Microbial and nutrient pollution of coastal bathing waters in Mauritius

The coastal pollution problem in Mauritius is exacerbated by the hydrogeology of the volcanic substratum. Bacterial contamination of bathing waters and nutrients, water temperature, salinity, and dissolved oxygen (DO) were monitored at three different spatial and temporal scales along the coastline of Mauritius during 1997-1998. Standard techniques for water sample collection and analysis set by the American Public Health Association [APHA. Standard methods for the examination of water and wastewater. 19th ed. Washington, DC: APHA, 1995.] were used at: (a) 16 sites around the island over a period of 7 months; (b) 12 stations along a recreational beach over an 18-month period; and (c) at an underground freshwater seepage point over 1 day. Total coliform (TC), faecal coliform (FC), and faecal streptococci (FS) contamination reported during all surveys varied randomly (e.g., with maximum densities in the ranges of 346-2020 TC, 130-2000 FC, and 180-1040 FS at one site) and at times exceeded the established EEC and Environment Protection Agency (EPA) standards for bathing water (e.g., in >90% of samples) to qualify for beach closure. Computed FC:FS ratios were used to pinpoint human faecal matter as the main source of contamination. Nitrate, phosphate, and silicate concentrations in seepage water were high (3600-9485, 38-105, and 9950-24,775 microg l(-1), respectively) and a cause for concern when compared with levels (5-845, 5-72, and 35-6570 microg l(-1), respectively) in cleaner lagoon water samples. Statistical analysis showed significant correlations (for TC and NO3: r=.75, P<.02; for TC and PO4: r=.779, P<.02; for TC and SiO4: r=.731, P<.05; for FC and NO3: r=.773, P<.02; for FC and SiO4: r=.727, P<.05; for FS and SiO4: r=.801 P<.01) between microbial densities and nutrients recorded, confirming the pathogen-contaminated water to be highly eutrophic. There is an urgency for Mauritius to properly address the issue of sewage treatment and wastewater discharge to safeguard its coastal environment, public health, and tourism expansion.     

The present condition of the Vistula river catchment area and its impact on the Baltic Sea coastal zone

This review paper describes the state of the Vistula basin and the Baltic Sea area. The article is divided into two parts concerning the river and the Baltic coastal zone, respectively. Each part describes the geography and the environmental state of the region and gives an overview of the socio-economic conditions. The environmental state of the study regions is described in terms of annual monitoring data for the main physico-chemical and biological parameters. The data cover the last decade. The socio-economic overview includes parameters such as e.g. population density, industrialization, agricultureand land use.SI: Pirrone     

Reference conditions for rivers of the German Baltic Sea catchment: reconstructing nutrient regimes using the model MONERIS

We introduce an approach for establishing reference conditions (RC) for rivers of the German Baltic Sea catchment, based on predictive modelling. An extensive data set of statistics from the year 1880 was coupled with literature data, providing a comprehensive basis for the calculation of regional historical nutrient emissions into rivers, river nutrient concentrations, and nutrient loading into the sea. Four different scenarios were calculated: scenario 1 assumed RC following previously established criteria for lakes (Poikane et al. in Environ Manag 45(6):1286–1298, 2010), scenario 4 applied the nutrient emission conditions of 1880 (considering non-intensive land usage, the presence of tile drainage systems, sewer systems, and the human population from 1880), and scenarios 2 and 3 considered intermediate conditions. Our results showed that nutrient emissions from scenario 1 accounted for approximately one-tenth of the currently observed total nitrogen (TN) and total phosphorus (TP) emissions. The nutrient emissions calculated for 1880 (scenario 4) were found to be 47 % (TN) and 55 % (TP) higher than those calculated considering reference lake conditions (scenario 1). Our results suggest that RC nutrient concentrations in rivers in the German Baltic Sea catchment were clearly below 0.05 mg/l for TP and 1 mg/l for TN. This range is in accordance with historical and calculated pristine nutrient concentrations from other rivers in similar catchments.     

Cost-effective nutrient reductions to coupled heterogeneous marine water basins: An application to the Baltic Sea

In this paper, the role of nutrient transports between marine basins is investigated for cost-effective solutions to predetermined marine basin targets. The interdependent advective nutrient transports as well as retentions among the seven major marine basins of the Baltic Sea are described by input-output analysis. This is in contrast to prior economic studies of transboundary water pollution that include only direct transport between the basins. The analytical results show that the difference in impacts between transport specifications depends mainly on the openness of the basins, that is, their transports with other basins. The application on Baltic Sea shows significant differences in costs and policy design between the nutrient transport specifications. The reason is that the Sea is characterized by long water and nutrient residence times, so relatively large part of nutrients are transported among basins.     

