Mediterranean Coastal Zone Research Articles

Long-Term Trends in Significant Wave Heights in The Mediterranean as an Indicator of Climate Change

The Mediterranean coastal zones, particularly along the Nile Delta, are increasingly vulnerable to the impacts of climate change. This study examines the historical changes in the significant wave height along the Nile Delta coast over the past 84 years (1940-2023) at a depth of 20 meters. By synthesizing a comprehensive long-term wave data series using ERA5 reanalysis data and the MIKE21-SW model, the study establishes a robust foundation for analysis. To ensure accuracy, the observed wind data were contrasted against ERA5 data, and they were found to be similar to a great extent. Furthermore, the model's accuracy was rigorously validated against the observational data, ensuring the reliability of the results. Three methods were used to obtain the trends for the maximum wave height to ensure robust and reliable trend assessments (i.e., linear regression, Theil-Sen, and ElasticNet). The results were obtained and analyzed, revealing a statistically significant increase in the maximum wave heights during the study period. Particularly, seasonal analysis revealed a positive trend in maximum wave heights during winter and spring (0.15 to 0.67 cm/year respectively). Furthermore, the monthly analysis showed a positive trend in the wave heights for all months except July, August, and September. Specifically, there were notable increases from September to December, ranging from 0.24 to 0.92 cm/year. These findings are consistent with the global trends of increasing wave heights due to climate change. It is essential for developing adaptive coastal management strategies and designing resilient structures. Consequently, the results will assist coastal authorities in mitigating the impacts of climate change on coastal zones.

Assessment of Trace Metal Contamination in Bivalve, Mytilus galloprovincialis, By Bioconcentration Factor (BCF) in the Moroccan Mediterranean Coast Environment

This study investigates the pollution of Morocco’s Mediterranean coastal zones by trace metals, highlighting its significance due to detrimental impacts on marine ecosystems and potential health risks through the food chain, exacerbated by the expansion of coastal areas in recent years. It focuses on measuring concentrations of trace metals such as copper, cadmium, lead, and chromium in the bivalve Mytilus galloprovincialis and surrounding seawater across three sites along the northern Moroccan Mediterranean coast. This research aims to evaluate metal bioaccumulation levels using the Biota Concentration Factor (BCF). Seawater samples were examined using both flame and graphite furnace atomic absorption spectrophotometry, while bivalve tissue samples underwent analysis through Inductively Coupled Plasma Optical Emission Spectrometry. Findings indicate that M. galloprovincialis significantly accumulates trace metals, with concentrations in descending order: Pb, Zn, Cr, Cu, and Cd. Conversely, the seawater metal concentration sequence was Zn, Cu, Cr, Cd, and Pb. The study applied BCF thresholds from Regulation (EC) No 1907/2006 (REACH) and the US EPA’s Toxic Substances Control Act (TSCA), categorizing metals as “bioaccumulative” (BCF between 1000 and 5000) and “very bioaccumulative” (BCF over 5000). This distribution provides insights into the toxicity and bioaccumulation of metals, underscoring the environmental and health implications for the marine ecosystem and species like M. galloprovincialis.

Impact of drainage effluents and wind direction on the copper distribution and balance in Abu-Qir Bay, Alexandria, Egypt

Heavy metals entering seawater pose a global threat to marine life and the ecological system. In this regard, this study investigates the mass balance of copper in Abu Qir Bay, a shallow basin located in the western Mediterranean coastal zone of Egypt. The study area is well-thought-out as a fertile marine habitat, which emphasizes the presence of naturogenic and anthropogenic activities. Three land-based sources, namely al-Tabia outfall, al-Maadia outlet, and the Rosetta branch of the Nile River, are seriously affecting the bay causing pollution problems. As part of this research, rainfall, seawater, and drainage water samples were collected to determine and evaluate the relative importance of different sources on the geochemical cycle of copper in the bay. The results revealed that the mean total concentration of copper in the bay was 74.61 ± 18.37 μg/l. Abu Qir Bay receives about 1374.8 ± 171.05 and 643.13 ± 153.03 tons of copper annually from agricultural and industrial discharges, respectively. The outflowing surface water from the bay transports 2463 ton/year of the total amount of copper to the southeastern Mediterranean water. The calculated residence time of copper in Abu Qir Bay was 101 days, while the assimilative factor of copper in the bay amounted to 40 ton.m3/mg.year. As per the findings, a 90 % reduction of the total copper concentration in the bay, in case the external loading stops, can act as an important solution for quick recovery of the bay condition to reach 7.5 μg/l after 121 days.

