Eastern Mediterranean Basin Research Articles

Movement pathways and habitat use of blue sharks (Prionace glauca) in the Western Mediterranean Sea: Distribution in relation to environmental factors, reproductive biology, and conservation issues

The blue shark (Prionace glauca), a highly migratory and wide-ranging shark, has been classified as Critically Endangered in the Mediterranean Sea by the International Union for Conservation of Nature since 2016 due to overfishing. Surprisingly, basic information on its biology and ecology, essential for its conservation, remains unknown, and its regional stock has not been assessed. A multi-year large-scale telemetry tagging programme was implemented to fill these gaps. A total of 39 blue sharks were equipped with satellite tags in three areas of the Western Mediterranean, and their movements and home ranges were examined by sex and size class. Their distributions and habitat preferences across seasons were identified using satellite-based environmental data. Tagged sharks were capable of long-range movement between distant regions, but they did not move neither towards the Eastern Mediterranean basins nor the North Atlantic. We identified the Gulf of Lions as the mating, parturition and nursery grounds. We demonstrated that sharks can use the general geostrophic current system for large movements. Our results support the current stock boundary in the Mediterranean based on international conventional tagging programmes and genetic studies, but the absence of connectivity between the two Mediterranean basins and the North Atlantic basin suggests that they have distinct stocks. Our findings provide critical input for developing effective conservation and management plans for this cosmopolitan species. For the first time in the Mediterranean, this study provides insights into the movement patterns of blue sharks and their habitat preferences.

Polyphenol-enriched extracts of Sarcopoterium spinosum fruits for counteracting lipid accumulation and oxidative stress in an in vitro model of hepatic steatosis

Sarcopoterium spinosum (L.) Spach is a Rosaceae shrub employed in the folk medicine in the Eastern Mediterranean basin. The previous few studies have focused on the S. spinosum roots, while the fruits have been poorly investigated. The present study aims to assess the biological properties of S. spinosum fruits collected in Lebanon and subjected to ethanolic, water or boiling water extraction. The extracts were compared for the phenol and flavonoid contents, and for the in vitro radical scavenging ability. The ethanolic extract (SEE) was selected and characterized by high-performance liquid chromatography coupled with mass spectrometry (HPLC-MS/MS) showing a phenolome rich in tannins (ellagitannins), flavonoids (quercetin derivatives), and triterpenes. The biological activity of SEE was tested on a cellular model of moderate steatosis consisting of lipid-loaded hepatic cells treated with increasing concentrations of SEE (1–25 μg/mL), or with corilagin or quercetin as comparison. In steatotic hepatocytes the SEE was able (i) to ameliorate the hepatosteatosis; (ii) to counteract the excess ROS and lipid peroxidation; (iii) to restore the impaired catalase activity. The results indicate that the ethanolic extract from S. spinosum fruits is endowed with relevant antisteatotic and antioxidant activities and might find application as nutraceutical product.

Terrestrial heat flow and subsidence of the Eastern Mediterranean Sea

We analysed the bathymetry and both marine and continental heat-flow data of the Eastern Mediterranean Sea basins. Bathymetry was corrected for the subsidence caused by sediment deposition to obtain the water-loaded seafloor depth. The thermal measurements were critically reviewed and corrected for sedimentation by 1–13 mW m−2 and for climatic changes by 4–5 mW m−2 to infer the purely conductive terrestrial heat flow. The seafloor depths and thermal data of the Ionian, Herodotus and Levantine basins were compared to reference models of continental lithosphere stretching and ocean plate cooling. In the Levantine Basin, the seafloor depth of 5.0 km argues for a continental crust that thinned ∼100 Ma ago by a factor of 2.7. The seafloor depth of the Herodotus and Ionian basins (7.5 and 6.3 km, respectively) does not match the continental stretching model predictions, suggesting they are floored by oceanic lithosphere. The reference models for the plate cooling and subsidence only partly account for the seafloor depth of the Eastern Mediterranean Sea basins. The seafloor of the Ionian agrees or is slightly deeper than the reference models, while in the Herodotus, it may exceed the expected subsidence of about 1 km. Compared to the reference models of plate cooling, the heat flow of the Herodotus and Ionian basins is lower by about 10 mW m−2. Together with the seafloor depth and gravity anomaly pattern, this argues for a cold and thick lithosphere beneath the Ionian and Herodotus basins. The lower heat flow may suggest that the basins escape from classical schemes of oceanic lithosphere cooling or that the reference models cannot be used for such old seafloors.