Monitoring the coastal waters of Kuwait for chemical mutagens

Industrial and municipal effluents are currently dumped in the coastal waters of Kuwait. They contain a variety of pollutants, some of which are potentially mutagenic and/or carcinogenic. For detection of these pollutants, marine algae (seaweeds) and clams were used as bioindicators of pollutants in the marine environment. Bacterial mutagenicity assays using fluctuation analysis and the Ames test were used to detect both frameshift and basechange mutagens. The results suggest that the majority of sites along the coast of Kuwait are polluted with low concentrations of mutagenic pollutants. The sources of input and the chemical nature of these pollutants were not determined.     

Seasonal variations in 228Ra/226Ra ratio within coastal waters of the Sea of Japan: implications for water circulation patterns in coastal areas

In this study, low-background gamma-spectrometry was used to determine the (228)Ra/(226)Ra ratio of 131 coastal water samples from various environments around Honshu Island, Japan (mainly around Noto Peninsula) at 1-3 month intervals from April 2003 until September 2005. Spatial variation in (228)Ra/(226)Ra ratios was also assessed by analyzing 34 coastal water samples from five areas within the Sea of Japan during May and June 2004. The (228)Ra/(226)Ra ratio of coastal water from all sites around Noto Peninsula shows seasonal variation, with minimum values during summer ((228)Ra/(226)Ra=0.7) and maximum values during autumn-winter ((228)Ra/(226)Ra=1.7-2). This seasonal variation is similar to that recorded for coastal water between Tsushima Strait and Noto Peninsula. The measured lateral variation in (228)Ra/(226)Ra ratios within coastal water between Tsushima Strait and Noto Peninsula is only minor (0.5-0.7; May-June 2004). Coastal waters from two other sites (Pacific shore and Tsugaru Strait, north Honshu) show no clear seasonal variation in (228)Ra/(226)Ra ratio. These measured variations in (228)Ra/(226)Ra ratio, especially the temporal variations, have important implications for seasonal changes in patterns of coastal water circulation within the Sea of Japan.     

Plutonium concentrations in waters from the southern Baltic Sea and their distribution in cod (Gadus morhua) skin and gills

The concentrations of (238)Pu and (239+240)Pu in water samples and suspended particulate fractions, as well as in colloidal fraction from the southern Baltic Sea are presented. The (239+240)Pu concentration in surface seawater samples fall within range from 5.2 mBq.m(-3) for Gdańsk Bay to 150 mBq.m(-3) for Pomeranian Bay, most of which (from 52 to 96%) constituted filterable forms (相似文献   

Level and origin of iodine-129 in the Baltic Sea

Environmental samples, such as seawater, seaweed, lake water, lake sediment and grass collected from the Baltic Sea area were analyzed for 129I and 127I by radiochemical neutron activation analysis. In 2000, the concentration of 129I in the seawater from Borholm and M?en in the Baltic Sea has reached 6.0 x 10(-13) and 16 x 10(-13) g/l, respectively, these are more than two orders of magnitude higher than the global fallout level. The highest value of 270 x 10(-13) g/l being found in the seawater from the Kattegat. By comparison of the level of 129I in the lake water and precipitation in this region, it is estimated that more than 95% of 129I in the Baltic Sea originates from reprocessing emissions, especially from the French nuclear fuel reprocessing plant at La Hague. More than 30% of 129I in the south Baltic and 93% in the Kattegat directly originates from the marine discharges of the European reprocessing plants.     

A particle-tracking method for simulating the dispersion of non-conservative radionuclides in coastal waters.

A particle-tracking method has been used to simulate the dispersion of non-conservative radionuclides in the sea. Three dimensional turbulent diffusion and the interactions between water, suspended matter and bottom sediments are simulated using a stochastic method. Kinetic transfer coefficients, as in finite difference models, are used to describe the transfers between the liquid and solid phases. Deposition of suspended matter and erosion of sediment are also included in the model. The method has been applied to simulate the dispersion of 137Cs and (239,240)Pu in the English Channel and the results have been compared with those of a finite difference model. The results from both techniques are, in general, in good agreement.     

