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The article discusses the study of the flood's dynamics with the use of new formulations based on how rivers change landscapes through incision as modelled by Daniel Garcia-Castellanos and his colleagues in Barcelona, Spain. It mentions the influence of the underlying tectonic process that keeps water in place. It highlights the land bridge between Europe and Africa and the Mediterranean Sea.

The article reports on the investigation of Polychiorobiphenyls and Organochiorine pesticides in tissues of Tuna from the Mediterranean Sea in 1999. Polychlorobiphenyls and organochlorine pesticides are among endocrine disrupting chemicals. They can cause adverse effects in organisms involving disrupting of the endocrine system and the reproduction in wildlife and humans. The Mediterranean Sea is a completely land locked water body which is polluted by extensive anthropogenic activities from industrialized hinterland and so it is particularly exposed by this type of contamination. This research is part of a large monitoring program to measure the levels of contaminants in top marine predators and to develop sensitive biomarkers for estimation of toxicological risk in these species.

The topical issue includes 22 papers on different aspects of meteorology and climatology of the Mediterranean and Black Seas. The papers are grouped into three categories, based on scale analysis of processes, and whether the study is dominantly related to the atmospheric or oceanic phenomenon. The category “Storms, Extremes and Mesoscale Processes” encompasses seven papers, ranging from observation and modelling data analysis of extreme atmospheric (severe winds, hailstorms, waterspout, cyclones) and oceanic (meteotsunamis, surface waves) events, occurring locally, but being connected to wider patterns and processes. The six papers in category “Atmospheric Climate, Variability and Climate Change” contain analyses of long-term observations and climate projection outputs, but also assess atmosphere-ocean-land interactions and cycles, that are important in a climate perspective. The category “Ocean Climate and Variability” includes nine papers, which map ocean processes (sea level variability, circulation, sea surface temperatures, vertical thermal structure, water masses and dense water formation) on a climate timescale, both, in the Mediterranean and Black Sea sub-basins, or taking them as a whole. [ABSTRACT FROM AUTHOR]

We studied the genetic structure of the Mediterranean killifish Aphanius fasciatus. Analysis of the sequence variation in a 372-bp portion of the mitochondrial control region in 623 fish from 27 sampling sites along the species’ distributional range (Tyrrhenian coast, Sardinia, Sicily, Adriatic coast, Malta, Tunisia, and Greece) yielded 120 distinct haplotypes. Most of the haplotypes are unique, and only 15 % are shared among different populations. The high FST value (=0.80) suggests a strong population genetic structuring. The phylogenetic analysis based on Bayesian inference, maximum likelihood and maximum parsimony, and the median-joining network show a sharp separation of the Southeastern Sicilian populations (belonging to the Hyblean region) and of the fluvial Tunisian population of Rio Melah from the others. The Adriatic, the Eastern Sicilian, and the Greek populations are well differentiated, while the group of populations from the Central-Western Mediterranean does not show a clear pattern of differentiation. Our findings indicate that the current genetic structuring of A. fasciatus reflects historical geographical patterns occurring within the Mediterranean basin from the Late Miocene to the Pleistocene. The presence of divergent evolutionary entities in the Hyblean region and the Tunisian Rio Melah supports their inclusion as target areas for the conservation of A. fasciatus. [ABSTRACT FROM AUTHOR]

The potential impact of climate change on port operations and infrastructures has received much less attention than the corresponding impact for beach systems. However, ports have always been vulnerable to weather extremes and climate change could enhance such occurrences at timescales comparable to the design lifetime of harbour engineering structures. The analysis in this paper starts with the main climatic variables affecting harbour engineering and exploitation. It continues with a review of the available projections for such variables first at global scale and then at a regional scale (Catalan coast in the western Mediterranean) as a study case for similar environments in the planet. The detailed assessment of impacts starts from downscaled projections for mean sea level and wave storms (wind not considered in the paper). This is followed by an analysis of the port operations and infrastructure performance that are relevant from a climate perspective. The key climatic factors here considered are relative sea level, wave storm features (height, period, direction and duration) and their combined effect, which is expected to produce the highest impacts. The paper ends with a discussion and some examples of analyses aiming at port adaptation to future climate change. [ABSTRACT FROM AUTHOR]

The current technological developments in autonomous underwater vehicles (AUVs) and underwater communication have nowadays allowed to push the original idea of autonomous ocean sampling network even further, with the possibility of using each agent of the network not only as an operative component driven by external commands (model-driven) but as a reactive element able to act in response to changing conditions as measured during the exploration (data-driven). With this paper, we propose a novel data-driven algorithm for AUVs team for adaptive sampling of oceanic regions, where each agent shares its knowledge of the environment with its teammates and autonomously takes decision in order to reconstruct the desired oceanic field. In particular, sampling point selection is made in order to minimize the uncertainty in the estimated field while keeping communication contact with the rest of the team and avoiding to repeatedly sampling sub-regions already explored. The proposed approach is based on the use of the emergent behaviour technique and on the use of artificial potential functions (interest functions) to achieve the desired goal at the end of the mission. In this way, there is no explicit minimization of a cost functional at each decision step. The oceanic field is reconstructed by the application of radial basis functions interpolation of irregularly spaced data. A simulative example for the estimation of a salinity field with sea data obtained using the Mediterranean Sea Forecasting System is shown in the paper, in order to investigate the effect of the different uncertainty sources, including sea currents, on the behaviour of the exploration team and ultimately on the reconstruction of the salinity field. [ABSTRACT FROM AUTHOR]

The monogenean Microcotyle erythrini is atypical because it has been recorded from several fish host species in the Mediterranean Sea and Atlantic Ocean, in contrast to many species which are considered strictly specific. This could indicate a true lack of specificity or that several cryptic species are involved. This paper is a partial attempt to solve this problem. Specimens of a monogenean resembling M. erythrini were collected from bogues, Boops boops, caught off Algeria. A comparison with published descriptions and with museum specimens of M. erythrini did not yield any clear morphological difference. However, sequences of cytochrome c oxidase subunit I (COI) differed by 16.3% from that of M. erythrini (from GenBank, material collected from the type-host Pagellus erythrinus), indicating that the species was different. The species from B. boops is therefore described here as Microcotyle isyebi n. sp. and differential diagnoses with Microcotyle species from the Mediterranean and from sparids are provided. These results suggest that a molecular re-evaluation of other M. erythrini-like specimens from various fish hosts could reveal the existence of additional parasite biodiversity. [ABSTRACT FROM AUTHOR]

The Rhône basin is one of Europe's major rivers. It stretches from its source in the Swiss Alps through to the Lake Geneva and then down through France to its mouth on the Mediterranean Sea, where its delta constitutes the Camargue Region. It crosses three different 'cantonal' jurisdictions in Switzerland alone, while its course through Lake Geneva itself demarcates the border between France and Switzerland. This presents a valuable opportunity to analyse the multitude of challenges that face the management of a river flowing through such a variety of different hydrological contexts and institutional settings (Swiss, French and European). For the first time, this special issue collates interdisciplinary insights into the challenges faced by the governance systems across the entire Rhône basin. Papers present insights into barriers and opportunities for effectively responding to the many political, economic and climatological challenges facing the managers of the River Rhône over the coming decades. [ABSTRACT FROM AUTHOR]

