Search Results (311)

Understanding population connectivity and genetic structure is crucial for the effective management of exploited marine species. This study investigates the population genetics of the common European squid (Loligo vulgaris) across the Mediterranean Sea, focusing on samples from the Aegean Sea and comparative sequences from Western Mediterranean, Eastern Mediterranean, and Atlantic coasts. A total of 67 COI mitochondrial sequences were analyzed, identifying 12 haplotypes and 27 polymorphic sites. Population-level genetic diversity, pairwise F_ST values, and haplotype network analyses revealed pronounced genetic differentiation in the eastern Mediterranean contrasting with the genetic homogeneity observed among Western populations. The low haplotype diversity observed in the Greek populations of L. vulgaris may be influenced by a combination of ecological and historical factors, as the Aegean region is recognized as a hotspot of endemism and historical population fragmentation. The results indicate the existence of at least two genetically differentiated clusters within the Mediterranean basin. This study advances current knowledge of the genetic structure of Loligo vulgaris by providing novel genetic data on populations from the eastern Mediterranean, offering valuable insights for future conservation and management strategies for the species. Full article

Although marine caves are among the most species-diverse habitats in the Mediterranean Sea, most available studies have focused on their sessile fauna. This study provides the first quantitative assessment of motile fauna in 27 marine caves across four geographical subareas of the Aegean and Ionian Seas, using a rapid assessment visual census protocol, applied through 3 min time transects in each ecological cave zone. Multivariate analysis revealed that the motile community structure of the cave entrance was differentiated from that of the semidark and dark zones. Deeper caves were distinct from shallower ones while caves of the east Aegean differed from those around Crete Island. A total of 163 taxa were recorded, 27 of which are reported herein for the first time in marine caves of the eastern Mediterranean Sea, while three species (two native and one introduced) are recorded in Greek waters for the first time, enriching our knowledge on the permanent and occasional cave residents. Seventeen species were introduced, comprising more than half of the total fish abundance in the southeasternmost cave. Our limited knowledge of the motile fauna of Mediterranean marine caves coupled with the continued spread of introduced species highlights the urgent need for monitoring and conservation actions, especially within marine protected areas. Full article

The pepper weevil Anthonomus eugenii is a devastating pest native to Central America that can cause severe damage to over 35 pepper varieties. Global trade in peppers has significantly increased the risk of its spread and expansion. Moreover, future climate change may add more uncertainty to its distribution, resulting in considerable ecological and economic damage globally. Therefore, we employed an ensemble model combining Random Forests and CLIMEX to predict the potential global distribution of A. eugenii in historical and future climate scenarios. The results indicated that the maximum temperature of the warmest month is an important variable affecting global A. eugenii distribution. Under the historical climate scenario, the potential global distribution of A. eugenii is concentrated in the Midwestern and Southern United States, Central America, the La Plata Plain, parts of the Brazilian Plateau, the Mediterranean and Black Sea coasts, sub-Saharan Africa, Northern and Southern China, Southern India, Indochina Peninsula, and coastal area in Eastern Australia. Under future climate scenarios, suitable areas in the Northern Hemisphere, including North America, Europe, and China, are projected to expand toward higher latitudes. In China, the number of highly suitable areas is expected to increase significantly, mainly in the south and north. Contrastingly, suitable areas in Central America, northern South America, the Brazilian Plateau, India, and the Indochina Peninsula will become less suitable. The total land area suitable for A. eugenii under historical and future low- and high-emission climate scenarios accounted for 73.12, 66.82, and 75.97% of the global land area (except for Antarctica), respectively. The high-suitability areas identified by both models decreased by 19.05 and 35.02% under low- and high-emission scenarios, respectively. Building on these findings, we inferred the future expansion trends of A. eugenii globally. Furthermore, we provide early warning of A. eugenii invasion and a scientific basis for its spread and outbreak, facilitating the development of effective quarantine and control measures. Full article

