbon and nitrogen, as well as fine earth content, were revealed as the most accurate predictors of soil bacterial community composition.

Assessment of groundwater quality based on GIS and geochemical methods: coastal aquifer of Bouficha (North-Eastern Tunisia)

In Tunisia, Groundwater is an important water source for domestic, agricultural and industrial uses, but the deterioration of its quality, under the influence of anthropogenic activities and natural factors, limits its suitability for human consumption and irrigation. The present study was carried out to assess groundwater quality in Bouficha aquifer in north-eastern Tunisia using geochemical, geospatial and statistical techniques. The relationship between groundwater quality and Land Use Land Cover (LULC) patterns were also explored using remote sensing, geographic information system (GIS) and Landsat satellite images. Groundwater samples were collected from sixteen wells in April 2015 and analyzed for their physical and chemical characteristics. Concentrations of major cations and anions in the groundwater vary spatially. The dominant water types in the investigation area are Na-Cl and Ca–SO4. A basic statistical study, applying hierarchical classification analysis confirms the existence of two groundwater types. To evaluate the suitability of groundwater for irrigation, chemical data were assessed using methods such as Electrical Conductivity, Kelley’s ratio, Sodium Absorption Ratio, Magnesium Hazards, as well as Residual Sodium Carbonate. Regarding drinking groundwater assessment, the World Health Organization (WHO) standards were applied to define sites with drinking water permissible levels. Information was loaded in an ArcGIS software and analyzed with a Spatial Analyst extension using Inverse Spline interpolation methods. Fluoride content in most samples has values as high as 1.97 mg/L, with 53% of the samples showing fluoride concentration higher than the level suggested by the WHO for drinking water of 1.5 mg/L and ratified by the National Society of Exploitation and Drinking Potable Water of Tunisia. Additionally, reported nitrate concentrations are higher than the expected groundwater background level of 10 mg/L; indeed, values are up to 286 mg/L, being hazardous for domestic use and suggesting the presence of anthropogenic sources of water contamination. The Land Use and Land Cover (LULCC) of Bouficha aquifer were changed over seventeen years. The Landsat satellite images have shown that the built-up area increased from 2001 to 2018 to the detriment of water and crop vegetation. The overuse of fertilizers on a total agricultural area of Bouficha aquifer (60%) led to significant pollutants, including nitrate and a deterioration in its water quality. Regarding the WHO and the Tunisian drinking water guidelines, this work provides substantial evidence that groundwater quality is posing a significant health threat for residents. Similarly, results show groundwater’s chemical content is also unsuitable for economic activities in the Bouficha region, mainly hazardous for irrigation purposes.

Information Technology in Ethnological Examination of Investment Projects of Arctic Development

We examine the methodological and practical issues related to the application of information technologies and space-based monitoring in ethnological examination of projects of Arctic industrial development. The necessity and prospects of using these technologies to assess the resource productivity of the territory are illustrated by the example of the project of the extraction of alluvial gold in the basin of the Mokrundya stream of the Srednekolymskii ulus (district) of the Sakha (Yakutia) Republic. In particular, this is necessary for analyzing the distribution of dominant plant communities, determining the phytomass of pasture plants, stocks of wild plants, and reindeer grazing capacity, and for calculating the losses of the indigenous peoples of the North in the influence zone of the project. A geobotanical map of the study area is provided. It is also shown that the use of space-based monitoring in carrying out an ethnological examination of projects and determining the damage caused to the local population as a result of the impact on traditional land use practices (hunting, gathering wild plants, and reindeer husbandry) makes it possible to take an inventory of pasture lands of reindeer husbandry and reduce the cost of these projects in comparison with traditional methods (field surveys of the territory, and aerial imaging surveys). The possibilities of comparing interannual images can also provide insight into the dynamics of changes in the territory under the influence of anthropogenic activity and taking into account climatic transformations.