Satellite imagery in evaluating oil spill modelling scenarios for the Syrian oil spill crisis, summer 2021

The second-largest oil pollution incident in the Eastern Mediterranean Levantine basin, following the oil pollution crisis in Lebanon in 2006, is considered to be the oil leakage from the Syrian Baniyas power plant (summer 2021), during which 12,000 tons of oil were released. At the operational phase, the everyday predictions of oil drift were provided using the MEDSLIK and MEDSLIK-II models in the framework of an agreement between the Mediterranean Operational Network for Global Ocean Observing System (MONGOOS) and the Regional Marine Pollution Emergency Response Centre for the Mediterranean (REMPEC). In this work, we present a novel post-operational comprehensive model-based analysis, conducting a SAR validation in two model outputs: the MEDSLIK and the OpenDrift models. Each simulation is initiated with the operationally acquired EMSA-CSN and ESA SAR images. Moreover, the high-resolution met-ocean fields (CYCOFOS, SKIRON) are used to force the oil drift and transformation in both models. The spill was developed under the calm-wind conditions that prevailed during the incident. We found that the boundary sea currents developed on the periphery of the Lattakia eddies (anticyclonic and cyclonic) were responsible for the fast westward spreading of the oil spill offshore in the NE Levantine, the north-south pathway bifurcation, and re-landing of oil in the extended coastal area of Lattakia. Model outputs were validated against Synthetic-aperture radar (SAR) images with appropriate performance metrics, used for the first time, to assess the capacity of a reliable representation of oil spill drift. The intercomparison between the two oil spill models indicated that both models produce almost similar results, while their validation against the satellite SAR observations illustrates moderate accuracy.

Factors driving dispersal and habitat use of loggerhead sea turtle post-hatchlings and its conservational implications

Nesting events of loggerhead sea turtles (Caretta caretta) are on the rise in the Western Mediterranean Sea, far from their usual nesting areas in the Mediterranean and Atlantic basins. The study of dispersal behavior toward potential developmental areas of loggerhead post-hatchlings from this new nesting area is crucial to comprehend this colonization process and determining grounded conservation strategies. To fill this gap, we investigated, for the first time in the Mediterranean Sea, the dispersal strategies and habitat use based on data from 19 head-started loggerhead post-hatchlings released from the Spanish Mediterranean coast and satellite-tracked between 2016 and 2018. Turtles dispersed over large areas and showed active swimming phases, as they frequently dispersed against sea currents. Dispersal routes varied for each individual, although they consistently dispersed south-eastwards, especially during the coldest periods. Several post-hatchlings traveled through the Sicilian Channel to reach deep and warmer areas in the eastern Mediterranean basin. The most year-round suitable areas corresponded to the Ionian and Levantine Seas, which correspond with those found in their traditional nesting areas. Therefore, conservation measures focused on this stage should be taken in the path toward and these developmental areas.