Cory's shearwater Calonectris diomedea is the main seabird species by-caught by the Spanish longline fleet operating in the western Mediterranean Sea. Identification of the principal factors that determine this by-catch and understanding how they could be controlled is fundamental for improving the management of fisheries and so carry out a better conservation of Cory's shearwater populations in the Mediterranean. The aim of this paper was to model the longline by-catch of Mediterranean Cory's shearwater in the Spanish Mediterranean longline fishery as a function of time of the year, technical characteristics of the fishing operation, and geographical location. We used data recorded by an onboard observer program monitoring commercial longline fisheries. During the 10 years covered in this study, 80 birds were captured in 30 fishing operations out of a total of 2,587 observed fishing sets. We used favourability functions and Random Forest analyses to relate the presence of Cory's shearwater in the by-catch with the explanatory factors. The most explanatory factor in relation to incidence of by-catch was the geographical location (longitude and fishing over the continental shelf) and then the technical characteristics of the fishing operation (number of hooks and fishing during non-working days). Our conclusion is clear, because seabirds are more likely to approach longline vessels when trawlers are not allowed to operate (i.e. non-working days), activity of longliners should be limited to working days, and closing longliners activity during the month of October could reduce greatly reducing seabird bycatch. [ABSTRACT FROM AUTHOR]

One would hypothesize that the Common Fisheries Policy, as the umbrella framework for fisheries management in the EU would have the greatest impact on fishers’ communities across Europe. There are, however, biological, economic, social, and political factors, which vary among fishing communities that can affect how these communities react to changes. This paper explores the links between institutional arrangements and ecological dynamics in two European inshore fisheries socio-ecological systems, using a resilience framework. The Mediterranean small-scale fishers do not seem to have been particularly affected by the Common Fisheries Policy regulations but appear affected by competition with the politically strong recreational fishers and the invasion of the rabbit fish population. The inshore fishers along the East coast of Scotland believe that their interests are not as sufficiently protected as the interests of their offshore counterpart. Decisions and initiatives at global, EU, and sometimes national level, tend to take into account those fisheries sectors which have a national economic importance. A socio-ecological analysis can shift the focus from biological and economic aspects to more sustainable long-term delivery of environmental benefits linked to human wellbeing. [ABSTRACT FROM AUTHOR]

This paper provides an inventory of non-indigenous bryozoan species (NIB) recorded in the Mediterranean Sea. Taking into account previous NIB lists and updated non-indigenous concept, a careful literature review was carried out, reporting data on 33 NIB from 14 Mediterranean countries (Algeria, Croatia, Cyprus, Egypt, France, Greece, Israel, Italy, Lebanon, Malta, Spain, Syria, Tunisia and Turkey). A total of 296 valid records were listed, including 6 yet unpublished. Other 62 records were labelled as uncertain and listed separately, until further analyses on taxonomic identity, non-indigenous status and distribution patterns of the species involved will clarify their status. The countries with the higher numbers of NIB and single records are Lebanon (20 and 78, respectively) and Italy (12 and 112, respectively). The distribution of NIB in the Mediterranean Sea appears scattered and no data are available at all for eight countries. Studies and monitoring efforts on bryozoans in the Mediterranean Sea are not evenly distributed, probably as a consequence of the decrease in number of expert taxonomists and the poor allocation of funds on biodiversity studies. The coordination among Mediterranean countries on standardised sampling methods is needed in order to create a comprehensive baseline knowledge on NIB distribution in the Mediterranean Sea and prioritise taxa and countries that are still poorly investigated. [ABSTRACT FROM AUTHOR]

In this paper the main wave height characteristics in the Mediterranean Sea are studied from both observational and numerical perspectives. The numerical wave model WAM is employed on a high spatial resolution mode and in two different versions, one of which incorporates information for sea surface currents. Altimeter data obtained from all available satellite missions over the area are also utilized. The data sets are analyzed both by conventional statistical measures as well as by advanced techniques provided by a relatively new branch of mathematics, information geometry, in the framework of which the data under study and the distributions that they form are treated as elements of non Euclidean spaces. In this framework, novel ideas for the estimation of the deviations between the observed and modeled values are proposed. [ABSTRACT FROM AUTHOR]

Low-elevation coastal areas and their populations are at risk during and after the appearance of a storm surge event. Coastal flooding as a result of storm surge events is investigated in this paper for a number of areas around the north-eastern (NE) Mediterranean coastal zone (Adriatic, Aegean and north Levantine seas). The sea level rise (SLR) due to storm surge events is examined for the period 2000-2004. Wind data, atmospheric pressure and wave data for this period as well as in situ sea elevation measurements (from stations around the Mediterranean coasts) were used. Potential inundation zones were then identified using a 90-m horizontal resolution digital elevation model (DEM). At these zones, the sea surface elevations were calculated for the study period, using the collected data and a 2D storm surge simulation model (1/10×1/10) output, examining the sea level alteration in specific coastal areas, where in situ measurements are absent and are characterised as 'risky' in inundation areas, due to their topography. In order to determine the level of storm track implication on major SLR incidents, the trajectories of the respective storm events were computed. The aim of this paper is to investigate the major storm surge events that appeared during the study period, identify the major 'risky' costal regions along the north-eastern Mediterranean coast and determine their hazard level due to inundation caused by storm surge phenomena. The combination of the risk level determination of an area and the calculation of sea level alteration is an important tool in terms of predicting and protecting the coastal area from extreme meteorological incidents. [ABSTRACT FROM AUTHOR]

Abstract  Hydromorphological features are crucial in structuring habitats for freshwater organisms. The quantification of these variables is often performed through accurate measuring or detailed estimation, but their assessment is not always feasible for river management purposes. Economic and time constraints often lead to difficulty in creating simple summaries of collected data for practical use. The Lentic–lotic River Descriptor (LRD) was developed to identify the character of a river site in terms of local hydraulic conditions. Information about the presence of flow types, channel substrates, in-stream vegetation, organic debris and artificial features is included in its calculation. The main aim of this paper is to investigate whether the lentic–lotic character of a river site, as summarized with the LRD descriptor, is relevant to aquatic invertebrate communities in nearly natural river sites. Invertebrate data were collected with multi-habitat, proportional sampling and hydromorphological information was gained by applying the CARAVAGGIO method (river habitat survey technique) in the field. The dataset was generated from High or Good ecological status river sites located in Mediterranean areas of Italy. Correspondence Analysis was performed to relate the invertebrate community structure to a set of catchment-scale, reach-scale and chemical environmental variables. The results of the multivariate analysis indicate that LRD provides a persuasive explanation of the most important axis of variation in benthic data. This paper also presents the optimal LRD range for a set of invertebrate taxa, accompanied by a short discussion of their potential use in conservation issues. [ABSTRACT FROM AUTHOR]

