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1.
The TRIX index used for the assessment of trophic status of coastal waters has been applied in many European seas (Adriatic, Tyrrhenian, Baltic, Black Sea, and North Sea). However, all these waters are characterized by high nutrient levels and phytoplankton biomass; index calibration based on systems that are principally eutrophic may introduce bias to the index scaling. In the present work the TRIX trophic index is evaluated using three standard sets of data characterizing oligotrophy, mesotrophy, and eutrophication in the Aegean (Eastern Mediterranean) marine environment. A natural eutrophication scale based on the TRIX index that is suitable to characterize trophic conditions in oligotrophic Mediterranean water bodies is proposed. This scale was developed into a five-grade water quality classification scheme describing different levels of eutrophication. It is questionable whether this index can form a universal index of eutrophication or the scaling of TRIX should be region specific.  相似文献   

2.
The Augusta basin, located in SE Sicily (southern Italy), is a semi-enclosed marine area, labelled as a highly contaminated site. The release of mercury into the harbour seawater and its dispersion to the blue water, make the Augusta basin a potential source of anthropogenic pollution for the Mediterranean Sea. A mass balance was implemented to calculate the HgT budget in the Augusta basin. Results suggest that an average of ~0.073 kmol of HgT is released, by diffusion, on a yearly basis, from sediments to the seawater, with a consequent output of 0.162 kmol y(-1) to coastal and offshore waters; this makes the Augusta area an important contributor of mercury to the Mediterranean Sea. Owing to the geographical location of the Augusta basin, its outflowing shelf-waters are immediately intercepted by the surface Atlantic Ionian Stream (AIS) and mixed with the main gyres of the eastern Mediterranean Sea, thus representing a risk for the large-scale marine system.  相似文献   

3.
Several local surveys on the submerged vegetation have been conducted in past decades along the Finnish Baltic coastal areas. Surveys have been carried out by using various methods,which make the temporal comparisons of the results difficult.The need of a joint programme for coastal phytobenthic monitoringis emphasised by the Nordic Council of Ministers and HELCOM. TheFinnish coastal phytobenthic monitoring programme complements theBaltic HELCOM monitoring programme (COMBINE). It is primarily designed to reveal the effects of eutrophication. The programmeincludes general principles for selection of monitoring areas aswell as a proposal for monitored habitats, communities and species. The need of evaluated and tested field methods, datacollecting, interpretation and data storage are addressed in theQuality Assurance part. The cost-efficiency is secured by integrating the phytobenthos programme with the coastal water monitoring for obtaining the supporting data such like salinity,temperature and nutrients. In the design of the monitoring programme a special interest is paid on areas with high protection values such as Natura 2000 or HELCOM's BSPA (Baltic Sea Protected Areas) or on aspects that would support the implementation of the EU Water Framework Directive.  相似文献   

4.
The water quality management of The Netherlands' part of the North Sea (57 000 km2 continental shelf of which 7600 km2 is territorial sea to 12 miles) and the Wadden Sea (a wetland area behind the northern coastal islands), is described on the basis of recent scientific studies and governmental policy documents. The links with international conventions and treaties are mentioned. The overall water quality in these areas has significantly deteriorated over the last century, notably since the post-war industrial revival, due to a great number of emissions of heavy metals and organochlorine substances. A dramatic decline of seals and porpoises has occurred. However, over the last few years some emissions have been reduced. A national ecological research programme for the North Sea is developing. Monitoring is concentrated on levels of pollutants as well as on effects upon biota. Baseline standards are now being developed as references for further action against pollution. If the recent trend towards improvement is to continue, it requires that the increased economic activities (notably the mining of oil and gas, petrochemical production, and incineration and dumping of chemical wastes) be kept sufficiently under control. A need is felt for a continued rational harmonization and planning of all activities on the North Sea. An even more stringent planning is required for the Wadden Sea which is now an international nature reserve under the Wetland Convention and is eligible for designation as a Biosphere Reserve under the UNESCO-MAB-programme. The river Rhine as greatest polluter of the North Sea and Wadden Sea urgently needs a clean-up.  相似文献   