Behavioural patterns, spatial utilisation and landings composition of a small-scale fishery in the eastern Mediterranean

Small-scale fisheries (SSFs) are crucial for global food security and cultural heritage, however, information on their spatial distribution and practices are often lacking, precluding effective management and mitigation of ecological impacts. This is acutely the case in the eastern Mediterranean basin, where, despite concerns being raised regarding the magnitude of marine turtle bycatch in SSFs over two decades ago, a poor understanding of the fishery persists. To address this knowledge gap, we characterised the SSF fleet of Northern Cyprus through a combination of onboard observations, fisher self-reporting and vessel tracking to provide the first comprehensive overview of the fishery. Northern Cyprus had a fleet size, standardised by coastline length, ranked 14th of 23 Mediterranean fleets assessed, with an estimated 49542 and 57198 fishing days in total in 2020 and 2021, respectively. Vessels operated mainly over the continental shelf (< 200 m) and were predominantly active during the night (53.2%, n = 573378 locations). Clear crepuscular peaks in vessel activity and gear deployment raise concerns over spatiotemporal overlap with vulnerable species, even within MPAs previously established to protect them. Fishers (n = 1296 fishing operations) predominantly utilised static and demersal gear types including gill nets (35.0%), trammel nets (27.3%), trammel and gill nets combined (20.3%), demersal longlines (17.0%) and handlines (0.5%). Landings composition was highly diverse with a minimum of 238 different taxa identified, including, but not limited to, 123 species of bony fish, 22 elasmobranch species, 3 marine turtle species and 12 mollusc species of which 18.6% are considered threatened either at a Mediterranean or global scale. However, over 70.0% of total landing mass was comprised of only five species including bogue (Boops boops), picarel (Spicara smaris), blotched picarel (Spicara maena), greater amberjack (Seriola dumerili) and Mediterranean parrotfish (Sparisoma cretense). As the most up to date and detailed understanding of this fishery’s operating behaviours, our research compares the results obtained from onboard observer and self-reporting fisher sampling methodologies and discusses the caveats of each and identifies potential opportunities to adapt existing practices and MPAs to improve long-term sustainability of the fishery, whilst maintaining its socio-economic benefits to the local community.

Borrelia persica infection in wild carnivores in Israel: molecular characterization and new potential reservoirs

BackgroundBorrelia persica causes tick-borne relapsing fever in Israel, the eastern Mediterranean basin, and Asia. Relapsing fever is associated with severe illness and potentially death in humans and animals. Since B. persica infection has rarely been described in wild animals, the aim of this study was to evaluate the prevalence of infection with B. persica in wild carnivores in Israel.MethodsSpleen and blood clot samples from wild carnivores, which underwent necropsy, were tested for the presence of Borrelia DNA by real-time polymerase chain reaction (PCR). PCR products were sequenced, and the spirochete loads were quantified using a specific quantitative PCR (qPCR).ResultsA total of 140 samples from 74 wild carnivores were analyzed for the presence of Borrelia DNA. Six out of the 74 (8.1%) animals were found positive for B. persica by PCR and sequencing of the flagellin B gene, of which 4/74 (5.4%) were also positive by PCR for the glycerophosphodiester phosphodiesterase (glpQ) gene. Positive samples were obtained from three European badgers, and one striped hyena, golden jackal, and red fox each. All B. persica-positive animals were young males (P < 0.0001). Quantifiable results were obtained from 3/5 spleen and 4/5 blood samples. The spirochete loads in the blood were significantly higher than those found in the spleen (P = 0.034).ConclusionsThe prevalence of B. persica infection found in wild carnivores brought for necropsy was unexpectedly high, suggesting that this infection is widespread in some wild animal species in Israel. This is the first report of B. persica infection in the European badger and striped hyena. These carnivores have a wide geographical range of activity, and the results of this survey raise the possibility that they may serve as reservoir hosts for B. persica.Graphical