A New Look to the Heletz–Ashdod Oil Field (Southern Israel): A Non-Conventional Hydrocarbon Deposit in the Easternmost Mediterranean

Heletz–Ashdod oil field is the first oil deposit to have been discovered in the Eastern Mediterranean. This deposit has been exploited until the present despite its small reserves. However, this area’s tectonic–geodynamic and structural features must be studied more. Based on the integrated regional geological–geophysical analysis, it was proposed that the Heletz terrane, which includes this deposit, is the nodal structure of the Eastern Mediterranean. This terrane is a composite part of the earlier identified Mesozoic terrane belt (MTB). The Heletz terrane’s essential tectonic peculiarity is the MTB’s impact, rotating counterclockwise. Analysis of local geophysical data in this area (gravity, magnetic, and seismic) and regional thermal data examination testifies to the complex mosaic composition of the Heletz structure. It is proved that the crystal basement below the Heletz terrane is characterized by specific properties that do not coincide with the adjacent areas. Finally, a series of structural–paleogeographic and thickness formation maps of the Heletz–Ashdod oil field has been compiled. This investigation shed light on this area’s perspectives and searched other hydrocarbon deposits in the easternmost Mediterranean coastal and shelf zones.

The impact of climate change on the storm surges of the Mediterranean Sea: Coastal sea level responses to deep depression atmospheric systems

The impact of climate change on the storm surges of the Mediterranean Sea: Coastal sea level responses to deep depression atmospheric systems

Severity gradient of anthropogenic activities along the Egyptian Western Mediterranean coast, utilizing benthic Foraminifera as bio-indicators

Three locations along the western Mediterranean coastal zone of Egypt (Abu Qir Bay, El Max Bay, and Marsa Matrouh), have been exposed to different anthropogenic sources that threatened the benthic ecosystem conditions. Benthic foraminiferal assemblages revealed the environmental changes and highlighted the main factors controlling foraminiferal distribution in the different environments. The assessment of benthic foraminiferal assemblages using quantitative univariate (diversity indices) and multivariate statistical analyses, allied with water quality and sediments geochemical data sets have been verified from a total of 26 surface sediment samples collected along the three locations. Benthic foraminiferal species were abundant in all samples where 51 species, pertaining to 28 genera, have been identified. Abu Qir area reflected a stressful environment with high organic matters and relatively low oxygen levels, followed by El Max Bay. These results revealed that benthic foraminifera favored environments with high organic matter, while benthic ecosystem oxygenation level seems to have a minor impact. The minimum anthropogenic influence over Marsa Matrouh area, compared with the other two sites, was evident from the dominance of sensitive species relative to water quality deviations and narrow pollution tolerance assemblage. Anthropogenic activities along the three selected sites demonstrated a wide range of severity ranging from severe to moderate to insignificant impact over the benthic ecosystem.

Marine Seagrasses Transplantation in Confined and Coastal Adriatic Environments: Methods and Results

The anthropogenic pressures of the twentieth century have seriously endangered the Mediterranean coastal zone; as a consequence, marine seagrass habitats have strongly retreated, mostly those of Posidonia oceanica. For this reason, over time, restoration programs have been put in place through transplantation activities, with different success. These actions have also been conducted with other Mediterranean marine seagrasses. The results of numerous transplanting operations conducted in the Northern Adriatic Sea and lagoons with Cymodocea nodosa, Zostera marina and Z. noltei and in the Central and Southern Adriatic Sea with P. oceanica (only within the project Interreg SASPAS), are herein presented and compared, taking also into account the presence of extensive meadows of C. nodosa, Z. marina and Z. noltei, along the North Adriatic coasts and lagoons.