137Cs and 90Sr behavioural regularities in the southeastern part of the Baltic Sea

Variations in 137Cs concentrations were investigated over the period 1986-1997 in the southeastern part of the Baltic Sea, following the Chernobyl power plant accident. The rate of "self-cleaning" was demonstrated to be very slow, the average concentration of 137Cs in 1996 being almost the same as that measured directly after the accident, in 1986. Measurements of both 137Cs and 90Sr concentrations generally revealed homogeneous distributions in this region of the Baltic Sea, though patchy distributions did develop under some hydrometeorological conditions. Specifically, the 137Cs concentration distribution became heterogeneous with values varying in the range 60-92 Bq/m3 under south-southwesterly wind conditions whilst the 90Sr concentration distribution developed similar characteristics with values ranging from 15 to 64 Bq/m3 under east-southeasterly wind conditions. In addition, in coastal waters, over extensive periods of north-northwesterly winds in 1995, 137Cs concentrations increased to values 1.5-2 times the overall average concentration, which was registered in 1986 and 1996. These data therefore reveal a continuing significant pollution of the waters of the Baltic Sea resulting from the Chernobyl power plant accident, a pollution compounded by the slow rate of radionuclide self-cleaning and significant probability of sudden regional concentration increase.     

Temporal trends for 99Tc in Norwegian coastal environments and spatial distribution in the Barents Sea

The objective of this study was to reassess 99Tc transit times and transfer factors, from Sellafield to northern Norway, and to determine the extent of 99Tc migration to the Barents Sea. Filtered seawater samples were collected on a monthly basis from Hilles?y, northern Norway, and in February 1999 from the Barents Sea. Results showed an increase in levels of 99Tc at Hilles?y where activity concentrations have increased from a baseline of 0.2-0.4Bq m(-3) to a maximum of 1.6 Bq m(-3). A transit time of 42 months and a transfer factor of 6Bq m(-3) per PBq a(-1) have been derived, using cross-correlation analysis. The current study predicts that future levels are unlikely to increase dramatically over the levels observed in 1998. Levels of 99Tc in the Barents Sea ranged from 0.2 Bq m(-3) to 1.1 Bq m(-3) showing the influence of new 99Tc inputs by early 1999.     

Nutrient export by rivers to the coastal waters of China: management strategies and future trends

We analyzed past and future trends in river export of dissolved nitrogen (N) and phosphorus (P) to the coastal waters of China, for a selection of rivers, as calculated by the Global NEWS models (Nutrient Export from WaterSheds). Over the period 1970–2000, river export of dissolved nutrients increased considerably, especially of dissolved inorganic N and P. Anthropogenic sources of N and P in rivers have become increasingly important, in particular N and P losses from agriculture. We tested the sensitivity of calculated nutrient export by rivers to changes in selected controlling factors. The calculated export of dissolved N and P is sensitive to changes in hydrology, synthetic fertilizer use and manure excretion in river basins. Changes in sewage inputs have large effects on dissolved inorganic P export. We analyzed future trends up to 2050 for several scenarios to illustrate the combined effects of selected management options. In the Base Scenario, the N and P export by the selected rivers increases considerably between 2000 and 2030. The increase continues from 2030 to 2050 except for DIP. Strategies to reduce N and P export by rivers include changes in agriculture, sewage and energy use. Changes in agriculture have the largest impact on future dissolved N and P river export to the coastal waters of China. The effectiveness of reduction strategies differs between nutrient forms and basins.     

Trends in the spatial and temporal distribution of 129I and 99Tc in coastal waters surrounding Ireland using Fucus vesiculosus as a bio-indicator

Spatial and temporal trends in (129)I and (99)Tc concentrations around the Irish coastline have been evaluated using Fucus vesiculosus as a bio-indicator. (129)I concentrations in a recent set of seawater samples have also been recorded and reveal an identical spatial pattern. Concentrations of (129)I in Fucus from the northeast coast of Ireland proved to be at least two orders of magnitude higher than concentrations in Fucus from the west coast. The (129)I content of Fucus increased significantly between 1985 and 2003, in line with increases in discharges of (129)I from the Sellafield nuclear reprocessing plant. Similar trends were observed in the case of (99)Tc. (129)I/(99)Tc ratios in Irish seawater were deduced from the Fucus data, and compared to ratios in discharges from Sellafield and from the French reprocessing plant at Cap de la Hague. Levels of (129)I and (99)Tc in Fucus from the west coast were found to be enhanced with respect to levels in seaweeds from other regions in the Northern Hemisphere unaffected by discharges from nuclear installations such as those referred to.     