Waterways transformation in the vulnerable port city of Alexandria

The IPCC AR6 report advises that climate change will exacerbate storm surges and coastal flooding in the eastern Mediterranean basin in the upcoming decades. The above is particularly acute in low-lying arid cities in developing nations like Alexandria. The communities' lack of awareness of these rising vulnerabilities subsequently impacts their willingness to tackle upcoming challenges. The latter strongly relies on the public perception and efficiency of the ongoing waterways and waterscape transformations, which remains largely unquantified. To address this deficiency, we evaluate these factors for the historic transformed 21-km canal in Alexandria's vulnerable arid port city. We perform a public survey based on the City Development Strategy for Sustainable Development criterion, assessing the inhabitants' perceptions of the degeneration and transformation of the city's most iconic and historic urban waterway. Our results suggest that the waterscape's multiple transformations negatively influenced the inhabitants' awareness of Alexandria's coastal vulnerabilities and led to public disconnection from the city's maritime heritage, visual attributes, and environment. This disconnection resulting from decades of degrading waterways and inefficient landscape transformations is mainly observed among youth and further compromises the city's resilience to upcoming coastal hazards and aggravates the ecological and coastal degradations. We suggest an adaptive conceptual plan of waterways regeneration to restore their roles in mitigating climatic challenges and improving public connectivity to the historic city's marine identity.

Flood susceptibility mapping with ensemble machine learning: a case of Eastern Mediterranean basin, Türkiye

Flood susceptibility mapping with ensemble machine learning: a case of Eastern Mediterranean basin, Türkiye

Pre-Stack Imaging for the Messinian Sub Salt Sequences in the Levantine Basin of the East Mediterranean: A Case Study, Offshore Lebanon

The Mediterranean Sea has a progressive geological significance; it is considered a vast extensive promising basin for gas exploration. Herodotus and Levantine basins are the main basins in the eastern Mediterranean basin, which are similar in their evolution stages and accommodate similar sedimentary sequences. The recent geophysical and petrophysical studies proved that Herodotus and Levantine basins are promising for gas with possible great reserves exceeding 2,000 bcm. Recent discoveries and increased exploration activities including seismic acquisition and offshore drilling made the Eastern Mediterranean a hot area for gas exploration, especially after the discovery of Zohr gas Field in 2015, offshore Egypt. However, the regional extension of the complex Messinian salt beds and domes make the exploration of high risk. The subsalt seismic imaging in a time domain and the resolution of the underlying carbonate/clastic reservoirs' primary reflections are a big challenge in this area. Therefore, the main objective of the present study is to improve sub-salt imaging with much more accurate interval velocity estimation. In the study area, offshore Lebanon, the delineated structures in the sub-salt imaging after the Pre-stack Depth Imaging were more significant compared to the Pre-Stack Time Imaging which provided optimum sub-salt imaging and enabled the accurate interpretation of the main geologic features which may increase the certainty level of the hydrocarbon exploration and discoveries.

Control of Hercynian Orogeny on basin evolution on the southern margin of the Tethyan region: A review and new insights

