Elefsis Gulf Research Articles

Toward a Sustainable Blue Economy in the Coastal Zone: Case Study of an Industrialized Coastal Ecosystem in Greece

Representing 9% of the land worldwide, the coastal zone is a highly populated part of the land, where economic and social growth continuously arise. An expected consequence of rapid development on the coastal zone is the creation of significant environmental pressures connected to human activities. Within this framework, the need to use the ecosystem services concept under the prism of sustainable development has risen to increase the provision of services to the people through an ecosystem approach using the human–environment interaction. The aim of this paper is to form an integrated approach for sustainable blue economy in a coastal ecosystem, using the SDGs and the ecosystem services frameworks and exploring the interlinkages of the ecosystem’s parameters from both sides. The outcome of this study is the formation of a decision-making tool for sustainable blue economy in a coastal ecosystem, which classifies the SDGs with a specific factor, according to their importance for the sustainable blue economy, and helps stakeholders prioritize their actions toward the achievement of sustainability in the specific ecosystem. A case study of this approach is Elefsis Gulf, a coastal ecosystem in the eastern Mediterranean, located 18 km from the historic city of Athens, Greece.

Impacts of the shipbuilding industry on the ecosystem services and the challenges for a sustainable blue economy: Case study of a coastal ecosystem in the Eastern Mediterranean

Blue Economy includes all economic activities that take place in the ocean, sea and coastal areas. Despite their importance and continuous growth, the blue economy activities have serious impacts on the marine and coastal environment. A sustainable blue economy preserves social cohesion, promotes environmental protection and produces economic growth. Shipbuilding is one of the main blue economy sectors, covering the construction of the cargo, passenger, military and research fleet and its maintenance. The shipbuilding sector is important for the EU economy, in terms of economic development, employment and support of the supply chain. The last years, the shipbuilding and repair industry of Greece is reborn, with a respected number of shipyards to increase their activities. The shipbuilding activities belong to the so called “heavy” industries, creating significant environmental pressures to the coastal ecosystem, that affect a series of ecosystem services. Case study of this research is the Gulf of Elefsis, a vulnerable ecosystem facing the impacts of the industrial activities of shipbuilding and repair, and the environmental problems that occur. The present study is an attempt to spot the ecosystem services that are threatened by the shipbuilding industry and to propose the appropriate measures and responses to face the existing pressures.

Development of a Protocol for a Sustainable Blue Economy in the Coastal Zone: Case Study and Preliminary Results in a Coastal Industrial Area in the Eastern Mediterranean

During the last decade, growing demand has prevailed for environmental protection and the application of sustainability principles toward the coastal environment. As the coastal zone constitutes one of the first recipients of the impacts of climate change due to the rise in sea level, integrated coastal zone management arises as a significant tool for the study of vulnerable coastal ecosystems. In combination with ICZM, the use of indicators and ecosystem services analysis couples all of the information, leading to an integrated approach and opportunities for a sustainable blue economy in coastal ecosystems. The aim of the present study is to form a protocol for a sustainable blue economy in the coastal zone, which will investigate and define the current capacity and the boundaries of a coastal ecosystem with specific characteristics of industrial activity, cultural heritage, and a protected natural environment. The case study for this research is the Gulf of Elefsis, a special sea basin in the eastern Mediterranean, located a short distance from the Athens metropolitan area. The Gulf of Elefsis is characterized by a developed coastal zone, which includes intense industrial activity, the ancient historical sights of Elefsis, the environmentally protected wetland of lake Koumoundourou, the town of Elefsis, a trade port, and growing shipbuilding activity.

Can we document if regulation and Best Available Techniques (BAT) have any positive impact on the marine environment? A case based on a steel mill in Greece.