In this paper, we use the unstructured grid model SCHISM to simulate the thermohydrodynamics in a chain of baroclinic, interconnected basins. The model shows a good skill in simulating the horizontal circulation and vertical profiles of temperature, salinity, and currents. The magnitude and phases of the seasonal changes of circulation are consistent with earlier observations. Among the mesoscale and subbasin-scale circulation features that are realistically simulated are the anticyclonic coastal eddies, the Sebastopol and Batumi eddies, the Marmara Sea outflow around the southern coast of the Limnos Island, and the pathway of the cold water originating from the shelf. The superiority of the simulations compared to earlier numerical studies is demonstrated with the example of model capabilities to resolve the strait dynamics, gravity currents originating from the straits, high-salinity bottom layer on the shallow shelf, as well as the multiple intrusions from the Bosporus Strait down to 700 m depth. The warm temperature intrusions from the strait produce the warm water mass in the intermediate layers of the Black Sea. One novel result is that the seasonal intensification of circulation affects the interbasin exchange, thus allowing us to formulate the concept of circulation-controlled interbasin exchange. To the best of our knowledge, the present numerical simulations, for the first time, suggest that the sea level in the interior part of the Black Sea can be lower than the sea level in the Marmara Sea and even in some parts of the Aegean Sea. The comparison with observations shows that the timings and magnitude of exchange flows are also realistically simulated, along with the blocking events. The short-term variability of the strait transports is largely controlled by the anomalies of wind. The simulations demonstrate the crucial role of the narrow and shallow strait of Bosporus in separating the two pairs of basins: Aegean-Marmara Seas from one side and Azov-Black Seas from the other side. The straits of Kerch and Dardanelles provide sufficient interbasin connectivity that prevents large phase lags of the sea levels in the neighboring basins. The two-layer flows in the three straits considered here show different dependencies upon the net transport, and the spatial variability of this dependence is also quite pronounced. We show that the blocking of the surface flow can occur at different net transports, thus casting doubt on a previous approach of using simple relationships to prescribe (steady) outflow and inflow. Specific attention is paid to the role of synoptic atmospheric forcing for the basin-wide circulation and redistribution of mass in the Black Sea. An important controlling process is the propagation of coastal waves. One major conclusion from this research is that modeling the individual basins separately could result in large inaccuracies because of the critical importance of the cascading character of these interconnected basins. [ABSTRACT FROM AUTHOR]

In this paper we present a stereo visual odometry system developed for autonomous underwater vehicle localization tasks. The main idea is to make use of only highly reliable data in the estimation process, employing a robust keypoint tracking approach and an effective keyframe selection strategy, so that camera movements are estimated with high accuracy even for long paths. Furthermore, in order to limit the drift error, camera pose estimation is referred to the last keyframe, selected by analyzing the feature temporal flow. The proposed system was tested on the KITTI evaluation framework and on the New Tsukuba stereo dataset to assess its effectiveness on long tracks and different illumination conditions. Results of a live archaeological campaign in the Mediterranean Sea, on an AUV equipped with a stereo camera pair, show that our solution can effectively work in underwater environments. [ABSTRACT FROM AUTHOR]

Sea-level variability in the Mediterranean Sea was investigated by means of in-situ (tide-gauge) and satellite altimetry data over a period spanning two decades (from 1993 to 2012). The paper details the sea-level variations during this time period retrieved from the two data sets. Mean sea-level (MSL) estimates obtained from tide-gauge data showed root mean square differences (RMSDs) in the order of 40-50 % of the variance of the MSL signal estimated from satellite altimetry data, with a dependency on the number and quality of the in-situ data considered. Considering the individual time-series, the results showed that coastal tide-gauge and satellite sea-level signals are comparable, with RMSDs that range between 2.5 and 5 cm and correlation coefficients up to the order of 0.8. A coherence analysis and power spectra comparison showed that two signals have a very similar energetic content at semi-annual temporal scales and below, while a phase drift was observed at higher frequencies. Positive sea-level linear trends for the analysis period were estimated for both the mean sea-level and the coastal stations. From 1993 to 2012, the mean sea-level trend ( $$2.44\pm 0.5$$ mm year $$^{-1}$$ ) was found to be affected by the positive anomalies of 2010 and 2011, which were observed in all the cases analysed and were mainly distributed in the eastern part of the basin. Ensemble empirical mode decomposition showed that these events were related to the processes that have dominant periodicities of $$\sim$$ 10 years, and positive residual sea-level trend were generally observed in both data-sets. In terms of mean sea-level trends, a significant positive sea-level trend ( $$>$$ 95 %) in the Mediterranean Sea was found on the basis of at least 15 years of data. [ABSTRACT FROM AUTHOR]

This paper analyzes the impact of cyclones to the atmospheric components on the Mediterranean Sea Water Budget, namely the cyclones contribution to precipitation and evaporation over the Mediterranean Sea. Three regional simulations were performed with the WRF model for the period 1989-2008. The model was run (1) as a standalone model, (2) coupled with the oceanic model NEMO-MED12 and (3) forced by the smoothed Sea Surface Temperature (SST) fields from the second simulation. Cyclones were tracked in all simulations, and their contribution to the total rainfall and evaporation was quantified. Results show that cyclones are mainly associated with extreme precipitation, representing more than 50 % of the annual rainfall over the Mediterranean Sea. On the other hand, we found that cyclone-induced evaporation represents only a small fraction of the annual total, except in winter, when the most intense Mediterranean cyclones take place. Despite the significant contribution of cyclones to rainfall, our results show that there is a balance between cyclone-induced rainfall and evaporation, suggesting a weak net impact of cyclones on the Mediterranean Sea water budget. The sensitivity of our results with respect to rapid SST changes during the development of cyclones was also investigated. Both rainfall and evaporation are affected in correlation with the SST response to the atmosphere. In fact, air feedbacks to the Mediterranean Sea during the cyclones occurrence were shown to cool down the SST and consequently to reduce rainfall and evaporation at the proximity of cyclone centers. [ABSTRACT FROM AUTHOR]

The present paper provides an overview of mercury studies performed in the Mediterranean Sea region in the framework of several research projects funded by the European Commission and on-going national programmes carried out during the last 15 years. These studies investigated the temporal and spatial distribution of mercury species in air, in the water column and sediments, and the transport mechanisms connecting them. It was found that atmospheric concentrations of Hg compounds, particularly oxidised Hg species observed at five coastal sites in the Mediterranean Sea Basin, are significantly higher compared with those recorded at five coastal sites distributed across N Europe, most probably due to natural emissions. Hg levels in water are comparable to other oceans. Anthropogenic and natural point sources show locally limited enrichments, while natural diffusive sources influence Hg speciation over larger areas. Results and statistic comparison of mercury species concentrations within Mediterranean compartments will be presented and discussed. [ABSTRACT FROM AUTHOR]

Loggerhead turtles nesting in the Mediterranean Sea exhibit remarkable genetic structuring. This paper tests the hypothesis that young loggerhead turtles from different rookeries do not distribute homogeneously among the major Mediterranean foraging grounds, due to a complex pattern of surface currents. We extracted long fragments of mitochondrial DNA from 275 stranded or bycaught juvenile turtles from six foraging grounds (Catalano-Balearic Sea, Algerian basin, Tyrrhenian Sea, Adriatic Sea, northern Ionian Sea and southern Levantine Sea). We used a Bayesian mixed-stock analysis to estimate the contributions from rookeries in the Mediterranean, the North-west Atlantic and Cape Verde to the studied foraging grounds. Differences were found in the relative contribution of juvenile turtles of Atlantic and Mediterranean origin to each foraging ground. A decreasing proportion of Atlantic juveniles was detected along the main surface current entering the Mediterranean, with a high prevalence of turtles from eastern Florida in the Algerian basin and lower numbers elsewhere. In regard to the turtles of Mediterranean origin, juveniles from Libya prevailed in central and western Mediterranean foraging grounds other than the Algerian basin. Conversely, the Adriatic Sea was characterised by a large presence of individuals from western Greece, while the southern Levantine Sea was inhabited by a heterogeneous mix of turtles from the eastern Mediterranean rookeries (Turkey, Lebanon and Israel). Overall, the distribution of juveniles may be related to surface circulation patterns in the Mediterranean and suggests that fisheries might have differential effects on each population depending on the overlap degree between foraging and fishing grounds. [ABSTRACT FROM AUTHOR]