Nitrate contamination of groundwater in Ambohidrapeto\u2013Antananarivo-Madagascar using hydrochemistry and multivariate analysis

Nitrate contamination of groundwater was assessed in the crowded area of Ambohidrapeto, Antananarivo city-Madagascar using hydrochemistry and multivariate analysis. Seventeen dug well waters and three spring waters were collected and measured in the field for physical parameters and in the laboratory for major ions. The results showed that all water samples have nitrate concentration above the standard value of 50 mg/L-NO3 set by the World Health Organization, with a minimum value of 79.3 mg/L-NO3 and a maximum value of 394.5 mg/L-NO3. Anthropogenic activities, from the surrounding pit latrines are the main sources of the groundwater nitrate contamination and are dominant over natural processes, which contribute to a lower degree to the groundwater mineralization. Ionic ratios indicated the occurrence of mineral dissolution and silicate weathering as the natural sources of magnesium and sodium, respectively. Furthermore, the correlation between calcium and sodium as well as the Piper diagram revealed the occurrence of ion exchange, resulting in sodium being the dominant cation over calcium. Forty percent (40%) of the water samples have the hydrochemical facies Na–Mg–Cl, followed by Na–Mg–Ca–Cl facies for 25% and Na–Mg–Cl–HCO3 facies for 20%. By applying principal component analysis, the influence of anthropogenic activities is confirmed. The first principal component extracted, which explained 52.88% of the total variance showed strong positive loadings on TDS, NO3−, Cl−, Mg2+, Na+, K+ and Ca2+, indicating that these ions contribute as anthropogenic sources, although Mg2+, Na+, K+ and Ca2+ contribute to a lesser extent than NO3−, and Cl−.

Selected antibiotics and current-use pesticides in riverine runoff of an urbanized river system in association with anthropogenic stresses

Antibiotics and current-use pesticides are ubiquitous in the environment. It is important to figure out their spatial distribution under the influences of anthropogenic activities and transport from rivers to coastal oceans. To address this knowledge gap, the present study conducted quarterly sampling in eight main runoff outlets of the Pearl River, South China, and obtained total concentrations of antibiotics and current-use pesticides at 24–296 ng L−1. Higher total concentrations of these chemicals occurred in summer, attributed to seasonal consumption patterns and washout by rainfalls, respectively. The spatial distributions of target analytes were not significantly different between the eastern and western outlets with high and moderate urbanization levels, respectively. Approximately 16.4, 17.7, and 12.5 tons of antibiotics, organophosphorus pesticides, and neonicotinoids were discharged annually from the outlets to the South China Sea. These results suggested that usage amount and hydrology exhibited positive effects on the riverine inputs of the target chemicals. In addition, most target chemicals exhibited low risks to green algae, but erythromycin and parathion posed high ecological risks to aquatic organism (Daphnid and fish).

Modeling cetacean habitat use in an urban coastal area in southeastern Brazil

Most studies of cetacean habitat use do not consider the influence of anthropogenic activities. We investigated the influence of environmental and anthropogenic variables on habitat use by humpback Megaptera novaeangliae and Bryde’s whales Balaenoptera brydei off the coast of the Brazilian city of Rio de Janeiro. Although there are 2 marine protected areas (MPAs) in this area, few data are available on cetacean habitat use or on the overlap of different cetacean species within these MPAs. Our aim was to evaluate the effectiveness of the MPAs and propose a buffer zone to better protect the biodiversity of the study area. We conducted systematic surveys and developed spatial eigenvector generalized linear models to characterize habitat use by the species in the study area. Habitat use by humpback whales was influenced only by depth, whereas for Bryde’s whales there was the additional influence of anthropogenic variables. For Bryde’s whales, which use the area for feeding, sea surface temperature and the distance to anchorages had a major influence on habitat use. We also showed that neither of the MPAs in the study area adequately protects the hotspots of either whale species. Most of the humpback whale grid cells with high sighting predictions were located within 2 km of the MPAs, while areas of high sighting prediction of Bryde’s whales were located up to 5 km from the MPAs, closer to beaches. Our findings provide important insights for the delimitation of protected areas and zoning of the MPAs.