In order to document the impact of Best Available Techniques (BAT) and implementation of regulation on the improvement of the coastal marine environment state, we examined the case of a representative steel mill located at the Gulf of Elefsis (Greece). The evaluation of metal pollution was based on the analysis of major and trace elements, organic carbon, magnetic properties, and sediment accumulation rates, in sediment cores obtained from the vicinity of the plant. The analytical data are discussed in relation to steel production, changes of production routes, and adoption of BAT introduced in order to fulfill EU and national legislation. The results show that the input of pollutants to sediments and the degree of contamination were reduced by approximately 40-70% in the decade 2003-2015 in comparison to the periods of high discharges (1963-2002), whereas the toxicity risks from "high-to-extremely high" were reduced to "medium-to-high."

Application of ecological risk indicators for the assessment of Greek surficial sediments contaminated by toxic metals.

Τhe present research investigates the partitioning of six selected toxic metals (Ni, Cr, Pb, Zn, Cu, and As) in eight sediment samples; half of them were collected from Elefsis Gulf, and the other half were taken from Koumoundourou Lake, Athens, Greece. Each one of them was treated by applying Tessier's five-step sequential extraction procedure. Regarding gulf sediments, the results indicated that Cu exhibits a strong affinity to the organic matter with percentages ranging from 65 to 78 %. Considerable amount of Zn (32-40 %) is bound to the Fe-Mn fraction and the non-residual fraction, while Cr and Ni are bound to the organic fraction, an observation that suits all toxic metals examined. Regarding lake sediments, Pb is the predominant metal bound to Fe-Mn (48-51 %). It is also noteworthy that the percentage of Zn bound to carbonated fraction (5-15 %), indicating biological availability. In conclusion, the application of several ecological risk indicators demonstrated that Elefsis Gulf sediments correspond to a moderate pollution level, with Pb and Ni being less bioavailable than in the lake's samples, in contrast to Zn which is more bioavailable. Finally, Koumoundourou Lakes' basin is characterized of "low risk."

Linking Environmental Magnetism to Geochemical Studies and Management of Trace Metals. Examples from Fluvial, Estuarine and Marine Systems

Among the diverse research fields and wide range of studies encompassed by environmental magnetism, the present work elaborates on critical aspects of the geochemistry of trace metals that emerged through years of original research in a variety of environmental compartments. This review aims at sharing the insights gained on (a) tracing metal pollution sources; and (b) identifying processes and transport pathways from sources to depositional environments. Case studies on the Elefsis Gulf (Greece) and the Gulf of Lions (France) demonstrate the potential of combined magnetic measurements and chemical analysis to trace pollution signals resulting from land-based sources and atmospheric deposition. Case studies on estuarine environments, namely the Louros, Acheloos, and Asopos Estuaries (Greece), address modes of trace metal behavior under the influence of different hydrological regimes and elucidate in situ processes within the transitional estuarine zone, that define their ultimate fate. As sources, transport pathways, and processes of trace metals are fundamental in environmental management assessments, the involvement of magnetic measurements in the policy cycle could facilitate the development and implementation of appropriate regulatory measures for the integrated management of river basins, coastal, and marine areas.

Bioaccumulation of metals (Cd, Cu, Zn) by the marine bivalves M. galloprovincialis, P. radiata, V. verrucosa and C. chione in Mediterranean coastal microenvironments: association with metal bioavailability

The concentrations of Cd, Cu and Zn in both the whole soft tissue and separate organs (gills, mantle, muscle and digestive gland) of wild bivalves (Mytilus galloprovincialis, Pinctada radiata, Venus verrucosa and Callista chione) from three different coastal microenvironments of Greece were monitored from 2003 to 2004. In parallel, by employing appropriate analytical protocols for metal partitioning, the labile fraction of the metals was determined in the dissolved phase, suspended particulate matter and sediments. Differences in the metal levels were detected both among the study areas as well as among the bivalves examined. Significant bioaccumulation was demonstrated regarding Zn in M. galloprovincialis specimens from the highly industrialized Gulf of Elefsis and Cd in P. radiata and V. verrucosa from the Maliakos Gulf, which is influenced by extended agricultural activity occurring at the neighbouring area and a river outflow. Data of the metal levels in the various environmental phases were correlated with their concentrations in bivalves' tissues. The clear relationships obtained in many cases among the labile metal concentrations and the bioaccumulated concentrations in bivalves point out that the labile fraction of a metal is the most bioavailable. The lack of positive correlation for C. chione confirms the occurrence of effective mechanisms of internal regulation of metal concentrations.