The sea level change is a crucial indicator of our climate. The spatial sampling offered by satellite altimetry and its continuity during the past years are the major assets to provide an improved vision of the Mediterranean sea level changes. In this paper, an automatic signal extraction approach, based on Singular Spectrum Analysis (SSA), is utilized for analysis and seasonal adjustment of the Mediterranean Sea level series. This automatic approach enables us to overcome the difficulties of visual identification of trend constituents that sometimes we encounter when using the conventional SSA method. The results indicate that the Mediterranean mean sea level is dominated by several harmonic components. The annual signal is particularly strong and almost covers 73.62 % of the original sea level series variation whiles its amplitude is about 15 cm. The extracted trend also indicates that the Mediterranean main sea level has significantly been raised during the period 1993-2012 by 2.44 ± 0.4 mm yr. As an important consequence, considering the current situation, if this trend continues, the Mediterranean Sea level will be raised about 22 cm by the end of this century, which makes a dramatic effect on several issues such as land, flora, fauna, and people activities established along the Mediterranean coastlines. [ABSTRACT FROM AUTHOR]

Medicanes, strong mesoscale cyclones with tropical-like features, develop occasionally over the Mediterranean Sea. Due to the scarcity of observations over sea and the coarse resolution of the long-term reanalysis datasets, it is difficult to study systematically the multidecadal statistics of sub-synoptic medicanes. Our goal is to assess the long-term variability and trends of medicanes, obtaining a long-term climatology through dynamical downscaling of the NCEP/NCAR reanalysis data. In this paper, we examine the robustness of this method and investigate the value added for the study of medicanes. To do so, we performed several climate mode simulations with a high resolution regional atmospheric model (CCLM) for a number of test cases described in the literature. We find that the medicanes are formed in the simulations, with deeper pressures and stronger winds than in the driving global NCEP reanalysis. The tracks are adequately reproduced. We conclude that our methodology is suitable for constructing multi-decadal statistics and scenarios of current and possible future medicane activities. [ABSTRACT FROM AUTHOR]

This paper analyzes changes of maximum temperatures in Europe, which are evaluated using two state-of-the-art regional climate models from the EU ENSEMBLES project. Extremes are expressed in terms of return values using a time-dependent generalized extreme value (GEV) model fitted to monthly maxima. Unlike the standard GEV method, this approach allows analyzing return periods at different time scales (monthly, seasonal, annual, etc). The study focuses on the end of the 20th century (1961-2000), used as a calibration/validation period, and assesses the changes projected for the period 2061-2100 considering the A1B emission scenario. The performance of the regional models is evaluated for each season of the calibration period against the high-resolution gridded E-OBS dataset, showing a similar South-North gradient with larger values over the Mediterranean basin. The inter-RCM changes in the bias pattern with respect to the E-OBS are larger than the bias resulting from a change in the boundary conditions from ERA-40 to ECHAM5 20c3m. The maximum temperature response to increased green house gases, as projected by the A1B scenario, is consistent for both RCMs. Under that scenario, results indicate that the increments for extremes (e.g. 40-year return values) will be two or three times higher than those for the mean seasonal temperatures, particularly during Spring and Summer in Southern Europe. [ABSTRACT FROM AUTHOR]

In this paper levels of four (Hg, Cd, Pb, As) potential harmful elements (PHE) were measured in three different environmental matrices (sediments, macroalgae and fishes) from the Aeolian Archipelago and control areas both after 1 and 10 months from a volcanic activity of particular relevance occurred at the end of October 2002. Results were analysed on a multivariate statistical basis with the aim to evaluate: (I) general levels of pollution and increase of PHE due to the event; (II) differences observed among tested matrices in the time of recovery after the occurrence of the critical event; (III) the biological enrichment of PHE along the trophic web produced by the geological event. Results evidenced that volcanic emissions could represent a local source of particular relevance able to determine great enrichments of considered PHE in sediments and biological species. After 10 months from the event, levels in sediments and macroalgae notably decreased, whereas fish species evidenced an increase, principally related to the bioaccumulation phenomena. On the basis of the biological enrichment factors (BEF), major enrichments were evidenced after 1 month whereas, after 10 months, were recorded values reliable to an incomplete recovery. Concerning Cd, the BEF higher levels reported for the species Serranus cabrilla was probably related both to the diet and to the specific detoxification rates of this species. [ABSTRACT FROM AUTHOR]

A new approach to the statistics of rainfall shortage at monthly scale in Western Europe is obtained from precipitation records of 115 gauges over the twentieth century. In this paper, a month is considered to have rainfall deficit when its rain amount is below the 50th percentile of the respective calendar month. The monthly shortage, MS, for every month with deficit is then computed as the absolute value of the difference between its monthly amount and the corresponding truncation level. The cumulative distributions of monthly shortage, CMS, and number of shortage months, CNM, constitute a new description of the monthly rainfall deficit. Both CMS and CNM distributions fit well to a Weibull model. Using the analogy to the normalised daily rainfall curves formulation, NRC, the relationship between CMS and CNM, named as normalised shortage curve, NSC, is modelled by the same function applied to NRCs. Similarly to NRCs, the behaviour of the NSCs strongly depends on the coefficient of variation of the monthly shortage, CV. Four coordinates characterising every NSC are then introduced: the CMS percentile associated with the median of CNM; the CNM percentile related to the median of CMS; and the percentiles of CMS and CNM for the average monthly shortage. In this way, the degree of asymmetric distribution of the monthly deficit is quantified. With the aim of performing a clustering process based on these four coordinates, a principal component analysis, is previously applied to remove redundancies, being obtained two uncorrelated principal components, PCs, characterising every NSC. An average linkage algorithm is then applied to these two PCs, leading to obtain spatially coherent groups of gauges with very similar NSC patterns. This clustering process permits to discard latitude and vicinity to the Atlantic Ocean or the Mediterranean Sea as main factors conditioning the monthly shortage regime. [ABSTRACT FROM AUTHOR]

The European Water Policy introduced the necessity to apply new methodological approaches for the sustainable management of water resources. In the present paper the Driving-Pressure-State-Impact-Response (DPSIR) framework was developed as a methodological tool for the case study of Kalamas River basin (NW Greece). According to the DPSIR approach, it was revealed that the main driving forces, leading to pressures, were the agriculture, the livestock and the numerous point-pollution sources located at the catchment area. Elevated nutrients concentrations (NO-N:0.1-2.6 mg/L, NH-N:0.01-1.29 mg/L, SRP: 0.03-5.76 mg/L) along with high chlorophyll-a values (0.54-6.14 mg/m) highlight river eutrophication. Response actions include elimination of diffuse pollution as well as reduction of the organic load through the optimization of the existed treatment plants. Since several parts of Kalamas River are designated as protected areas, specific measures for protecting biodiversity should be undertaken. [ABSTRACT FROM AUTHOR]