The Mechanisms of Neolithisation of Western Europe: Beyond a South/North Approach

AbstractUp until now, the neolithisation of Western Europe during the sixth millennium BCE has mainly been approached through the characterisation of its diffusion vectors (cultural vs demic diffusion) and the emergence of technoeconomic innovations (rhythms, scenarios, and transmission). Traditionally, two primary routes of agricultural diffusion are distinguished: one extending along the Danube river corridor to the Atlantic coast (Linearbandkeramik) and the other along the Mediterranean coastal zone (Impressed Ware). To move beyond this dichotomy, this article proposes a first attempt at an integrated approach to the mechanisms of neolithisation in Western Europe, one of the few territories where it is possible, and therefore necessary, to investigate the processes that are common to both of these principal neolithisation complexes. The most widely held vision, inherited from the 1980s, of a European Neolithic that developed from east to west following a regular rhythm has progressively been replaced by a more complex model of diffusion characterised by arrhythmia and cultural reconfigurations. Despite having different origins and trajectories, the expansion of the first farmers was made possible by a number of common mechanisms.Impresso-CardialandLinearbandkeramiksocieties faced similar constraints, especially with regard to ensuring the stability of their social and economic models, while minimising the risks inherent to the colonisation of new territories. Three main mechanisms would have structured the first neolithisation phases of both spheres: a strong mobility of populations regulated to varying degrees by social rules, a strong solidarity expressed at multiple levels of interactions within each sphere, and, finally, the existence of syncretism and cultural recompositions including close and long-distance relations.

Classifying compound coastal storm and heavy rainfall events in the north-western Spanish Mediterranean

Abstract. The north-west (NW) Mediterranean coastal zone is a populous and well-developed area in which the impact of natural hazards like flash floods and coastal storms can result in frequent and significant damages. Although the occurrence and impacts of such hazards have been widely covered, few studies have considered their combined impact on the region, which would result in more damage. Within this context, this study analyses the occurrence and characteristics of compound extreme events of heavy rainfall episodes (as a proxy for flash floods) and coastal storms (using the maximum significant wave height) along the Catalan coast as a paradigm of the NW Mediterranean. Two different types of events are considered: multivariate, in which the two hazards occur at the same location, and spatially compounding, in which they occur within the same limited time window, and their impacts accumulate at distinct and separate locations. The analysis is regionally performed along a coastline extension of about 600 km by considering seven coastal sectors and their corresponding river catchment basins. Once the compound events are analysed, the synoptic atmospheric pressure fields are analysed to determine the prevailing weather conditions that generated them. Finally, a Bayesian network is used to fully characterize these events over the territory. The obtained results show that the NW Mediterranean, represented by the Catalan coast, has a high probability of experiencing compound extreme events. Despite the relatively small size of the study area, there are significant variations in the event characteristics along the territory, with the most frequent type being spatially compound, except in the northernmost sectors where multivariate events dominate. These northern sectors also present the highest correlation in the intensity of both hazards. Three representative synoptic situations have been identified as dominant for the occurrence of these events, with different relative importance levels of the compounding drivers (rainfall and waves) and different distributions of impacts across coastal basins. Overall, results obtained from specific events indicated that heavy rainfall is related to the most significant impacts despite having a larger spatial reach.