Distribution of trace metals in the sediments of Elefsis Gulf

The present work examines the temporal evolution of industrial contamination in sediments caused by trace metals in the Elefsis Gulf, Greece. The current state of contamination as well as the related sources can be obtained from the study of the sediments. Trace metals, namely Ni, Cu, Fe, and Mn, were collected during 1984-2003 by the local monitoring network. The statistical analysis of the data and the contaminants isopleths patterns support the following conclusions: There is a strong correlation between the nearby coastal industrial activities and the distribution of the trace metals’ concentration in sediments. There is no seasonal or annual variation of the distribution. The sediments’ concentration of Mn in all sampling points and Cu in the center of the Gulf has decreased during the last years.

Speciation studies of copper in the Gulf of Elefsis: the role of the macroalgae Ulva rigida

The Gulf of Elefsis, situated in the vicinity of Athens, is a high productivity area regarding the biota. One of the most abundant algae existing there is Ulva rigida. Controlled laboratory simulation experiments, as well as field investigations indicated that copper is complexed to a high extent with organic substances released by U. rigida and other naturally occurring organic ligands. A significant part of these organic ligands exhibit surface active properties, i.e. the accumulation on different phase boundaries (e.g. seawater/atmosphere, seawater/living organisms, seawater/particulate suspended matter, seawater/sediments). The complexing capacity values of samples collected from different microenvironments within the Gulf of Elefsis, determined by the electrochemical method of differential pulse anodic stripping voltammetry (DPASV), vary between 0.04 and 0.43 μM Cu 2+. At the same time, the complexing capacities of samples obtained from the laboratory tanks in which U. rigida has been placed in order to be decomposed under controlled conditions, show much higher complexing capacity values (up to 13 μM Cu 2+), especially during the final stage of the experiment. The method of linear sweep voltammetry (LSV) was applied for the determination of the concentration of sulfur species (S 0+S 2−) present in nonaerated tanks containing U. rigida. The total concentration of sulfur species in tank No. 2 was 300 nM while in tank No. 3 it was 500 nM. As a result of the presence of sulfur species, a part of the complexing capacity of the substances released during algae biomass decomposition in these two tanks could be attributed to the formation of copper sulfides. Furthermore, the surfactant activity (amount of surface active substances (SAS) expressed in equivalents of the nonionic surfactant Triton-X-100) was determined by A.C. out of phase voltammetry. Higher amounts of SAS were detected in the tanks containing U. rigida (up to 0.70 mg/l eq. T-X-100), in comparison to samples originating from natural microenvironments which had values ranging between 0.10 and 0.17 mg/l eq. T-X-100. These results show that U. rigida, although definitely not the only or necessarily the major contributor to the organic ligand pool in the study area, contributes considerably to the production of ligands with high metal complexing capacity and/or high surfactant activity.

Displacement field and fault model for the September 7, 1999 Athens Earthquake inferred from ERS2 Satellite radar interferometry

On September 7, 1999, a moderate (Mw=5.9) normal faulting earthquake occurred in the northwest of Athens (Hellas) causing heavy damages and casualties. Using interferometric combinations of ERS2 SAR images, we analyzed the coseismic deformation field. Two fringes are observed south of the Fili mountain, up to the coastline of the Elefsis gulf. They correspond to 56 mm increase in slant range. Modeling the earthquake as a dislocation in an elastic half‐space, we inverted the interferometric data to assess the fault location and geometry and the amplitude of the coseismic slip. The model suggests ∼300 mm slip on an 18 km long blind fault composed of two pieces. The intersection of the fault plane with the Earth surface is located in the Fili mountain with a ∼N120° orientation.