Introduction: Complex organic compounds found in oil and sediments linked with a particular source (such as algae, bacteria or vascular plants) are defined as biomarkers and are useful dating indicators in organic geochemistry. Methods and results: This paper presents the composition of the organic matter (OM) on marine surface sediments from a degraded Tunisian coast analysed by pyrolysis and gas chromatography-mass spectrometry (GC-MS). High total OM contents (0.3-4.2%) were detected with high levels of saturated linear hydrocarbons. The aliphatic lipids had contributed with up to 11.7% of the total OM, and their distribution had consisted of resolved compounds ( n-alkanes and fatty acid (FAs)) and an unresolved complex mixture. Hydrocarbons, primarily n-alkanes, were ranged from 368 to 3,886 μg g. The FAs (674-2,568 μg g) were dominated by derived primary production, and the short chain FAs (C16 and C18) were the most abundant throughout. The ubiquitous presence of petroleum contamination, mainly from offshore oil exploration, discharge of pollutants from rivers, shipping activities and atmospheric deposition was found in all samples. The Gabès littoral seems to be quite to very polluted near the industrial zone of Ghannouch. The C/H ratio (generally around 5.9), the thermal analysis and GC-MS of n-alkanes and FAs showed that the OM in the studied area was composed of anthropogenic/petrogenic, marine and continental sources. Conclusions: Our study represents an innovative approach to assessing environmental pollution. The evaluation of organic matter by examination of sterols, alkanes and fatty acids allows the identification of source, both anthropogenic and natural. [ABSTRACT FROM AUTHOR]

Coastal mesoscale eddies were evidenced during a high-frequency radar campaign in the Gulf of Lions (GoL), northwestern Mediterranean Sea, from June 2005 to January 2007. These anticyclonic eddies are characterized by repeated and intermittent occurrences as well as variable lifetime. This paper aims at studying the link between these new surface observations with similar structures suggested at depth by traditional acoustic Doppler current profiler measurements and investigates the eddy generation and driving mechanisms by means of an academic numerical study. The influence of the wind forcing on the GoL circulation and the eddy generation is analyzed, using a number of idealized configurations in order to investigate the interaction with river discharge, buoyancy, and bathymetric effects. The wind forcing is shown to be crucial for two different generation mechanisms: A strong northerly offshore wind (Mistral) generates a vortex column due to the bathymetric constraint of a geostrophic barotropic current, which can surface after the wind relaxes; a southerly onshore wind generates a freshwater bulge from the Rhône river discharge, which detaches from the coast and forms a well-defined surface anticyclonic eddy based on buoyancy gradients. These structures are expected to have important consequences in terms of dispersion or retention of biogeochemical material at local scales. [ABSTRACT FROM AUTHOR]

The present study is aimed at determining the confidence limits of design wave parameters derived from numerical modeling-for both extremes and operational conditions-over the Central and Western Mediterranean Sea. The paper presents the methodology and results of an extensive validation activity conducted on a chain of medium-resolution third-generation wave models used for hindcast purposes. The stringent requirements of state-of-the-art coastal and offshore engineering applications over this area make the adoption of medium- or high-resolution hindcast wave and wind models almost mandatory because of the complex coastal geometry, bathymetry, and orography that in turn lead to large variations of the design wave parameters even within small regions. The chains of nested meteorological and wave models used in this hindcast study belong to the ETA and WaveWatch III families, respectively. In this study the wind and wave numerical models have been run over the past 20 years, with increasing resolutions of the wave models from 0.2° up to 0.04°. The results presented herein have 0.1° resolution for both wind and wave models. The wave data obtained are compared with available measurements from 14 wave buoys in coastal zones in the Central and Western Mediterranean Sea. [ABSTRACT FROM AUTHOR]

The continental shelf and the upper slope of the Gulf of Palermo (Southern Tyrrhenian Sea) in the depth interval ranging from 50 to 1,500 m were mapped for the first time with Multi Beam echosounder and high resolution seismic. Seven submarine canyons are confined to the upper slope or indent the shelf-edge and enter the Palermo intraslope basin at a depth of around 1,300 m. The canyons evolved through concurrent top-down turbiditic processes and bottom-up retrogressive mass failures. Most of the mass failure features of the area are related to canyon-shaping processes and only few of them are not confined to the upper slope. In general, these features probably do not represent a significant tsunami hazard along the coast. The geological element that controls the evolution of the canyons and induces sediment instability corresponds to the steep slope gradient, especially in the western sector of the Gulf, where the steepest canyons are located. The structural features mapped in the Palermo offshore contributed to the regulation of mass failure processes in the area, with direct faults and antiform structures coinciding with some of the canyon heads. Furthermore, the occurrence of pockmarks and highs that probably consist of authigenic carbonates above faulted and folded strata suggests a local relationship between structural control, fluid escape processes and mass failure. This paper presents a valuable high-resolution morphologic dataset of the Gulf of Palermo, which constitutes a reliable base for evaluating the geo-hazard potential related to slope failure in the area. [ABSTRACT FROM AUTHOR]

In the past two decades, optical properties of chromophoric dissolved organic matter (CDOM) in marine environments have been extensively studied. Many of these studies report CDOM properties for the offshore environment where this complex mixture of optically active compounds is strongly diluted. Nevertheless, autochthonous and allochthonous sources have been identified and sinks related to photodegradation and bacterial activity have been demonstrated. The calculation of the spectral slope of the CDOM absorption curve has been proven to be useful and is often reported. However, a rigorous uncertainty analysis of the slope calculation is rarely reported. In this paper, we propose a method to evaluate the uncertainty of CDOM spectral slope calculated between 270 and 400 nm, using both naturally sampled and artificial solutions. We use these results to study the ultra-oligotrophic waters of the Mediterranean Sea (central eastern basin), where little is known about CDOM spatial distribution. We show that dilutions of both artificial and natural samples produce a Gaussian distribution of spectral slopes, indicating that consistent values may be determined, with a typical uncertainty of ±0.0004 nm when absorption at 300 nm was greater then 0.1 m (0.1 m pathlength). Comparing the distribution of spectral slopes from central eastern basin samples to a Gaussian distribution, we show differences between measurements that were significantly different. These values allow us to distinguish possible sources (algal derived CDOM), sinks (e.g. photo-bleaching) at different depths. We propose a subdivision of CDOM compounds into refractory and semilabile/refractory pools and evaluate the CDOM spectral slope of algal derived CDOM released at or near deep chlorophyll maximum. [ABSTRACT FROM AUTHOR]

Salinas systems are artificial wetlands which are interesting from the viewpoint of nature conservation. They play an important role both as habitats for migratory waterbird species and as nodes of biotic connectivity networks. In the Mediterranean basin, where the coastal salinas are highly significant as alternative and complementary habitats for waterbirds, a process of abandonment occurs, and many seminatural systems of this kind are disappearing. This abandonment is having serious consequences for migratory bird populations and for the ecological role these play. In the present paper, this group of waterbird species has been used to evaluate these wetlands for conservation purposes. We have developed a methodological approach for the selection of ecological indicators for the conservation and management of these Mediterranean habitats and waterbird assemblages, the main consumers therein. The stepwise procedure developed constitutes a practical tool for this task. Application thereof enabled us to differentiate the habitats available for the waterbirds and to identify the biotic and abiotic indicators for the maintenance and management of the salina ecosystems. These variables can then be incorporated into monitoring programs. [ABSTRACT FROM AUTHOR]