Stability of the Northern coast of Egypt under the effect of urbanization and climate change

ABSTRACT The effect of the human activities on the coastal area are enormous. They include impacts on natural resources, coastal stability, environmental quality, and the cultural environment. The instability condition is the predominant feature of the Egyptian coastal zone due to natural and anthropogenic effect. This paper discusses the stability conditions of the sediment within the Egyptian Mediterranean coastal zone. It includes the sediment sources, degradation of resources, reasons and side effects, climate change effects, and recommendations to control the degradation. The research methodology depends on collecting and discussing the results of the previous related studies, collecting field data and observation along the Egyptian Mediterranean coastal zone as well as Satellite images within the last ten years. Sediment origin from territorial or sea resources, sediment transport, and interaction within the coastal zone are investigated to understand the sediment behavior and how to control erosion and siltation problems. The study shows that urbanization, coastal structures, removing sand dunes, controlling the floodwater and sediment, as well as climate change cause severe shoreline changes within the coastal zone. Dramatically erosion along the Northern coast of Egypt, and migration of the sand spit inland along the Rosetta Nile branch document these unbalance conditions. The study recommends that the coastal sand dune, as well as other nature resources of sediment, should be protected to eliminate the coastal erosion.

The effectiveness of setback zones for adapting to sea-level rise in Croatia

The Mediterranean coastal zone is particularly vulnerable to climate-induced sea-level rise due to rapid coastal development, leading to increased flood exposure in coastal areas. In Croatia, the share of developed coastline is still lower than in other Mediterranean countries, but development has accelerated since the 1960s. Available assessments of future coastal flood risk take into account adaptation by hard structural protection measures but do not consider other options, such as retreat from exposed areas or restricting future development. In this study, we provide the first assessment of the effects of setback zones on future coastal flood impacts on national scale. We extend the flood impact and adaptation module of the DIVA modelling framework with models of restricted future development and slow retreat (managed realignment) in the form of setback zones. We apply this model to a downscaled database of coastal segments of the coastline of Croatia. We find that setback zones are an effective and efficient measure for coastal adaptation. Construction restriction and managed realignment reduce the future cost of coastal flooding significantly, especially in combination with protection. If protection and construction restriction by setback zones are combined, the future cost of coastal flooding can be reduced by up to 39%. Combining protection and managed realignment by setback zones can reduce the future cost of coastal flooding by up to 93%.

Selective top-down control of epiphytic biomass by amphipods from Posidonia oceanica meadows: implications for ecosystem functioning

Mediterranean Posidonia oceanica meadows shelter an important biomass and biodiversity of amphipod crustaceans that graze on epiphytes. However, their actual significance for ecosystem functional processes is hard to estimate, due to the lack of adequate data. Here, a field microcosm-based inclusion experiment was used to test if three of the dominant taxa of the amphipod community (Apherusa chiereghinii, Dexamine spiniventris and Gammarus spp.) could exert top-down control on seagrass leaf epiphytes. Influence of amphipod activity on nutrient availability for the host species was also investigated. All grazer taxa significantly reduced biomasses of erect macroalgae and erect sessile animals present on leaves. None of them consumed encrusting epiflora or epifauna. This selective top-down control could have important implications for the structure of the epiphytic community on leaves of P. oceanica, which is one of the most diverse and abundant of all seagrass species. Grazing activity of all taxa caused higher N content of seagrass leaves, likely through amphipod excretion and/or sloppy feeding. Since P. oceanica meadows often grow in oligotrophic zones where plant growth can be nutrient-limited, this N enrichment could enhance seagrass production. Overall, the ecological interaction between P. oceanica and amphipods could be seen as a facultative mutualistic relationship. Our results suggest that amphipod mesograzers are key-elements in some of the functional processes regulating these complex and yet endangered ecosystems, which are essential components of Mediterranean coastal zones.

Landslide susceptibility mapping of the Mediterranean coastal zone of Morocco between Oued Laou and El Jebha using artificial neural networks (ANN)

The goal of this study was to experiment artificial neural network (ANN) classifier on various available physical factors in the study area to produce a reliable landslide susceptibility map. The mapping of landsides is classically established through the identification and analysis of hillslope instability factors. Even if a variety of approaches use these analyses with geographic information system (GIS) performances to carry out a good result, there is no satisfaction because of the complexity of the landslides encountered in the field. In the present study, landslide susceptibility models were produced by using multilayer perceptron (MLP) ANN in the Mediterranean Rif coastal zone of Morocco. This was established in the following steps: (i) production of landslide inventory map; (ii) production of the hillslope factors, twenty factors composed of geology, geomorphometry, proximity, and thematic data derived from satellite imageries; (iii) extraction of vector model to be used to train ANN, construction of ANN models; (iv) validation and evaluation of results. The results of the prediction models were evaluated by the receiver operating characteristic (ROC) curves. The obtained area under the curve (AUC) values are greater than 0.90, indicating that the models are quite accurate. The visual comparisons between landslide susceptibility maps and the input factor maps show that roads and geology are the most important factors influencing five types of mass movements (complex, slide, flow, and rockfall). The success of this work will be helpful to expand this method to the whole Rif mountains in Morocco.