Natural and anthropogenic dispersal of cyanobacteria: a review

Cyanobacteria are oxygenic photosynthetic organisms that are prevalent in freshwater and marine ecosystems. A proportion of the cyanobacteria in a given locality are known to be introduced from other regions and are able to cause harmful cyanobacterial blooms. However, the processes by which cyanobacteria is relocated are not well described. This review presents the various natural and anthropogenic methods of cyanobacterial transport, with emphasis on the dispersal of problematic taxa. Natural mechanisms for transport of cyanobacteria include meteorological phenomena such as dust storms and tsunamis, which facilitate the long-distance transport of cyanobacteria through the air and rafting debris in oceans, respectively. Cyanobacteria can also be transported by animals such as worms, seabirds and planktivorous fish. The influence of anthropogenic activities on cyanobacterial distributions is also discussed, with focus on transport through international shipping and on rafting surfaces provided by plastic pollution. In this study, a total of 150 species of cyanobacteria from 64 genera were identified to be transported across a combination of natural and anthropogenic methods. As cyanobacteria are organisms that are prevalent in many ecosystems, an understanding of these transport processes will allow for improved assessment and monitoring of introduced toxic cyanobacterial species.

Effects of anthropogenic disturbance on the species assemblages of birds in the back mangrove forests

Around the world, mangrove ecosystem has faced major threats from human activities, and birds were unexceptionally impacted. Mangrove fringe a large extent of the east and west coast of Peninsular Malaysia. The intertidal gradients along the coastline, has formed a brackish zone (back-mangrove), which exhibited different pattern of mangrove species, but received much less attention. In this study, we compare species assemblages of birds based on different level of anthropogenic pressures at different back-mangroves sites; KY; KD and KST which is measured by analysis of land use change for 15 years using ERDAS Imagine. 97 species from 36 families of birds were recorded from all sites, dominated by family Alcedinidae (kingfishers), Ardeidae (egrets, herons) and Coraciidae (dollarbirds). Anthropogenic disturbance changes the landscape structure, with reduction of mangrove cover, other than increasing horticulture, urbanization, and monoculture plantation activities. This is most apparent at KY, followed by KD and lowest at KST, which also showed reducing in species abundance and richness of birds. Species assemblages of birds also differ, as highly disturbed sites exhibited a poorer representation of mangroves-specialist, compared to less disturbed sites as illustrated by the nMDS ordination. Finally, PERMANOVA analysis showed significant effect of the bird family and their ecological niches towards the species assemblages at different back-mangrove sites. The high abundance of open country species such as mynas, crows and doves at all sites indicate the influence of anthropogenic activities. Presence of several highly protected species indicates high conservation value of the back-mangrove zone, apart from their true-mangrove counterparts.

Hydrogeochemical Characterization and Assessment of Contamination by Inorganic and Organic Matter in the Groundwater of a Volcano-Sedimentary Aquifer.

The chemical composition of groundwater is a product of the evolution and transformation of major ions, which come from natural hydrogeochemical processes or from anthropogenic interference. The objective of this study was to identify the hydrogeochemical processes and the influence of anthropogenic activity on the variation of chemical composition in Toluca Valley groundwater. The type of water in the zone is fundamentally Mg-Ca-HCO3. Three groups with different evolutionary tendencies were identified: one within a local recharge zone and two others in an intermediate region with anthropic activity. The latter, which show contamination by inorganic matter (fertilizers) and organic matter (urban or industrial wastewater). The content of N-NO3- (0.024-0.219 mEqL-1), N-NH4+ (0-0.022 mEqL-1), Porg (0.03-1.02mEqL-1) and PO43- (0.0-0.28 mEqL-1) indicated contamination coming from inorganic and organic matter. These chemical compounds were identified by way of a 3D fluorescence technique. The results of this study demonstrate that the main processes that affect and control the chemical composition of the water in the Toluca Valley aquifer are weathering of silicates, the ion exchange and a mixture process generated by a source of anthropic contamination.