The Hercynian Orogeny was caused by the collision of Gondwana and Laurussia in the Mid‐/Late Carboniferous–Early Permian. This orogeny strongly influenced the pattern and evolution of basins and hydrocarbon accumulation on the southern margin of the Tethyan region (i.e., North Africa and the Middle East). Research on the Carboniferous–Early Permian Hercynian Orogeny is of great value in both plate tectonic reconstructions and hydrocarbon exploration. For its influence on basin evolution, some previous studies have considered the modification of the early Palaeozoic basins, but there has been less work on the evolution of the post‐Hercynian Mesozoic basins. We review the available data and re‐analyse the spatiotemporal impacts of this key tectonic event on the evolution of the basins in this region. The Carboniferous–Early Permian Hercynian Orogeny was an important turning point in basin evolution in North Africa and the Middle East. It interrupted the stability of the Gondwana platform and heralded a huge change in the pattern of basins from the uniform pre‐Hercynian Palaeozoic basins to the post‐Hercynian Mesozoic basins characterized by strong segmentation. The Carboniferous–Early Permian Hercynian Orogeny not only modified the pre‐Hercynian Palaeozoic basins but also controlled the distribution and evolution of the post‐Hercynian Mesozoic basins. Large‐scale uplifts were generated among the basins through modification of the inherited palaeohighs and five large NE‐trending arches were newly formed. These uplifts divided the early unified basin into multiple separate basins. Five large‐scale, almost equidistant, NE‐trending arches were generated on the northern margin of Gondwana (the Allala, Sirte, Levant, Al‐Batin and Oman arches), forming the present‐day Palaeozoic Basin pattern with an alternating distribution of uplifts and depressions. The northern part of the large, NE‐trending Hercynian arches collapsed as a result of the extensional stress caused by the opening of the Neotethys Ocean in the Late Permian–Triassic and formed Mesozoic basin depocenters (the Oued Mya–Pelagian basins, the Sirte Basin, the Eastern Mediterranean Basin and the Central Arabian Basin). These depocenters are important oil and gas enrichment zones. The NE‐trending Hercynian arches, the Mesozoic basin depocenters, the opening of the Neotethys Ocean and the segmentation of the basins by the Alpine Orogeny all show relatively consistent east–west‐directed segmentation on the northern margin of Gondwana. This shows that they may have a unified dynamic genetic background. The zone of structural weakness formed by the collision of multiple terranes during the Pan‐African Orogeny may have controlled this segmentation. The inheritance between reformation of the pre‐Hercynian Palaeozoic basins and influence on the post‐Hercynian Mesozoic basins by Carboniferous–Early Permian Hercynian Orogeny, is the result of the tectonics repetitively focused in pre‐existing weaker domains, under the lithospheric mantle modification in the polyphase assembly and break‐up of the supercontinent.

Two new freshwater blennies from the Eastern Mediterranean basin (Teleostei: Blenniidae).

Two new species of Salariopsis are described from the Eastern Mediterranean basin. Salariopsis burcuae, new species, from the Bay of Antalya east to the Jordan, is characterised by having a short cirrus, usually not overlapping the 9th circum-orbital sensory pore, and many tiny black dots on the cheek not organised in rows or bands. The new species shows a 4.1% K2P sequence divergence on the cytochrome-c-oxidase subunit 1 (COI) barcoding region from its closest relative, S. fluviatilis. Salariopsis renatorum, new species, from the upper Ceyhan drainage and a coastal stream in Arsuz, is distinguished by having an unbranched supraocular tentacle, black lateral line pores, a short snout, and no black dots on the upper part of the flank and on the cheek. It is also distinguished from its geographically closest congener, S. burcuae, by a molecular distance of 8.8% K2P in its COI barcode region.

Chloroplast microsatellite diversity of Pinus brutia Ten. and Pinus halepensis Mill. populations across the Mediterranean basin: Inferences of their distributions

Aim of study: To characterize and compare the genetic resources and gain some insights into the evolutionary history of Aleppo pine (Pinus halepensis Mill.) and Brutia pine (Pinus brutia Ten.) species which are both distributed across more than 8 million hectares of area in the Mediterranean Basin.&#x0D; Study area: Fifty-six populations from eight Mediterranean basin countries where P. halepensis and P. brutia species are located.&#x0D; Materials and methods: We analyzed 1344 seeds belonging to 56 populations using five cpSSR primers (Pt15169, Pt30204, Pt41093, Pt87268, and Pt110048).&#x0D; Main results: The analysis of molecular variance (AMOVA) revealed that the genetic diversity among the Brutia pine populations was slightly higher than that of Aleppo pine (27.06% and 24.27%, respectively). The Aleppo pine populations separately displayed a clear east-west differentiation across the Mediterranean Basin, confirming previous results using other markers. Although the Brutia pine populations showed no spatial genetic pattern, geographically close populations and/or populations from their continual distribution range were genetically closer than the fragmented and/or ecologically marginal populations.&#x0D; Research highlights: The seven Aleppo pine populations from the eastern range (Türkiye, Greece, and Italy) were more than two-fold diverse than the 13 populations from the western range (Spain and Morocco). The eastern range of Aleppo pine and Brutia pine populations had similar levels of genetic diversity parameters. These results suggested that the Eastern Mediterranean Basin is a possible genetic diversity center for the two pine species.