A multiproxy methodology has been employed to characterise two granite anchors discovered on the seabed near the island of Nueva Tabarca (Alicante, Southeast Spain). According to the significant archaeological context where they were found, the studied anchors can be dated from the Roman ages (late Republican period). One of the most interesting aspects is the absence of regional geological outcrops with rocks compatible with the granite used in the production of the anchor, which shows a foreign origin consistent with the connection of the anchor to maritime transport across the Mediterranean Sea. The lack of precise information about the artifact’s origin underscores the interest and need for the application of petrological techniques to determine its provenance. The methodology utilised encompasses five distinct techniques: (1) non-destructive textural analysis using X-ray microcomputed tomography; (2) K–Ar dating; (3) petrological characterisation through optical microscopy; (4) geochemical characterisation using X-ray fluorescence and atomic absorption spectrometry. The results allow for a comparison of the anchor rock’s characteristics with various granite outcrops along the Mediterranean coasts (Eastern, Central, and Western sectors), suggesting potential source areas based on petrological compatibility with the material under study. The findings point to the origin of the Nueva Tabarca granite anchor being granite outcrops in Southern Italy (Calabria), reinforcing the connection between the Spanish southeastern coasts and Southern Italy. These results highlight the utility and significance of multiproxy petrological methodologies in the geoarchaeological study of decontextualised artifacts. Full article

The Atlanto-Mediterranean sea cucumber Holothuria tubulosa is a species of great ecological and commercial importance, making it a primary target for collection in the Mediterranean region. This study investigated the reproductive biology of H. tubulosa (Gmelin, 1793) in a coastal area of the Central Aegean Sea (Eastern Mediterranean) over a one-year period, from June 2021 to May 2022. Monthly sampling was conducted via dives at depths up to 10 m, alongside the recording of environmental and biometric data. Histological analysis revealed a synchronous annual reproductive cycle, with gonadal maturation beginning in April and peak sexual maturity observed in July and August, followed by a single spawning event from August to September. The sex ratio was 1:1.31 (male: female), and the size at first maturity was 255.3 mm. These findings provide essential insights into the reproductive physiology of H. tubulosa and further contribute to the development of sustainable stock management strategies for sea cucumbers in the Hellenic Seas. Full article

The Eastern Aegean Sea hosts a diverse assemblage of elasmobranchs, many of which are vulnerable or endangered. This study presents a fishery-independent assessment of species composition, catch characteristics, and spatial patterns in bottom trawl fisheries between Lesvos Island and Ayvalik. A total of 48 surveys were conducted between September 2022 and October 2024, identifying nine elasmobranch species, with Scyliorhinus canicula (small-spotted catshark) and Mustelus mustelus (common smooth-hound) dominating the catch. Biological parameters, sex ratios, and condition upon capture and release were recorded, while catch per unit effort (CPUE) and diversity indices were used to evaluate temporal patterns. The survival probability was negatively affected by the trawl duration and elevated temperatures, emphasizing the need for mitigation measures. Spatial models revealed high-density zones that likely function as foraging or nursery grounds. Seasonal shifts in community composition were also evident. Many non-commercial species were discarded irrespective of their size or condition. These findings underscore the ecological importance of this understudied region and support the need for spatially explicit, species-specific management strategies, including gear selectivity improvements, seasonal closures, and Electronic Monitoring. The study offers a critical baseline for enhancing the sustainability of elasmobranch populations in the Eastern Mediterranean. Full article