5.
从法律层面,法规、规章层面,地方性法规层面,技术标准和规范层面,中长期规划性文件层面等方面分析中国地下水环境保护体系的现状,针对地下水立法滞后,存在法律空白,处罚力度不足,管理部门责任不明等问题,提出,应完善地下水环境保护监管体制,健全地下水环境监测和评价制度,建立地下水资源市场调节机制。  相似文献   

6.
近岸海域富营养化评价方法的研究进展和比较   总被引:3,自引:0,他引:3  
富营养化是沿海经济和社会发展面临的主要环境问题,近些年基于科学研究成果与经验,国外近岸海域富营养化评价方法已有长足进步,与之相比,中国现行方法仍处于初级阶段。通过文献资料分析,总结了奥斯陆-巴黎委员会、赫尔辛基委员会、欧盟水框架指令、美国海洋和大气管理局等富营养化评价方法的特点,并在应用范围、评价指标体系、标准、数据要求、程序及结果等方面进行了比较。针对中国目前近岸海域监测现状提出建议,为建立适合中国近岸海域富营养化特点的评价方法提供借鉴和参考。  相似文献   

7.
The seagrass Posidonia oceanica is extensively monitored in Mediterranean coastal waters and is an ideal candidate for an eco-regional assessment of the coastal ecosystem. The aim of this study is to evaluate the potential of P. oceanica as eco-regional indicator for its assessment at the scale of Mediterranean basin. For this purpose, regional and national P. oceanica monitoring programmes are identified, and their data and metadata are collected and compared in terms of objectives, strategies, sampling designs and sampling methods. The analysis identifies a number of issues concerning data quality, reliability and comparability. In particular, the adoption of different sampling designs and methods may introduce relevant errors when comparing data. The results of this study stress the necessity of carefully planning monitoring programmes. Moreover, it highlights that the adoption of a number of common tools would facilitate all Mediterranean monitoring activities and allows an optimisation of management efforts at an eco-regional scale.  相似文献   

8.
A scoring system based on nutrient concentrations was developed to assess coastal water quality according to the trophic level. Three nutrient data sets from eutrophic, mesotrophic and oligotrophic waters were used as the reference information for setting up a semi quantitative water quality scale (from 0 to 5) to express different nutrient loadings. The validity and sensitivity of the method was applied to a number of stations spaced out along the coastal area of Rhodes (Greece). A score for each nutrient/sampling site was calculated and the scorecard formed, was the data matrix used for numerical classification of the stations. The results showed (a) good discrimination between cutrophic, mesotrophic and oligotrophic waters (b) nitrate among the nutrients showed the maximum sensitivity in characterising pollution levels. The reference data sets used for assessing eutrophication levels ensured the objectivity of the method. The proposed method is described step-by-step and it is suggested that the method can be further adapted to describe other forms of pollution becoming a useful quantitative technique in coastal management practices.  相似文献   

9.
Heavy Metals Monitoring using Bivalves from Mediterranean Sea and Red Sea   总被引:1,自引:0,他引:1  
The concentrations of heavy metals (Cd, Co, Cu, Fe, Mn, Ni, Pd and Zn) were measured in the Bivalves (Modiolus auriculatus and Donax trunculus) collected from the Egyptian coasts of Mediterranean Sea and Brachiodonates sp. from the Egyptian coasts of Red Sea. The average concentrations of the heavy metals analyzed exhibited the following decreasing order: Fe > Zn > Cu > Mn > Ni > Co > Pb > Cd for both Mediterranean Sea and Red Sea. The analyses of Cd, Co, Ni, Pb, and Zn showed higher average concentrations for samples collected from Red Sea than that collected from Mediterranean Sea, while Fe, Cu and Mn showed the reverse results. Fe was used as a normalizing agent for all studied metals and exhibited presence of two locations from each of Mediterranean Sea and Red Sea have anthropogenic inputs of heavy metals. These results suggest that the coastal area in both Mediterranean Sea and Red Sea of Egypt might be considered relatively unpolluted with heavy metal.  相似文献   