Connecting research infrastructures, scientific and sectorial networks to support integrated management of Mediterranean coastal and rural areas

Many Mediterranean coastal areas encounter similar problems and gaps between science, governance, and implementation of sustainable management at local-regional scales. There is often a lack of coordination between management of inland and coastal areas, and a lack of integrated land-sea data and knowledge exchange to support transitions towards sustainable development and synergies between rural and coastal areas. In this paper, we illustrate the main challenges to reach a sustainable development of coastal-rural areas related to data availability, knowledge exchange and governance, which could be tackled by coupling regional and international research infrastructures (RIs) with scientific and stakeholder collaboration networks to facilitate knowledge exchange and co-creation of solutions. We first identified the main challenges in sustainable development of coastal-rural areas followed by a review of major existing RIs, scientific knowledge and collaboration networks that can help support integrated management of Mediterranean coastal zones. Based on this, we developed recommendations for a better integration of RIs and collaboration networks in the management of coastal-rural areas, including (1) the creation of local networks to facilitate periodical meetings between all sectors involved and to connect science and policy actors and (2) setting up local RIs that support the data processing and the use of regional and international RIs by scientists and policy stakeholders.

Changes in Copepod Community Between Two Contrasting Samplings in a Highly Polluted Mediterranean Coastal Zone (Sfax Bay, Tunisia)

Changes of taxonomic composition, morphology (total length) and reproductive mode of copepod assemblages between the cold and warm periods were studied in the Southern coast of Sfax, in relation with environmental factors and pollution degree (heavy metal concentration). Salinity, temperature and heavy metal concentration seem to be the most important factors influencing the total length during both sampling periods. A total of 23 different copepod species were identified during the survey period. The copepod abundance was higher in cold (74%; 9.78 ± 10.04 A— 103 ind m-3) than in warm (67%; 7.11 ± 8.81 A— 103 ind m-3) periods. This result could be attributed to an increase of temperature and salinity in August, which favors the development of smaller copepod species. During the cold season, larger adult broadcaster of calanoids species (total length between 0.98 and 1.22 mm) such as Acartia (Acartia) danae (Giesbrecht) (Tl = 1.22 mm), Paracartia grani (Sars) (Tl = 1.12 mm) and Paracartia latisetosa (Krichagin) (Tl = 1.06 mm) were associated to low temperature and salinity. During the warm period, smaller egg-carrying species of harpacticoids (total length between 0.18 and 0.3 mm) such as Harpacticus littoralis (Sars), Tisbe furcata (Baird) and Tigriopus sp. (Norman) were associated with high temperature and heavy metal pollution. H. littoralis displayed a very high abundance of ovigerous females (Nfo = 12.8 A— 103 ind m-3, representing 87.2% of total number of females) with high number of eggs per sac (E = 26 ± 2 egg sac-1).

Geospatial Auto-correlation Statistical Analysis to Evaluate the Seismic Magnitudes and Its Implications on the Mediterranean Coastal Zone of Egypt

Geospatial Auto-correlation Statistical Analysis to Evaluate the Seismic Magnitudes and Its Implications on the Mediterranean Coastal Zone of Egypt