This paper reviews the gear parameters responsible for loggerhead sea turtle ( Caretta caretta) capture and mortality while taking into account the mitigation measures tested in the Mediterranean Sea. Incidental catch is considered as one of the major threats for turtle survival; however, the loggerhead bycatch estimated in different areas seems to be unrealistic, which highlights the need of a method for homogenising the estimates. Drifting longlines and bottom trawls have the greatest impact on Mediterranean turtle populations, respectively in pelagic and demersal phase, while passive nets (gillnets and trammel nets) seem to be responsible for the highest direct mortality, due to drowning. Most of the experiments available for the Mediterranean are focused on drifting longline. The longline parameters, hook shape and size, bait type, setting position and the reaction to sensory stimuli, strongly affect the sea turtle bycatch and mortality. Circle hooks have the potential to reduce turtle mortality only in certain fisheries and areas; larger hooks are less likely to be swallowed by turtles due to physical constraints of the mouth, reducing the mortality rate and the catch of juveniles; branchlines, once ingested, appear to be one of the major causes of sea turtle mortality; squid bait, which consistently catches more turtles than mackerel, and lightsticks, which strongly attract turtles, should be banned, at least in some areas and seasons. On the contrary only two bottom trawl studies are available from the Mediterranean. Turtle excluder devices have been tested with promising results in Turkey and Italy, even if the loss of large fish should be carefully investigated. For set nets no practical solutions are available at this time. The analysis allows the conclusion that technical parameters affecting turtle bycatch and mortality should only be studied one at a time, in order to avoid inconclusive results, studies on post-release mortality should be implemented and finally fishermen cooperation is paramount in reducing turtle bycatch and mortality. [ABSTRACT FROM AUTHOR]

Unloaded natural rock masses are known to generate seismic signals (G reen et al., ; H ainzl et al., ; H usen et al., ; K raft et al., ). Following a 1,000 m3 mass failure into the Mediterranean Sea, centimeter-wide tensile cracks were observed to have developed on top of an unstable segment of the coastal cliff. Nanoseismic monitoring techniques (W ust-B loch and J oswig, ; J oswig, ), which function as a seismic microscope for extremely weak seismic events, were applied to verify whether brittle failure is still generated within this unconsolidated sandstone mass and to determine whether it can be detected. Sixteen days after the initial mass failure, three small-aperture sparse arrays (Seismic Navigation Systems-SNS) were deployed on top of this 40-m high shoreline cliff. This paper analyzes dozens of spiky nanoseismic (−2.2 ≥ ML ≥ −3.4) signals recorded over one night in continuous mode (at 200 Hz) at very short slant distances (3–67 m). Waveform characterization by sonogram analysis (J oswig, ) shows that these spiky signals are all short in duration (>0.5 s). Most of their signal energy is concentrated in the 10–75 Hz frequency range and the waveforms display high signal similarity. The detection threshold of the data set reaches ML −3.4 at 15 m and ML −2.7 at 67 m. The spatial distribution of source signals shows 3-D clustering within 10 m from the cliff edge. The time distribution of ML magnitude does not display any decay pattern of ML over time. This corroborates an unusual event decay over time (modified Omori’s law), whereby an initial quiet period is followed by regained activity, which then fades again. The polarization of maximal waveform amplitude was used to estimate spatial stress distribution. The orientation of ellipses displaying maximal signal energy is consistent with that of tensile cracks observed in the field and agrees with rock mechanics predictions. The ML– surface rupture length relationship displayed by our data fits a constant-slope extrapolation of empirical data collected by W ells and C oppersmith () for normal fault features at much larger scale. Signal characterization and location as well as the absence of direct anthropogenic noise sources near the monitoring site, all indicate that these nanoseismic signals are generated by brittle failure within the top section of the cliff. The atypical event decay over time that was observed suggests that the cliff material is undergoing post-collapse bulk strain accommodation. This feasibility study demonstrates the potential of nanoseismic monitoring in rapidly detecting, locating and analyzing brittle failure generated within unconsolidated material before total collapse occurs. [ABSTRACT FROM AUTHOR]

The aim of this paper is to propose an approach for optimal siting of the KM3NeT neutrino telescope on the sea floor. The method is based on Geographic Information System (GIS) spatial analyses and cost assessment. GIS techniques initially aim to derive depth and slope characteristics of the sea floor, and estimate the distance from shore. Subsequently, GIS methods are used to pre-select sites meeting the KM3NeT infrastructure criteria. Finally, the candidate locations are evaluated in terms of cost estimation. A convex combination of instantaneous cost functions (ICFs) is applied and different weighting factors are allowed to account for dissimilar importance of the considered variables. The ICFs are indexed by a parameter β to assign different cost characteristics to different variables. The overall assessment is based on the comparison of costs computed for the candidate sites assuming many configurations of weights and β values. Our exercise uses a simulated numerical bathymetry to avoid a site-specific evaluation at the initial stage of the KM3NeT project. Hence, no recommendations as to the real locations of the neutrino telescope in the Mediterranean Sea are addressed. Our approach is found to serve well in the process of comparing costs between different candidate sites. [ABSTRACT FROM AUTHOR]

This paper presents the first record of two native Mediterranean cymothoid species caught attached to introduced Lessepsian rabbitfishes. This is also the first record of cymothoids from the coastal waters of Libya. Anilocra physodes was collected from Siganus luridus while Nerocila bivittata was found on both Siganus rivulatus and S. luridus. Rabbitfishes in the southern central Mediterranean have acquired native Mediterranean cymothoids but do not seem to be infested along the Levantine coast. [ABSTRACT FROM AUTHOR]

Abstract  The Mediterranean Sea is a relatively deep, closed sea with high rates of fisheries exploitation. In recent years fishing activity has tended to shift towards deeper depths. At the same time, the Mediterranean displays some rather special hydrographic and biogeographic conditions. The present paper reviews the present state of knowledge of the fisheries, biology, and ecology of the deep-sea fish and crustacean species in the Mediterranean dwelling below 1,000 m with potential economic interest, placing special emphasis on the western basin, for which more data are available, as a basis for future studies of the ecology, biodiversity, and effects of climate change and exploitation in this zone. This review reveals that mediterranean deep-sea fishes and crustaceans employ highly conservative ecological strategies, and hence the low fecundity and low metabolic rates in a stable environment like the deep-sea make these populations highly vulnerable. Moreover, ripe females of the main species mentioned here concentrate in the deepest portions of their distribution ranges. Deep-sea fish and crustaceans have high trophic levels and low to medium omnivory index values. The ecological indices discussed here, in combination with the limited knowledge of deep-sea ecosystems, clearly call for an approach based on the Precautionary Principle. [ABSTRACT FROM AUTHOR]

The aim of this paper was (1) to update sponge diversity and distribution in the Mediterranean and (2) to re-examine faunal relationships among the Mediterranean areas on the basis of their sponge fauna. The Mediterranean demosponge faunal list was updated to 629 species by taking into consideration recent data from previously poorly studied areas. The species lists of 14 Mediterranean areas were compared on the basis of their sponge species richness, species composition, and taxonomic relatedness of species using multivariate analyses and diversity measures, such as PD, Delta+, and Lambda+. The 14 Mediterranean areas examined for their diversity and affinities were assembled into four major zoogeographic groups: the northwestern, northeastern, the central zone, and southeastern areas. Richest in species numbers were the areas belonging to the two northern groups. The species richness comparisons and similarity analyses performed at the generic level showed that it can be safely used as a surrogate for sponge species diversity in the Mediterranean. The results of this study showed that the simple traditional division of the Mediterranean Sea into a western, central, and eastern basin cannot reliably describe the distribution of sponges in the area. Thus, the W to E faunal decline previously presented for several faunal groups shifts to a general NNW-SSE pattern when one examines separately the northern and the southern parts of the traditional basins. This gradient seems to be in agreement with differences in key environmental variables, such as latitude, salinity, temperature, and water circulation, besides the typically examined distance from Gibraltar. [ABSTRACT FROM AUTHOR]