10.
Combating desertification in natural rangelands has recently become a priority in large parts of southern Africa. Rangeland managers, farmers, scientists, conservationists and land users have been applying a variety of restoration technologies to address this problem. Bush encroachment, as part of the desertification process, involves the natural replacement of the herbaceous plant cover by undesirable problem woody species. The active and passive restoration technologies that are applied, are mainly based on indigenous knowledge and include the chemical, mechanical or manual reclamation of unproductive rangelands, as well as the combating of woody and alien species encroachment. Indigenous practices and knowledge play a major role in the effectiveness and success rate of these technologies. This project faces the challenge of bringing together both local and scientific knowledge in a single user-friendly, computerised Decision Support System (DSS) which is directly accessible by land users to support them in the process of decision making, concerning the combating of desertification. Case studies from central and northern Namibia were used to combine qualitative and quantitative data to develop this Decision Support System. The DSS currently consists of two databases and an expert system, which evaluates the results of land users’ management practices, and provides easily accessible information and advice for participants in the system, based on the incorporated data. The DSS is also linked to national and international web sites and databases to offer a wider range of information on technologies concerning agricultural and conservation practices.  相似文献   

11.
Although the majority of rivers and streams in the Mediterranean area are temporary, no particular attention is being paid for such systems in the Water Framework Directive (WFD). A typical temporal Mediterranean river, draining an intensively cultivated basin, was assessed for its chemical status. Elevated concentrations of nitrates and salts in river water as well as nutrients and heavy metals in river sediments have been attributed to agricultural land uses and practices and point sources of organic pollution. A scheme for the classification of the river's chemical status (within the ecological quality classification procedure) was applied by combining pollution parameters in groups according to related pressures. In light of the temporal hydrological regime and anthropogenic impacts, sediment chemical quality elements were considered, in addition to hydrochemical ones. Despite the extensive agricultural activities in the basin, the majority of the sites examined showed a good quality and only three of them were classified as moderate. For the classification of the chemical quality of temporary water bodies, there is a need to develop ecologically relevant salinity and sediment quality standards.  相似文献   

12.
Cumulative impact assessment (CIA) is the process of systematically assessing a proposed action's cumulative environmental effects in the context of past, present, and future actions, regardless of who undertakes such actions. Previous studies have examined CIA efforts at the federal level but little is known about how states assess the cumulative impacts of nonfederal projects. By examining state environmental review statutes, administrative rules, agency-prepared materials, and a national survey of the administrators of state environmental review programs, this study identifies the legal and administrative frameworks for CIA. It examines current CIA practice, discusses the relationship between CIA policy and its implementation, and explores the opportunities for improvement. The results of the study show that twenty-nine state environmental review programs across twenty-six states required the assessment of cumulative environmental impacts. More than half of these programs have adopted specific procedures for implementing their policies. Some programs assessed cumulative impacts using a standard review document, and others have created their own documentations incorporated into applications for state permits or funding. The majority of programs have adopted various scales, baselines, significance criteria, and coordination practices in their CIA processes. Mixed methods were generally used for data collection and analysis; qualitative methods were more prevalent than quantitative methods. The results also suggest that a program with comprehensive and consistent environmental review policies and procedures does not always imply extensive CIA requirements and practices. Finally, this study discusses the potential for improving existing CIA processes and promoting CIA efforts in states without established environmental review programs.  相似文献   

13.
The Istanbul Strait, which separates the European and the Asian parts of Istanbul, is one of the narrowest straits in the world that is used for international shipping. The Strait has very special ecological conditions in terms of marine environment (atmospheric/oceanographic conditions, plant and animal diversity) and terrestrial environment. It also has roles as biological corridor and biological barrier between the Mediterranean Sea and the Black Sea and form an acclimatization zone for migrating species. Due to being the only maritime access for the neighboring Black Sea states and the Central Asian Turki Republics, the Istanbul Strait has been exposed to dense marine traffic for centuries and substantial increase has occurred in size and tonnage of the ships passing through the Strait with hazardous cargo varieties and amounts they carry. Increase in the number of vessels that navigates on the Strait and being on the transportation way of hazardous and dangerous materials pose serious environmental and safety hazards for the Istanbul Strait, Marmara Sea and the surrounding residential areas. Geographic and oceanographic features of the Istanbul Strait makes the navigation on the Strait rather difficult and consequently the Strait has faced many casualties that caused severe environmental problems due to thousands tons of oil spill occurring in recent decades.  相似文献   