STABILITY ANALYSES FOR DOUBLE CROPPING IN SOYBEAN [(Glycine max L.) Merrill

Double crop agriculture is a great advantage for the coastal Mediterranean climate. Although a number of soybean varieties have been recommended for cultivation, the information on the stability for double cropping is lacking for the agro-climatic conditions of Mediterranean coastal zone. Ten high-yielding advanced soybean [Glycine max (L.) Merr] lines and four registered soybean varieties having maturity group III and IV (ARISOY, ATAEM7, BRAVO and NOVA) were evaluated for double cropping in different regions and years (2014, 2015 and 2016 in Izmir-Bornova, 2015 and 2016 in Antalya-Aksu). The F test was first applied to check differences of the deviation variances from the zero. In addition, statistics of ecovalance (Wi2 ) and stability variance (σi2 ), estimating the contribution of a genotype to total Genotype x Environmental interaction (GxE), were estimated. As a result of this research, two different conclusions were determined. If sufficient water is provide (500-700 mm) BATEM 306 and BATEM 317 lines can be grown, otherwise, the other two (BATEM 207 and BATEM 223) can be suitable to grow in the regional conditions.

A framework to analyse urban sprawl in the French Mediterranean coastal zone

As in many other European countries, urbanisation and urban sprawl along the French Mediterranean coast are a major concern. Understanding this phenomenon requires both multi-level and multi-disciplinary approaches. In this perspective, this article presents a framework for the observation and analysis of urban sprawl in the French Mediterranean coastal zone. Developed in the context of a scientific coastal observatory with four contrasting study sites, the framework was designed to structure the observation and analysis of urban sprawl dynamics and their driver variables. Although urban expansion is currently slowing in coastal zones, local exceptions can be found and accounted for by historical urban planning and environmental protection measures, local residential tax policies and contradictory perceptions of coastal zones by residents. Our multi-disciplinary initiative is capable of integrating different temporal and spatial scales and has proven relevant in analysing urban sprawl in coastal areas. It shows the need to study coastal areas at finer scales to identify specific dynamics in their local contexts, since these represent the scale at which administrative decisions are made.

Groundwater condition based on geoelectrical technique and Dar Zarrouk parameters between El Alamein and El Dabaa—Egypt

El Alamein-El-Dabaa area lies in the western Mediterranean coastal zone of Egypt with about 50 km long. The aims of the present study are the shallow groundwater aquifer determination and calculate the electric parameters of the overburden to achieve the easiest way for detecting groundwater contamination and considered it during the planning of new development project(s). To attain this target, 44 vertical resistivity soundings using Schlumberger array of the maximum AB/2 = 1000 m in the form of four profiles were carried out. From the interpretation results, six geoelectrical layers have been established in the area, and iso-resistivity, depth to water, and isopach contour maps are presented. Four geoelectrical cross-sections (two geoelectrical cross-sections are parallel to the Mediterranean shoreline and the other two are normal to the Mediterranean shoreline) have been constructed. According to this work, the upper part of the Oolitic Limestone represents the shallow groundwater aquifer in this area and can be distinguished into two zones. The upper zone is brackish, whereas the lower one is saline. The geoelectrical succession reveals that the aquifer is free type. The depth to water ranges between 20 and 63 m; therefore, it is the choice as the best sites for groundwater exploitation. In the area under study, the depth to water and the thickness of the brackish increase towards the south side as well as the depth to the brackish water. The Dar-Zarrouk parameters clarified that there are some parts that may contaminate pathways and other parts are not.

Natural ventilation potential of the Mediterranean coastal region of Catalonia

Most of the Catalonian population and urban areas are located along the Mediterranean coastal zone and for this analysis three largest Catalonia's cities are chosen: Barcelona, Terrassa and Tarragona. Each city is a geographical representative of a different climate type according to the re-analysed Köppen–Geiger climate classification. The objective of this research is to demonstrate the effects of regional climate variations on the potential of natural ventilation (NV) application in building design. The first part of the article presents the availability of NV corresponding to yearly climate conditions applying the methodology “Climate potential for natural ventilation” (CPNV). In the continuation, the second analysis is calculated with building energy simulation software and displays possible refrigeration energy savings in three geographical locations. Mixed-mode (or hybrid-mode) and night-ventilation techniques are applied for the cooling process of a hypothetical low-rise office building model.