Seasonal and interannual variability of Mediterranean Sea overturning circulation

The overturning streamfunction is a widely used metric to monitor ocean circulation changes in the North Atlantic Ocean. Analogously, it is known that an overturning circulation develops in the Mediterranean Sea, although substantially weaker and smaller than in the Atlantic. In this work we use monthly mean fields from a high-resolution ocean reanalysis (1/16°×1/16°) to explore seasonal and interannual variability of Mediterranean Sea overturning circulation in depth and water mass parameter spaces (potential density, potential temperature, salinity) from 1987 to 2018 (both included). Results show a clear single zonal clockwise transport cell in all three spaces that extends from the Strait of Gibraltar to the Levantine Basin, in which water masses tend to densify as they move eastward. This densification is mainly controlled by salinity in the Eastern Mediterranean basin (EMED), while in the Western Mediterranean (WMED) both salinity and potential temperature variations should be taken into account. In contrast, the meridional overturning transport, much more complex, is able to better capture smaller-scale variations since it responds faster to perturbations in the circulation.Seasonal variations in overturning transport are reflected in the size and strength of overturning cells in all spaces, being cells remarkably narrower in winter than in summer. Regarding interannual changes, we show that the meridional overturning transport in density space is significantly correlated with the North Atlantic Oscillation, the Mediterranean Oscillation Index and the Scandinavian pattern during wintertime in the WMED, and with the Eastern Atlantic and the East Atlantic–Western Russian in the EMED. The overturning metric in density space captures well the Eastern Mediterranean Transient, that occurred during years 1992–1996. Finally, we explore the usefulness of overturning metric to detect and track water mass changes associated to shorter scale events, using as example the strong deep convection events of years 2004–2006 in the Gulf of Lion, which marked the beginning of the Western Mediterranean Transition.

Modeling the form, distribution and paleoclimatic implications of former glaciers in the Teke Peninsula (Eastern Mediterranean, Turkey)

The Western Taurus Mountains on the Teke Peninsula, Southwestern Turkey, saw substantial glaciation in the late Quaternary period. Accurate reconstructions of former glacier extent in this relatively marginal area of glaciation are important for establishing the paleoclimate in the Eastern Mediterranean Basin. From west to east, the mountains of Sandıras, Karadağ, Akdağ (Kaş), and Beydağları preserve clear evidence of cirques and moraines, representing glacial valley land systems. This study used calculation tools for Glacier Reconstruction, (GlaRe) and Equilibrium Line Altitude (ELA), with glacier outlines based on the geomorphological evidence and Digital Elevation Models (DEMs), to determine the distribution and ELAs of former glaciers and to estimate paleotemperature and paleo-precipitation during the maximum ice extent. The results are analyzed at three scales: for each glacier, between glaciers and between mountain ranges. While the glaciation was at its peak, we estimate that glaciers covered a total area of 26.4 km2 (1.28 ± 0.08 km2 on Sandıras Mountain, 3.86 ± 0.23 km2 on Karadağ, 16.17 ± 0.970 km2 on Akdağ (Kaş), and 5.09 ± 0.30 km2 in Beydağları): the longest glacier was in Akdağ (Kaş) with a length of 5787 m. Average paleo-ELA (pELA) was calculated as 2077 m a.s.l in Sandıras, 2097 m a.s.l in Karadağ, 2565 m a.s.l in Akdağ (Kaş), and 2468 m a.s.l in Beydağları. Glacier modeling estimated that the maximum ice thickness in Akdağ was 240 m ± 14, and the average thickness 75 ± 4 m. Among these mountains, Karadağ had the lowest elevation to which glaciers descended (1760 ± 16 m a.s.l). Topographic analyses revealed that glaciers formed in the four mountains mostly in the North-facing localities with highest slope values of 18 to 30°. During the maximum glaciation period air temperature depression has been estimated as 8 to 9° Celsius; That required a precipitation increase of some 40 to 60 % compared to present, to produce the former glaciers mapped in the Teke Peninsula.