14.
The interaction effects of abiotic processes in the production of phytoplankton in a coastal marine region off Cochin are evaluated using multiple regression models. The study shows that chlorophyll production is not limited by nutrients, but their physiological regulations (responses to nutrients, pH, temperature and salinity) are mainly responsible for the increased biological production. The model explaining 77% of variability for chlorophyll a production is indicative of preconditioning of the coastal waters. The phytoplankton production is found to be sensitive to the environment, which varies seasonally. Further, the study suggests that supply of organic matter and grazing of zooplankton (not included) would improve the model efficiency. Despite this, the good agreement in the computed and measured chlorophyll a values shows that step-up multiple regression model is a useful tool to understand the influence of environmental variables on the production of phytoplankton in these coastal waters.  相似文献   

15.
Natural background concentrations of nutrients are needed for the assessments of eutrophication processes and their status. Natural background concentrations of total nitrogen (TN) and total phosphorus (TP) were modelled for the rivers discharging into the German Bight and the Rhine considering individual catchment sizes, freshwater flows and soil types. These data were validated by comparison with data from unpolluted rivers. The consistency of modelled and some compiled nutrient concentrations was confirmed by their area-specific load dependency on freshwater discharges. Pristine inorganic nutrient concentrations were deduced from modelled relations to TN and TP in unpolluted rivers. Pristine nutrient gradients between rivers and offshore waters were estimated by linear mixing until a salinity of 32, continued by hyperbolic fits towards recent mean offshore values (salinity 34.5?C35). Based on these gradients and recent mean salinities, maps of pristine surface gradients were plotted for the whole German Bight. Variability was transferred from recent conditions as percentage of standard deviation. Reported historical nutrient data and concentrations from unpolluted rivers, coastal and offshore North Sea waters are discussed concerning their relations to natural background conditions.  相似文献   

16.
This research is focused on the coastline evolution monitoring and its potential change estimation by remote sensing techniques using multi-temporal Landsat images at the southeast coasts of the Mediterranean Sea in Turkey. The study area includes the coastal zone located in the Cukurova Delta coasts. The Cukurova Delta has accreted toward the Mediterranean Sea as a result of sediment discharge and transport from Seyhan and Ceyhan rivers. These processes have caused the morphological changes (accretion or erosion) of coastline along some parts of the southeast coasts of the Mediterranean Sea. In this study, coastline changes were researched by using radiometrically and geometrically corrected multi-temporal and multi-spectral data from Landsat Multispectral Scanner dated 1972, Thematic Mapper dated 1987, and Enhanced Thematic Mapper dated 2002. In the image processing steps, mosaicing, subset, Iterative Self-Organizing Data Analysis Technique classification, band ratioing (B5/B2), edge detection, and overlay techniques were used to carry out coastline extraction and the Digital Shoreline Analysis System was used to calculate rate of coastline changes. As a result of the analysis, in some parts of the research area, remarkable coastline changes (more than 2,900 m withdrawal and ??24.50 m/year erosion) were observed for a 30–year period.  相似文献   