Trace metal and magnetic studies of sediments in greek estuaries and enclosed gulfs

Minicores of seabottom sediments from typical coastal and estuarine areas of Greece (the Gulf of Elefsis and the estuaries of the Acheloos and Louros rivers), influenced in a widely varying degree by anthropogenic inputs, were analysed for trace metal content and measured for a series of magnetic properties (i.e., total magnetic susceptibility, frequency dependent susceptibility, isothermal remanent magnetization and demagnetization). Apparent linkages between trace metal content (total or in chemically leached fractions) and magnetic properties were found in cores from all areas. Variations in the relative importance of the non-leachable fraction of metals in the Elefsis Gulf sediments closely parallel changes in the percentage frequency dependent susceptibility, which can be considered as indicator of soil derived material. By combining chemical and magnetic data, very useful information was obtained on: (a) the origin (industrial) of the rapidly deposited sediments in the Gulf of Elefsis; (b) the deposition rate, which was estimated as 0.5 cm per annum; (c) the range and nature of the major natural particle assemblages present in the Acheloos and Louros estuaries; (d) the distinction between the assemblages deriving from the erosion of surface soils and from unweathered parent material; (e) the identification of particles acting as major trace metal carriers (viz. anthropogenic particulates and soil-derived clays). In general the results confirm that integrated trace metal—magnetic studies can provide valuable data on the origin, transport and sedimentation mechanisms of trace metals associated in various ways with particles in coastal and estuarine systems. New perspectives are briefly discussed.

Lead in coastal sediments: The case of the elefsis gulf, Greece

Lead was determined in surface sediments and cores of a typical, polluted, almost enclosed Mediterranean embayment, the Gulf of Elefsis, near Athens. Total lead concentrations of 500–600 μg g −1 were found in the surface sediments of the northeast section of the gulf, near major industries. However, a few kilometers from the source the concentrations decrease to ∼ 40m μg g −1; the background pre-industrial levels are ∼ 10 μg g −1 (in the < 61 μm fraction). Sequential extractions, consideration of the Pb/Al and Pb/Zn ratios, etc., indicate that the upper 5–15 cm of the sediment column are greatly enriched with lead of anthropogenic origin, which is mainly associated with fine particles. Redox reactions play an important role in the distribution and chemistry of lead, most of which (∼ 40%) is associated with organic matter and sulphides (extracted by EDTA); another ∼ 30% is associated with iron and manganese coatings and carbonates, with only a small but significant 3–4% of the total in a readily exchangeable form. The latter, under given conditions, may influence the lead concentrations in the overlying waters.

Particulate pollution monitoring in the Elefsis Gulf: The role of mineral magnetic studies

Measurements of ‘quadrature’ susceptibility ( X q) at low and high frequency on seabottom sediments of the Gulf of Elefsis supplement the results derived from the study of magnetic susceptibility ( X) and saturation isothermal remanent magnetization (SIRM) (Scoullos et al., 1979) and make possible the distinction between the background soil erosional fraction and that of anthropogenic combustion origin. New devices speed up the on-site appraisal of the impact of discharges on marine sediment quality.

Zinc in seawater and sediments of the Gulf of Elefsis, Greece

Dissolved and particulate Zn were measured in the sea water of the small Gulf of Elefsis, near Athens, Greece, for one year and as a function of depth. Particulate Zn was correlated with magnetic properties. Total Zn distribution in surface and subsurface sea bottom sediments and the partitioning of Zn among various sediment fractions were studied on a number of cores. The results for the Gulf of Elefsis are compared to recent results from other areas.

Magnetic monitoring of marine particulate pollution in the Elefsis Gulf, Greece

Measurements of magnetic susceptibility (χ) and saturation isothermal remanent magnetization (SIRM) on both filtered particulates and sediment samples provide a cheap, rapid and non-destructive method of particulate pollution monitoring in marine environments where ferrimagnetic iron oxides are important components of the discharge from industrial or urban complexes. The value of this approach is illustrated by reference to results obtained from the Elefsis Gulf, Greece, where the major source of particulate metal pollution is an iron and steel works discharging waste into a settling lagoon connected to the waters of the Gulf.