Effects of human disturbance and altitudinal gradient on myriapod species richness and abundance at Mount Kala, central Cameroon

Myriapods are remarkably diverse and encompass many endemic species, yet they remain poorly studied in Cameroon. We investigated the influence of anthropogenic activities on myriapod assemblage structures along an altitudinal gradient at Mount Kala. Myriapods were collected by pitfall trapping, hand sorting and litter sifting in four altitudinal levels and habitats (820 m, 920 m, 1 020 m and 1 120 m above sea level) from November 2017 to July 2018. A total of 1 131 individuals from 58 species in 3 classes (Diplopoda, Chilopoda and Symphyla), 36 genera and 17 families were recorded at Mount Kala. The Diplopoda was the most abundant and diverse class (94.69% and 49 species), followed by Chilopoda (4.51% and 8 species) and Symphyla (0.80% and 1 species). Aporodesmus gabonicus Lucas, 1858 and Karkinikus colonus Attems, 1914 were the most abundant species in the study site. Along the altitudinal gradient, the myriapod species richness decreased in anthropised areas (820 m to 920 m above sea level), reached a maximum in transitional forest (920 m to 1 020 m above sea level) and slightly decreased within the submontane forests (1 020 m to 1 120 m above sea level). Myriapod abundance followed the same trend. However, our results also indicate a high species richness turnover observed between altitudinal levels suggesting that most species are adapted to a particular habitat and could serve as indicators of environmental changes. Accordingly, this study demonstrates a negative relationship between anthropisation and myriapod diversity, as well as the implications towards the management of the Mount Kala forest.

Nitrogen flow patterns in the food system among cities within urban agglomeration: A case study of the Pearl River Delta region

Human activities along the entire food supply-consumption-waste treatment-recycling chain have an essential influence on Nitrogen (N) metabolic features, especially for densely-populated urban agglomeration. A few studies carried out research on detailed analysis and comparison of N flow patterns along the entire food chain among cities, to recognize these influences and accordingly explore effective measures for improving N use efficiencies. In this study, we developed an integrated N flow analysis model to quantify N flows in the food system illustrated by production, processing, consumption, and waste management sectors. Influence of anthropogenic activities on N flow patterns is recognized through comparison among cities and predictions of future scenarios. Using the Pearl River Delta (PRD) region as a case study, we find that (1) in 2016, the annual N import into the production sector in the food system in the PRD region was about 714.5 Gg, among which only 241.6 Gg entered food products. The removal rate of N pollution in all waste stream was about 62.3%, and only 9% of N became resources through reclamation. (2) Among the nine cities in the PRD region, the average amounts of N pollution emission to the air, water, and soil all range from 0.57–5.38 kg cap−1 yr−1, showing significant discrepancy among cities. Cities with relatively lower economic development undertake substantial N pollution embedded in their exported agricultural products. (3) Recycling of agricultural waste is the prior N management measure for Zhaoqing, Jiangmen, and Huizhou, while highly urbanized cities should mainly concentrate on recycling of food waste and sewage sludge. We further put forward suggestions such as cross-city resource recycling to realize better N resource recycling and pollution reduction on the whole urban agglomeration scale. This study provides an in-depth example of depicting N flow patterns and identifying proper N management measures for urban agglomerations.

Major ion chemistry and water quality assessment of groundwater in the Shigaze urban area, Qinghai-Tibetan Plateau, China

Abstract Shigaze city is situated in the southwestern Tibetan Plateau and is the second largest city in the Tibet Autonomous Region. Groundwater is the major source of domestic and drinking water for urban inhabitants. In this study, the major ion chemistry and a water quality assessment of groundwater were studied using geochemical methods and fuzzy comprehensive assessment. Groundwater was classified as slightly alkaline soft and hard freshwater, and the influence of anthropogenic activities on groundwater was relatively weak. The dominant cations and anions were Ca2+ and Mg2+ and HCO3− and SO42−, respectively. Overall, the mean concentrations of major ions in groundwater increase gradually over time, except for NO3−; however, the mean value of pH decreases over time. Most groundwater samples belong to the type of HCO3-Ca, and the groundwater has a trend of evolution from HCO3-Ca to the mixed type. Rock weathering was the main hydrogeochemical process controlling groundwater hydrochemistry, and the dissolution of carbonate and silicate minerals were the primary contributors to the formation of the major ion chemistry of groundwater. Major ions of groundwater in the urban area of Shigaze are below the standard limits, and the groundwater is excellent for drinking according to the fuzzy comprehensive assessment.