17.
Köyce?iz Lake is located in the south-western part of Turkey. The area between the Köyce?iz Lake and the Mediterranean Sea is covered with four small lakes and several canals. The surroundings of the lake, canals and forests have a great potential as a reproduction areas for Mediterranean Sea turtles (Caretta caretta) and sheltering place for various animals. In the vicinity of this system there are agricultural areas and small settlements. In this region the most important economic activities are tourism and fisheries. However, the lake is currently threatened by pollution because of (1) non-point source pollution (agriculture); (2) point sources (land-based fish farms); (3) inefficient sewerage systems; (4) uncontrolled soil erosion in its drainage basin; (5) inappropriate flood control measures; and (6) channel traffic. This study evaluates the influence of its influent creeks namely Namnam and Yuvarlakçay Creek on the water quality of Köyce?iz Lake, mainly because the creeks are believed to be responsible for the major pollutant load reaching the lake. Accordingly, this study demonstrates (1) change in the water quality of Köyce?iz Lake from 2006 to 2007; (2) the water quality classification of the major influent creeks feeding Köyce?iz Lake; and (3) how land-based fish farm influences Yuvarlakçay Creek water quality in a Köyce?iz–Dalyan Specially Protected Area.  相似文献   

18.
The subtropical Hong Kong (HK) waters are located at the eastern side of the Pearl River Estuary. Monthly changes of water quality, including nutrients, dissolved oxygen (DO), and phytoplankton biomass (Chl-a) were routinely investigated in 2003 by the Hong Kong Environmental Protection Department in three contrasting waters of HK with different prevailing hydrodynamic processes. The western, eastern, and southern waters were mainly dominated by nutrient-replete Pearl River discharge, the nutrient-poor coastal/shelf oceanic waters, and mixtures of estuarine and coastal seawater and sewage effluent of Hong Kong, respectively. Acting in response, the water quality in these three contrasting areas showed apparently spatial–temporal variation pattern. Nutrients usually decreased along western waters to eastern waters. In the dry season, the water column was strongly mixed by monsoon winds and tidal currents, which resulted in relatively low Chl-a (<5 μg l?1) and high bottom DO (>4 mg l?1), suggesting that mixing enhanced the buffering capacity of eutrophication in HK waters. However, in the wet season, surface Chl-a was generally >10 μg l?1 in southern waters in summer due to halocline and thermohaline stratification, adequate nutrients, and light availability. Although summer hypoxia (DO <2 mg l?1) was episodically observed near sewage effluent site and in southern waters induced by vertical stratification, the eutrophication impacts in HK waters were not as severe as expected owing to P limitation and short water residence time in the wet season.  相似文献   

19.
The ctenophore Bolinopsis vitrea has been rarely observed in the Mediterranean Sea. A bloom of B. vitrea is here reported for the first time in the southern Adriatic Sea in the spring and summer of 2009, together with its effect on the plankton of Kotor Bay. Ctenophores were found below 5 m depth only. Results of the investigation indicate that mass occurrence of B. vitrea could have a great impact on the Kotor Bay ecosystem. Their predation on copepods would reduce grazing pressure on phytoplankton, favouring an uncommon bloom of the latter. It is evident that B. vitrea are capable of altering rapidly the composition and biomass of coastal plankton communities when present in large masses. This first evidence of such events for this species may indicate changes in the functioning of marine ecosystems of the southern Adriatic.  相似文献   

20.
Coastal aquaculture is faced with extreme variation in water quality. The Deeba Triangle on Lake Manzala is the largest marine coastal aquaculture-producing area on the Egyptian Mediterranean. Samples from 16 ponds were taken during four seasons (2014–2015), to investigate the variation of 12 water quality parameters at that region. We tested the hypothesis that there is no spatial or temporal variation in water quality of the fish ponds. Fish ponds were statistically clustered into three groups (p?=?0.0005) coincident with their geographical location. Hypersaline and transparent waters characterized the western ponds; higher dissolved oxygen and higher nutrients characterized the central region. These spatial differences were principally due to variations in salinity and nutrients of the water sources used for irrigation of the ponds and to differences in the aeration management styles. Strong seasonality was seen in water temperature (following air temperature), nutrients, and turbidity (following the seasonal cycles of various water sources from the Lake Manzala and the seasonality of the petrochemical plants effluents close to these ponds). We conclude that municipal effluents significantly affected, spatially and temporally, the quality of the irrigation water used for coastal aquaculture purposes, which consequently might affect fish yield.  相似文献   

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