In 2008, Burlando et al. proposed a two-stage clustering technique for the classification of mesoscale wind regimes. The first stage of this classification scheme is based on a hierarchical cluster analysis, according to Ward’s minimum variance technique applied to an Euclidean distance, for a first-guess subdivision of the events into groups. In the second stage, a partitional k-means clustering for the optimal reassignment of the events among clusters is performed. Following this methodology, in the present paper, the synoptic-scale wind fields over the Mediterranean Sea have been analysed in order to check the suitability of this technique to a higher-dimensional phase space. The study is based on a 30-year-long data set of wind speed and direction at 10 m above sea level obtained from the reanalysis of the European Centre for Medium-range Weather Forecasts. The cluster analysis has been performed on wind speeds only, while wind directions have been used to show the existence, in the spatial structure of the wind climate regimes, of particular regions which correspond to the main topographic and/or thermal forcing of the Mediterranean. These regions are the peaks of the probability density function in the climatological phase space of wind speed patterns recognised by the clustering algorithm. The final classification has been able to identify, for instance, the surface circulation patterns corresponding to Mistral events in the western Mediterranean sub-basin and Etesian winds in the eastern sub-basin. [ABSTRACT FROM AUTHOR]

The paper couples the results obtained by applying the expert and the rapid Macrophyte Quality Indices set up to assess the ecological status of the Italian transitional environments according to the requirements by the Water Framework Directive (2000/60/CE). The indices were validated by comparing the composition of the macrophyte assemblages and the values of some bio-physico-chemical parameters of the water column of 20 stations of the Venice lagoon sampled monthly for one year between 2003 and 2005. In 5 stations out of the 20, the ones which fall within the 5 classes of ecological status suggested by the Water Framework Directive, sedimentation rates, sediment grain-size, and nutrient and pollutant (metals, Polychloro-Dibenzo-Dioxins/Furans, Polycyclic Aromatic Hydrocarbons, Pesticides and Polychlorinated Biphenils) concentrations in surface sediments were also determined. Results showed strong relationships between the trends of these environmental parameters and the composition and structure of macrophyte associations, as well as with the Macrophyte Quality Index assessment. Chlorophyceae showed a trend opposite to Rhodophyceae whose presence was concentrated in oxygenated and transparent environments. Chlorophyceae and the species characterised by low scores prevailed in turbid areas where nutrient and pollutant concentrations were high. Results allowed the identification of the conditions of the “reference sites” (confinement areas and sites with high water renewal) and the integration of the dichotomic key used for the application of the R-MaQI. [ABSTRACT FROM AUTHOR]

Swordfish catch per unit effort (CPUE) data from the Greek commercial fisheries operating in the eastern Mediterranean have been modeled on a seasonal basis as functions of environmental spatial, and temporal variables, including Sea Surface Temperature (SST), Chlorophyll-a (Chl-a), Mean Sea Level Anomaly (MSLA), Latitude, Longitude and Year. All variables were highly significant but most of the CPUE variation was explained by the spatial factors. Model predictions were used to generate swordfish density distributions maps, which revealed that swordfish migrates toward the eastern Levantine for spawning and suggested the existence of a major spawning ground in a region between the islands of Cyprus and Rhodes surrounded by persistent eddies and the Rhodes gyre. During periods other than the time of spawning migration, swordfish distribution is much broader with relatively higher concentrations occurring in areas with important prey potential. [ABSTRACT FROM AUTHOR]

Data on sexual reproduction of scleractinian coral species living in temperate zones, particularly in the Mediterranean Sea, are quite scarce. This paper describes sexual reproduction of the colonial coral Cladocora caespitosa from Veliko jezero (Mljet Island) in the Adriatic Sea. Spawned orange eggs and white sperm bundles were observed on the coral bank of C. caespitosa two nights before the full moon (20 June 2005) coinciding with increasing water temperature and correlated with the lunar cycle. Spawning was observed during five nights, involving about 30% of the colonies from the coral bank. Different colonies on the bank released only one type of gamete during the reproductive period. The diameter of the sperm bundles ranged from 100 to 200 μm (average 163 μm; SD = 47.08), while the female gametes diameter ranged from 300 to 500 μm (average 416 μm; SD = 73.12). [ABSTRACT FROM AUTHOR]

The opening of the Suez Canal resulted in the introduction of Indo-Pacific organisms (Lessepsian) to the eastern Mediterranean. Available information on the Levantine ichthyofauna concerns mainly necto-benthic species, while pelagic ones remain mostly uncharacterized. This paper presents a preliminary assessment of biodiversity and its temporal changes on the Lebanese coast (eastern Mediterranean) using species composition and abundance of pelagic communities as indicators. For this purpose, a total of 11,192 fishes, representing 32 species and 19 families were collected with purse seines. Lessepsian species represented 40. 9% of the species number in the purse-seine catches but only 0. 48% in abundance of individuals and 1. 57% in biomass. The families most represented in terms of abundance were the Clupeidae (49. 28%), the Engraulidae (41. 69%) and the Scombridae (7. 01%); in terms of biomass these families represented 56. 76, 22. 04 and 9. 72%, respectively. Abundance and biomass exhibited clear temporal fluctuations with Sardina pilchardus and Scomber japonicus dominating the catches between May and June, and then replaced by Sardinella aurita in July and Engraulis encrasicolus in August. The highest values of species richness (12 species) and diversity indices ( H′ = 1. 37; D = 0. 71) were recorded in the last two weeks of June while the lowest values (5 species, H′ = 0. 26; D = 0. 11) were recorded in early August. While Lessepsian fishes represented a minor part in terms of landings, they contributed considerably to the diversity of pelagic fish assemblages in Lebanese waters. [ABSTRACT FROM AUTHOR]

Present-day Mediterranean marine biodiversity is undergoing rapid alteration. Because of the increased occurrence of warm-water biota, it has been said that the Mediterranean is under a process of ‘tropicalization’. This paper analyses the main patterns of the Mediterranean Sea tropicalization and considers briefly its extent and consequences. As happened during previous interglacial phases of the Quaternary, Atlantic water, entering via the Straits of Gibraltar, carries into the Mediterranean species that are prevalently of (sub)tropical affinity. On the other side of the basin, Red Sea species penetrate through the Suez Canal, a phenomenon called lessepsian migration from the name of F. De Lesseps, the French engineer who promoted the cutting of the Canal. Also the many exotic species introduced by humans voluntarily or involuntarily are nearly always typical of warm waters. Climate change combines with Atlantic influx, lessepsian migration and the introduction of exotic species by humans to the establishment of tropical marine biota in the Mediterranean Sea. Present-day warming ultimately favours the spread of warm-water species through direct and indirect effects, and especially by changing water circulation. It is impossible at present to foresee to what extent the exuberance of warm-water species will affect the trophic web and the functioning of marine ecosystems in the Mediterranean Sea of tomorrow. While Mediterranean Sea communities are modifying their pattern of species composition, they do not seem to be acquiring a more marked tropical physiognomy: Mediterranean coastal marine ecosystems are still dominated by frondose algae (even if the species that are gaining ascendancy are of tropical origin) and not by corals as is normal in tropical seas. [ABSTRACT FROM AUTHOR]