Influence of anthropogenic activities on the temperature regime of soils of the South-Western Baikal region

Soil temperature is a key factor controlling many biotic and abiotic processes in soils. Monitoring of the soil temperature in the different habitats is an urgent task, as a rare meteorological network does not allow to assess in detail the hydrothermal regime of different territories. The territory of the study is the Tunka intermountain basin – the area of discontinuous distribution of permafrost. The atmospheric-soil measuring complex was used to investigate the hydrothermal regime of soils. Observations were carried out in automatic mode with a step of 1 hour from 2011 to 2018 year in the soil profiles from the surface to 10 m depth. The studied areas at different times undergo various anthropogenic impacts. It leads to changes in the vegetation cover, morphology structure and granulometric composition of the soils, its temperature and moisture conditions. Thus, the soils at anthropogenically disturbed sites are better warmed up and cools down faster than on undisturbed areas. The depth of the isotherm of +10°C on average is more than 50 cm deep on anthropogenically disturbed areas and the greatest negative temperatures are observed here. The depth of freezing and the magnitude of negative temperatures are directly related to the level of mire waters in the peaty soils. If the water level of the mire increases, as a result of human intervention, the depth of thawing decreased by 20 cm and the winter peat deposit became warmer.

Ecological State of Soils and Tree Vegetation in Urban Park-recreational Landscapes (Based on the Example of Catherine Park in Moscow)

The influence of anthropogenic activity on the quality of urban alluvial soils and conditions of growth and state of tree stands is estimated. The level of negative consequences for natural components is correlated with the degree of human effect. Moisture decreases, the humus content changes in different directions, and the pH of water and electrical conductivity increase in the soil profile. Soil densification and the inhibition of biological activity are recorded in the surface horizons. The coefficient of ecological state of soils decreases by 6–24% compared to the optimum conditions. The correlation analysis showed a significant weak inverse correlation between the state of vegetation and soil quality (the Spearman coefficient was –0.53).

Isotopic and geochemical interpretation of groundwater under the influences of anthropogenic activities

Groundwater resources are increasingly exploited for industrial and agricultural purposes in many arid/semi-arid regions globally. In order to gain a harmonious development among groundwater resources and economic benefits, urgent investigation of the impacts of anthropogenic activities on the groundwater chemistry is required. Understanding hydrochemical mechanism of groundwater in Yinchuan Plain, arid and semi-arid area in Northwestern China, plays a significant role in water resources planning in this ecologically sensitive area. In this paper, a total of 460 phreatic water samples were collected, including 58 water samples containing isotopic data (D and 2H). Results demonstrate that water chemistry type and isotopic data of phreatic water presents a zonation characteristic from west to east and from south to north. In the eastern part of the Helan Mountain (A1 zone), the type of hydrochemistry is mainly HCO3·SO4-Ca·Mg, SO4·HCO3-Ca·Mg, which is mainly recharged by the bedrock fissure water of Helan Mountain. However, in the southern Qingtongxia (A2 zone) are HCO3-Na HCO3-Ca·Mg, which receives irrigation and spring water recharge. Phreatic aquifer in Multi-layered structure zone (A3 zone) reflect multiple recharge sources to the aquifer, the water chemistry demonstrates diverse variations. The anion was dominated by the HCO3, while the cation is dominated by sodium. The predominant controlling factors of phreatic water hydrochemistry are divided into anthropogenic activities and natural conditions. Natural conditions mainly include the existence form and lithology of the aquifer, sources of groundwater recharge, soil salinity, and evaporation, mineral dissolution, ion exchange and adsorption and mixing effect. Meanwhile, among natural factors, minerals dissolution in groundwater is the main process dominating the hydrochemical evolution of the groundwater. The other is anthropogenic activities which can be classified as groundwater pollution, excessive exploitation or excretion of groundwater, and excessive groundwater recharge.