Seasonal Phenology and Climate Associated Feeding Activity of Introduced Marchalina hellenica in Southeast Australia.

Invasive insects pose an increasing risk to global agriculture, environmental stability, and public health. Giant pine scale (GPS), Marchalina hellenica Gennadius (Hemiptera: Marchalinidae), is a phloem feeding scale insect endemic to the Eastern Mediterranean Basin, where it primarily feeds on Pinus halepensis and other Pinaceae. In 2014, GPS was detected in the southeast of Melbourne, Victoria, Australia, infesting the novel host Pinus radiata. An eradication program was unsuccessful, and with this insect now established within the state, containment and management efforts are underway to stop its spread; however, there remains a need to understand the insect's phenology and behaviour in Australia to better inform control efforts. We documented the annual life cycle and seasonal fluctuations in activity of GPS in Australia over a 32 month period at two contrasting field sites. Onset and duration of life stages were comparable to seasons in Mediterranean conspecifics, although the results imply the timing of GPS life stage progression is broadening or accelerating. GPS density was higher in Australia compared to Mediterranean reports, possibly due to the absence of key natural predators, such as the silver fly, Neoleucopis kartliana Tanasijtshuk (Diptera, Chamaemyiidae). Insect density and honeydew production in the Australian GPS population studied varied among locations and between generations. Although insect activity was well explained by climate, conditions recorded inside infested bark fissures often provided the weakest explanation of GPS activity. Our findings suggest that GPS activity is strongly influenced by climate, and this may in part be related to changes in host quality. An improved understanding of how our changing climate is influencing the phenology of phloem feeding insects such as GPS will help with predictions as to where these insects are likely to flourish and assist with management programs for pest species.

Genomics reveals the role of admixture in the evolution of structure among sperm whale populations within the Mediterranean Sea.

In oceanic ecosystems, the nature of barriers to gene flow and the processes by which populations may become isolated are different from the terrestrial environment, and less well understood. In this study we investigate a highly mobile species (the sperm whale, Physeter macrocephalus) that is genetically differentiated between an open North Atlantic population and the populations in the Mediterranean Sea. We apply high-resolution single nucleotide polymorphism (SNP) analysis to study the nature of barriers to gene flow in this system, assessing the putative boundary into the Mediterranean (Strait of Gibraltar and Alboran Sea region), and including novel analyses on structuring among sperm whale populations within the Mediterranean basin. Our data support a recent founding of the Mediterranean population, around the time of the last glacial maximum, and show concerted historical demographic profiles in both the Atlantic and the Mediterranean. In each region there is evidence for a population decline around the time of the founder event. The largest decline was seen within the Mediterranean Sea where effective population size is substantially lower (especially in the eastern basin). While differentiation is strongest at the Atlantic/Mediterranean boundary, there is also weaker but significant differentiation between the eastern and western basins of the Mediterranean Sea. We propose, however, that the mechanisms are different. While post-founding gene flow was reduced between the Mediterranean and Atlantic populations, within the Mediterranean an important factor differentiating the basins is probably a greater degree of admixture between the western basin and the North Atlantic and some level of isolation between the western and eastern Mediterranean basins. Subdivision within the Mediterranean Sea exacerbates conservation concerns and will require consideration of what distinct impacts may affect populations in the two basins.