A total of 310 individuals (124 males, 185 females, 1 indeterminate) of the octopodOctopus salutiicaught throughout the year by bottom trawlers from 25 to 800 m depth in the western Mediterranean were analysed to study some general aspects of its biology. Octopus sizes ranged from 4.0 to 13.0 cm ML and 3.5 to 16.5 cm ML in males and females, respectively. The species inhabits the lower continental shelf and upper slope, primarily between 250 and 500 m depth. The scarcity of small-sized individuals in the samples and the predominance of males and females>8 and>9 cm ML, respectively, suggest two interpretations: (1) juveniles inhabit grounds inaccessible to, or unsampled by, trawlers, or they avoid capture owing to behavioural aspects; or (2) the species meet in the trawling grounds for reproduction, because in the sizes described the majority of individuals have begun sexual maturation. The reproductive period was found to occur during spring and summer. The stomach content analysis revealed a diet composed of 33 different prey items belonging to three major taxonomic groups (crustaceans, fishes and cephalopods). Quantitatively, crustaceans (Decapoda Reptantia and Natantia groups) were the most important prey, appearing in 87% of the stomachs, followed by fish (25%) and cephalopods (10%). Finally, the paper presents data on mantle length-total weight, gonad weight-total weight and ligulae length-total weight relationships, and utilises different indexes (gonadosomatic, hepatosomatic, fullness weight and emptiness) to describe changes through the three maturity stages of both sexes. [ABSTRACT FROM AUTHOR]

This paper considers the potential role of the crinoidLeptometra phalangiumas an indicator of highly productive areas along the shelf break that can sustain large biomasses of benthopelagic fish and recruits. The structure of fish assemblages in the central Mediterranean Sea (central-western coast of Italy), analysed on the basis of surveys carried out in summer and autumn from 1997 to 2001, revealed the presence of a well-defined group of species on the shelf break. This area, occurring at a depth of between 120 and 170 m, is characterised by detritic organogenic sediments colonised by the crinoidL.phalangium, a suspension-feeding macro-epibenthic species confined in the Mediterranean to the shelf-break area. Its abundance in the studied area can reach 12-15 ind. m-2. A total of 121 species belonging to 66 families of demersal organisms (crustacean decapods and stomatopods, cephalopods, selaceens and teleosteens) were caught at shelf-break stations from September to October. The species which typified the assemblage were the fishesTrisopterus minutus capelanus,Merluccius merluccius,Glossanodon leioglossus,Argentina sphyraena,Capros aper,Macroramphos scolopaxandLepidotrigla cavillone, the crustacean decapodParapenaeus longirostrisand the cephalopodsIllex coindetiiandTodaropsis eblanae. Detritic shelf-break stations showed a higher abundance of demersal organisms than stations distributed on muddy bottoms in the same depth range (100-200 m). Such differences appeared to be significant in September-October, when a clear increase in benthopelagic zooplanktivorus species, such asGlossanodon leioglossus,Trachurus trachurus,Trachurus picturatus, was found. The length structure of species occurring on the shelf break showed that for some of them the selection of this area is related to specific phases of their life cycle. Significant highest abundance of recruits and juveniles was observed forMerluccius merluccius,Helicolenus dactylopterus,Phycis blennoides,Parapenaeus longirostrisandCapros aperin at least one of the two seasons. Similarly, an increased abundance of spawners of red mulletMullus barbatusand four-spotted megrimLepidorhombus bosciiwas observed on the shelf break. Results of this study may have important consequences for management of fish stocks and assemblages in the central Mediterranean. The co-occurrence of high densities ofL.phalangiumand benthopelagic fish, occurring mainly with juveniles and spawners, strongly indicates a potential role ofL.phalangiumas an indicator of highly productive areas around the shelf break. Such areas appear to play a major role in the production of some of the most abundant and commercially important fish species, such as the Mediterranean hake and red mullet. [ABSTRACT FROM AUTHOR]

The paper describes the habitat utilization of small cryptobenthic fishes of the families Blenniidae (Lipophrys nigriceps, and Parablennius zvonimiri), Gobiesocidae (Apletodon incognitus, Gouania wildenowi, Lepadogaster candollei, and L. lepadogaster), Gobiidae (Chromogobius zebratus, Corcyrogobius liechtensteini, Didogobius splechtnai, Gammogobius steinitzi, Millerigobius macrocephalus, Thorogobius ephippiatus, T. macrolepis, and Zebrus zebrus), and Tripterygiidae (Tripterygion melanurus). Nine different habitats from the waterline to a depth of about 40 m were examined. The depth distributions of the single species and co-occurrences with other cryptobenthic fish species are given. [ABSTRACT FROM AUTHOR]

In this paper some statistical characteristics of air temperature variations over the Mediterranean are presented. The study is based on temperature data at stations in Marseille (1851-1985), Rome (1851-1985), Athens (1858-1985), and Jerusalem (1864-1985). First the homogeneity of temperature data for each station is examined by means of the short-cut Bartlett test. In another step, the existence of abrupt climatic changes towards warm or cold periods at all stations, with the exception of Athens is pointed out. Some statistical significant persistence of the annual and seasonal time series is also shown. Finally, the temperature fluctuations are examined and discussed in respect to possible causes where particularly the role of the Mediterranean Sea and the topography is considered. [ABSTRACT FROM AUTHOR]

The Mediterranean Region has a long lasting legacy of mercury mining activities and a high density of sub-marine volcanoes that has strongly contributed to its mercury budget. In the last forty years, there have been recorded increases in mercury concentrations in biota that have spurred a growing number of research activities to assess the impact of mercury pollution on human health and environment. Field investigations that quantify mercury concentrations in marine biota have led to a large amount of experimental data scattered in many peer-reviewed publications making it difficult for modelling applications and regional environmental assessments. This paper reviews existing peer-reviewed literature and datasets on mercury concentration in marine flora and fauna (Animal, Plants and Chromista Kingdoms) in the Mediterranean basin. A total of 24,465 records have been retrieved from 539 sources and included in Mercury in Mediterranean Biota (M2B). Well-defined specimens account for 24,407 observations, while a few records include generic plankton and unidentified fish species. Among all considered species, we selected Diplodus sargus, Sardina pilchardus, Thunnus thynnus and Xiphias gladius to show trends of mercury concentration against WHO and EU limits. Few notes on how M2B is intended to support the implementation of the Minamata Convention on Mercury by a user-driven Knowledge Hub are finally reported. Measurement(s) mercury Technology Type(s) digital curation Factor Type(s) geographic location • fishing area • species • sampling time • depth • weight • tissue Sample Characteristic - Organism Eukaryota Sample Characteristic - Environment ocean biome Sample Characteristic - Location Mediterranean Sea • Black Sea Machine-accessible metadata file describing the reported data: 10.6084/m9.figshare.9886004 [ABSTRACT FROM AUTHOR]

The statistical techniques based on compositional data are applied to investigate the evolution of the traffic share of the container throughput in a multi-port system. Compositional vectors are those which contain relative information of parts of some whole. The application of conventional statistical techniques to compositional data may lead to erroneous conclusions and spurious correlations. Therefore, compositional data (CoDa) should be treated taking into account their own mathematical structure. The so-called log-ratio approach provides a set of transformations that allow to apply conventional statistical techniques to the transformed compositional data samples. Thus, the objective of this paper is double. As a first stage it aims to introduce the CoDa formalism and highlight its potentiality in the port container throughput analysis as example of transport system providing an applied example: the container throughput evolution in the Spanish Mediterranean Ports system during the period 1976-2015. Second, based on the previous analysis, the aim is to characterize the container throughput in SpanishMed ports and its temporal evolution. The CoDa analysis clarifies the interpretation and data association of the container traffic throughput evolution in function of some selected change points: boom of containerization in 1990s and 2008 crisis. This contribution proves that the CoDa methodology is useful to investigate the complexity of the transport disciplines in order to understand and to manage the spatial integration that results from the movement of people and freight. [ABSTRACT FROM AUTHOR]