Hydrogeochemical Characteristics and Controlling Factors of the Lhasa River under the Influence of Anthropogenic Activities

Anthropogenic activities have had diversiform impacts on the surrounding river and environments. A study on the surface water of the Lhasa River Basin was undertaken to assess its hydrogeochemical characteristics under the influence of anthropogenic activities. A total of 16 samples collected from the Lhasa River were analyzed for pH, electric conductivity (EC), oxidation-reduction potential (ORP), total dissolved solids (TDS), major cations (K+, Na+, Ca2+, and Mg2+), major anions (Cl−, SO42−, HCO3−, and NO3−), and trace metals. The pH of the analyzed water samples varied from 6.40 to 9.10, indicating alkaline in nature. The EC values varied from 77.3 to 213 μs/cm while the TDS values varied from 73.37 to 217.55 mg/L. HCO3− and SO42− are the dominant anions while Ca2+ and Na+ are the dominant cations in the river water. The concentration of alkaline earth metals (Ca2+ + Mg2+) exceed the alkali metals (Na+ + K+) and HCO3− dominates over SO42− + Cl− concentrations in the majority of the surface water samples. Ca2+-Mg2+-HCO3− and Ca2+-Mg2+-Cl− are the dominant hydrogeochemical facies in the surface water of the area. The water chemistry is mainly controlled by rock weathering with secondary contribution from anthropogenic sources. The content of trace elements in the Lhasa River is low, basically at the natural background value. The high content of individual elements is mainly due to the mineral resource exploitation and geothermal resources in the basin. Countermeasures and attention should be payed to these aspects, such as the construction of water conservancy facilities, urban economic development, the development of mining activities, and sewage and wastewater discharge, so as to protect the water quality and sustainable development of the Lhasa River Basin.

Influence of Anthropogenic Activities on Metals in Arctic Permafrost: A Characterization of Benchmark Soils on the Yamal and Gydan Peninsulas in Russia.

Permafrost-affected region in Russian Arctic is an important study area for investigating fate of trace metals in soils by geological processes and human-induced trace metals through atmospheric deposition. Two plots of soils in Yamal region were selected: Northern Trans-Urals area (PU1, PU2, PU3) adjacent to urban areas and Gydan Peninsula representing reference groups as natural landscapes (Yavai, Gyda, Enysei). The levels of most metals in Urals area were more than those in Gydan Peninsula. In soil profile, Histic horizon revealed the accumulation of most metals. Cd and Pb were classified as metals, which were transported by atmosphere from urban areas and accumulated in surficial organic layers. Gleying processes and cryogenic mass exchanges transported metals from bottom to top layers in mineral horizons. Moreover, gleying horizon functioned as a geochemical barrier for metal transporting below permafrost table. The levels of As, Mn, and Fe were obliviously higher than threshold limit values of Russian Siberia. However, these values cannot represent the natural hydromorphic soils in Arctic tundra. The Geoaccumulation Index (Igeo) were determined for assessing surface soil samples regarding to metals' pollution. The results suggested local geology pollution for Gydan Peninsula and atmospheric transport pollution for Urals area. More investigations with respect to trace metals behavior in permafrost-affected soil profile needed to be studied for understanding levels of trace metals with changes of active layer depth due to climate changing.