Contamination of the southern Baltic Sea with 137Cs and 90Sr over the period 2000-2004

Changes of the (137)Cs activity concentrations in the southern Baltic Sea waters were investigated over the period 2000-2004 and distribution of the (90)Sr concentrations was determined in 2004. In the discriminated period further decrease of (137)Cs concentrations was observed. The average activity concentration of (137)Cs declined from 59.4Bq/m(3) in 2000 to 45.1Bq/m(3) in 2004. The greatest changes of (137)Cs activities occurred in 2003 as a consequence of the medium-size inflow of a saline waters from the North Sea. This inflow affected (137)Cs activities as well as its distribution in the Baltic Sea. Changes in (90)Sr activity concentrations proceeded at much slower rate. The average activity concentration of (90)Sr was equal to 8.7Bq/m(3) in 2004. The annual fluvial (137)Cs fluxes from the Vistula river were also estimated. In 2000, the (137)Cs load from Vistula was of an order of 0.15TBq/year, and in 2004 0.05TBq/year.     

The geomorphology and ecosystem service economic value baselines of tributary watersheds in Malaysia

Environment, Development and Sustainability - This study presents how a cluster of tributary watersheds was evaluated for geomorphology and ecosystem service economic value baselines. Tributary...     

A simple and rapid method for analyzing radon in coastal and ground waters using a radon-in-air monitor

We have developed a simple and portable technique for measuring moderately high levels of 222Rn (t1/2=3.8d) in natural waters such as coastal water, groundwater, and river water. The water sample is carefully collected in a glass bottle, and the sample bottle is connected to a radon-in-air monitor in a closed air-loop mode. By purging air through the sample, radon is emanated from the water until a chemical equilibration is obtained between the two phases. The radon in the air loop is determined using the radon-in-air monitor. Then, the radon in water is calculated by a radon-partitioning factor between water and air for a measured water temperature. This technique is especially convenient for determination of 222Rn in natural waters on field sites, since it eliminates the preparation of He gas, cold traps, and alpha-scintillation cells and counter, which are required for traditional radon emanation methods.     

Biogeochemistry of Chinese estuarine and coastal waters: nutrients, trace metals and biomarkers

The dissolved and particulate trace metals in large and middle-sized Chinese rivers remain comparable with other less-disturbed world systems. Levels of nutrients in Chinese rivers are high due to erosion over the drainage area and the application of chemical fertilizers, which induces an N/P ratio up to 100–1,000. The concentrations of organic pollutants in Chinese rivers are ranked at the lower end of those of world systems; however, pollution has been identified in coastal waters from north to south of the country. In estuarine and coastal waters, dissolved trace metals illustrate a feature of remobilization, while non-conservative distribution is observed, with exceptions for iron and aluminum. Particulate trace metals demonstrate a fairly stable distribution along the salinity gradient, when the absolute concentration is normalized to reference materials. In high-turbidity estuaries, seaward nutrient flux can be increased by a factor of 5–10. Finally, the N/P ratio approaches 10–20 at the interior of the East China Sea, indicating that in coastal regions photosynthesis changes from P to N and Si limitations. Electronic Publication     

Inactivation of coliform bacteria in Black Sea waters due to solar radiation

The effects of solar radiation and temperature on bacterial die-off rates in Black Sea coastal waters using total coliform as the indicator organism were studied. Coliform die-off experiments were carried out in seawater samples collected along the coastline. The experiments were conducted in beakers filled with seawater that were kept at constant temperatures and exposed to solar radiation. The membrane filter technique was used for the coliform analysis. Temperature ranging between 9 and 26 degrees C and solar radiation between 20 and 60 cal/cm(2) h were tested. Experiments in the dark were also conducted to isolate the effect of solar radiation from the other factors and, furthermore, to determine the effect of temperature on bacterial die-off. The solar radiation was found to be the most significant factor affecting the mortality of coliform bacteria.     

The inflow of (238)Pu and (239+240)Pu from the Vistula River catchment area to the Baltic Sea

The aim of the work was to estimate plutonium inflow from the Vistula River’s catchments area to the Baltic Sea. There were differences in plutonium activities depending on season and sampling site. The highest activities of ²³⁸Pu and ^239+240Pu were transported from the Vistula River watershed to the Baltic Sea in spring and the lowest in summer. Annually, the southern Baltic Sea is enriched via the Vistula River with 10.3 MBq of ²³⁸Pu and 89.0 MBq of ^239+240Pu. The enhanced concentration of plutonium in water from the Vistula River is the result of its runoff from the Vistula drainage area, mostly from snowmelt, enhanced rainfalls and leached materials from river bed.