Abundance estimates for sperm whales in the Mediterranean Sea from acoustic line-transect surveys

The Mediterranean sub-population of sperm whales is believed to be isolated and is classified as Endangered on the IUCN Red List. Although there is evidence to suggest the population is declining, there is a lack of abundance data. A series of acoustic line-transect surveys were undertaken between 2004 and 2013. In 2004, 3,946km of acoustic effort was conducted in the southern Western Mediterranean basin, resulting in the detection of 159 sperm whales. While in 2007 and 2013, 10,276km of acoustic effort was conducted in the Eastern Mediterranean basin, resulting in the detection of 24 sperm whales. A pooled detection function gave an effective strip half-width of 9.8km. A correction for availability bias was made for each block based on published simulations using data on sperm whale acoustic behaviour: estimates of g(0) were 0.95–0.96. Estimated abundances were: Southern Western Mediterranean Block 634 animals [374–1,077] (95% log-normal confidence interval); Hellenic Trench Block 41 [17–100]; Central Aegean Sea Block 33 [5–203]; Herodotus Rise Block 5 [1–28] and Southern Adriatic Sea Block 2 [0–12]. Estimates for all other blocks were zero. The density of sperm whales in the surveyed Southern Western Mediterranean Block was over 17 times higher than for the surveyed Eastern Mediterranean (2.12 and 0.12 whales per 1,000km² respectively). These results, combined with an acoustic survey of the northern Ionian Sea in 2003 and aerial surveys in the northern Western Mediterranean basin in 2010–11, covered approximately 57% of the likely sperm whale habitat in the Western Mediterranean and 75% in the Eastern Mediterranean. Approximate total estimates of sperm whale abundance in the Western and Eastern Mediterranean basins based on extrapolation to the unsurveyed areas are 1,678 and 164 whales respectively. This gives an estimate for the whole Mediterranean Sea of 1,842 animals.

Wildfire hazard mapping in the eastern Mediterranean landscape

Background Wildfires are a growing threat to many ecosystems, bringing devastation to human safety and health, infrastructure, the environment and wildlife. Aims A thorough understanding of the characteristics determining the susceptibility of an area to wildfires is crucial to prevention and management activities. The work focused on a case study of 13 countries in the eastern Mediterranean and southern Black Sea basins. Methods A data-driven approach was implemented where a decade of past wildfires was linked to geoclimatic and anthropic descriptors via a machine learning classification technique (Random Forest). Empirical classification of fuel allowed linking of fire intensity and hazard to environmental drivers. Key results Wildfire susceptibility, intensity and hazard were obtained for the study area. For the first time, the methodology is applied at a supranational scale characterised by a diverse climate and vegetation landscape, relying on open data. Conclusions This approach successfully allowed identification of the main wildfire drivers and led to identification of areas that are more susceptible to impactful wildfire events. Implications This work demonstrated the feasibility of the proposed framework and settled the basis for its scalability at a supranational level.

Use of different indices to assess the ecological status of lake systems in the eastern mediterranean river basin

The objective of this research was to assess the ecological status of lentic systems in the Eastern Mediterranean River basin (Türkiye) using some biotic (Q index, PT-BV, MedPTI, TDIL, and PTI) and abiotic (WQI, WQImin-nw, TSI, TLI, and Kna) indices. Phytoplankton species such as Peridinium cinctum, Ceratium hirundinella, and Gyrosigma balticum were the species that contributed the most to the algal biovolume of lake systems with different ecological statuses in the basin. According to the results, it was seen that CCA coordination, which analyzed the relationship structures between dominant phytoplankton taxa and environmental water quality parameters, explained the variation sufficiently. As pointed out in the CCA analysis, conductivity and ammonium were the main environmental parameters influencing algal assemblages at sampling sites in the basin (p &lt; 0.01). Strong correlations were observed between TSI and TLI (correlation coefficient: 0.99), and TDIL showed significant correlation only with the Q index (p &lt; 0.01). TSI, TLI and WQI, abiotic indices, indicated significant correlations with most environmental parameters (p &lt; 0.01), while PTI, a biotic index, had weak correlations with most environmental parameters (p &gt; 0.05). Among the indices used in this study, it seems that diatom-based TDIL and physicochemical-based WQI appear to be the most suitable indices for assessing the ecological status of lentic systems in the Mediterranean region. Accordingly, it can be deduced that coupling biotic and abiotic indices is more accurate in determining the water quality of lentic systems.