Spatio-Temporal Pattern of Primary Production in a Tropical Coastal Wetland (Kodungallur-Azhikode Estuary), South West Coast of India

The Kodungallur-Azhikode Estuary (KAE) is part of the Vembanad wetland ecosystem in south-west coast of India that has recently been designated as the Ramsar site. Modern aquaculture, agriculture and other human activities in the catchment area export huge amounts of organic and inorganic wastes into the KAE. In this perspective, influences of anthropogenic activities on water quality and phytoplankton production in the KAE were studied at multiple sites from July 2009 to June 2010. The linear correlation with salinity (r2=0.179, P<0.01), pH (r2=0.195, P<0.01,) and redox potential (Eh) (r2=0.188, P<0.01) was found to be significant with Chlorophyll-a (Chl-a) and negative correlation with turbidity (r2=-0.212, P<0.01, N=168), nitrate (r2=-0.297, P <0.01, N=168), and total dissolved solids (TDS) (r2=-0.266, P<0.01, N=168). The present study showed annual average gross primary productivity (gross PP) of 1580 ± 388 mgC m-3d-1 and net primary productivity (net PP) 790 ± 472 mgC m-3d-1, with significant monthly variation. The mean Chl-a content in the estuary also showed moderately high values (6.42 ± 3.91 mg m-3). In spatial scale, it varied from 5.07 ± 4.03 mg m-3 at Station II to 7.80 ± 6.07 mg m-3 at Station V. Primary productivity in the estuary was nitrogen limited during pre monsoon period, however average N: P ratio in the water column was well above the Redfield ratio during south west monsoon period (27.9 ± 14.2). Trophic Index (TRIX) analysis in the KAE also showed that estuary experiencing high productivity by the effect of eutrophication.

Identification the Sources of Hg in Jiaozhou Bay 1990

Using investigation data on Mercury (Hg) in May and August, 1990, this paper analyzed the pollution level and identified the source of Hg in Jiaozhou Bay. Results showed that Hg contents in May and August, 1990, were 0.007-0.208 μg L-1 and 0.011-0.055 μg L-1, respectively. The pollution level in May was moderate, compared to slight polluted in August. The major sources of Hg were river discharge, wharf, atmosphere deposition and marine current, whose source strengths were 0.166-0.204 μg L-1, 0.053-0.194 μg L-1, 0.055-0.208 μg L-1 and 0.200 μg L-1, respectively. The various Hg sources indicated the influence of anthropogenic activities on water quality in this bay. Furthermore, marine current became one of the major Hg source 1990, that was to say the background pollution level of Hg in the ocean was high since 1990. In general, source control should be one of the preferred countermeasures for pollution control in marine bay.

Assessment of Physicochemical and Heavy Metal Properties of Groundwater in Edéa (Cameroon)

In order to assess the physicochemical and heavy metal properties of groundwater consumed in Edéa (Cameroon), 8 boreholes were randomly chosen from 8 sites and their suitability was evaluated using three norms viz Cameroonian Norm (NC207:2003-02) and International standards including (CODEX: 108-1981 and European Union, EU:1998). Water samples were collected in triplicates bimonthly and analyzed using standard methods. Physicochemical analysis showed high temperatures with a mean value of (30.26 ±2.4) °C, acidic pH 5.94±0.34 and very weak mineralization leading to an electrical conductivity value of (134, 96 ± 49.59) µS/cm. The relative abundance of major ions was Ca2+>Mg2+>Na+> NH4+>K+ for cations and NO-3> HCO-3-> PO43-> SO42->Cl- for anions. All these ions fell within acceptable limits recommended by NC207:2003-0 boreholes 2, CODEX: 108-1981 and EU: 1998 with an exception for nitrates, ammonium and phosphate contents which were above acceptable limits. Among heavy metals analyzed, results showed that only lead and manganese values were above the standards’; all boreholes were contaminated by Lead while only 32.5% was contaminated by Manganese. The main water types were Mg-Ca-SO43--Cl- and Mg-Ca-HCO3- can’t result to an alteration of the aquifer matrix (dissolution of Gypsum chloride) and influence of anthropogenic activities through infiltration of agricultural, industrial and domestic waste water. These results showed that water of Edéa is not suitable for human consumption and must be appropriately treated before any usage.