Holothurian fisheries have become a prominent métier in the Mediterranean due to increasing worldwide demand for sea cucumbers. In these newly explored grounds, their fisheries are poorly understood, especially considering the applied tactics and socioeconomics of the harvesting fleet. This study examines the small-scale holothurian (Holothuria) fishery métiers and associated socioeconomics in the Hellenic Seas—a main Mediterranean fishery ground. Holothuria fishing licenses increased in 2020 and stabilized (130) in the next years. Holothuria poli and H. tubulosa are the target species, caught by hand, using the surface air supply method or free diving. Most fishermen harvest holothurians close to the port of origin, and only the fleet from Kalymnos exploits remote grounds over the Greek territory. According to harvesting tactics, three economically viable métiers are practiced; however, shifting to alternative fishery resources is necessary to grant annual income. Sea cucumbers are sold fresh from fishermen to merchandisers who process the catch into final products (trepang) and export them. For most fishermen (64.7%), fishing for holothurians is the main occupation, gaining a highly variable monthly income (EUR 700 to 4000). The presented results refine the métiers and associated economics of an active holothurian fishery fleet, providing essential information for the viability of coastal fishery societies. Full article

Deep-sea trawling in the Mediterranean Sea, while economically significant, has profound ecological implications due to high discard rates and the practice’s impact on deep-sea biodiversity. This study examines the composition of discards and bycatch in Antalya Bay, a key deep-sea fishing area in the Eastern Mediterranean, during a commercial fishing season, focusing on seasonal and depth-related variations. Data were collected from deep-sea bottom trawl operations conducted between September 2016 and April 2017, analyzing species diversity and catch composition in terms of discarded and bycatch species. The results revealed an average discard rate of 70.7% of the total catch, with significant seasonal fluctuations. In total, 75 species were identified, comprising 48 Osteichthyes, 11 Elasmobranchii, 10 Crustacea, 4 Mollusca, 1 Brachiopoda, and 1 Echinodermata. Discarded species primarily consisted of juveniles of commercially valuable species (Merluccius merluccius and Lepidorhombus whiffiagonis), endangered elasmobranchs, and non-target benthic invertebrates. Depth-stratified analysis indicated that higher discard ratios and greater biodiversity loss occur at depths between 200 and 700 m, where slow-growing species and vulnerable deep-sea assemblages dominate. CPUE estimates for target, bycatch, and discarded species were calculated as 72.26, 145.12, and 385.52 kg/h, and CPUA values were calculated as 0.79, 1.59, and 2.92, respectively. These findings underscore the disproportionate impact of bottom trawling on deep-sea ecosystems and highlight the need for sustainable fisheries management strategies. Full article

Argonauta argo (Linnaeus, 1758), commonly known as the greater argonaut, is a pelagic octopod with a circumglobal distribution in warm and temperate seas. Although the species is occasionally reported in the Mediterranean Sea, confirmed in situ observations of live individuals remain scarce, particularly in the eastern basin. Here, we document the occurrence of a live female A. argo entangled in aquaculture nets at a sea bass (Dicentrarchus labrax) facility off the coast of Lesvos Island in the northeastern Aegean Sea, Greece. This represents the first confirmed observation in this part of the Mediterranean and only the second confirmed observation of a live individual in Greek waters. The individual was photographed in situ and identified based on diagnostic morphological features. The encounter occurred under specific hydrodynamic and environmental conditions potentially favorable to the species, including enhanced prey availability and structural refuge within the aquaculture infrastructure. This record contributes to the limited dataset on Mediterranean argonauts and underscores the need for further research into their ecology, distribution patterns, and potential interactions with anthropogenic marine structures. Full article

The relationship between global warming and heatwaves contributes to environmental risks. We investigate lake heatwaves (LHWs) in the Eastern Mediterranean, where dust intrusions are frequently observed. The dust intrusions are characterized by the arrival of warm air masses containing dust pollution from the desert. In saline lakes, LHWs caused by dust intrusions have not been investigated in previous studies. In our study we focus on this point. It was found for the first time that, in the hypersaline Dead Sea, a severe dust intrusion (aerosol optical depth of over 3) caused the formation of LHWs, as appeared in September 2015. At the water surface, the LHWs were represented by abnormally high daily maximal and minimal surface water temperature (SWT) in comparison with their seasonally varied 90th percentile thresholds for 10 consecutive days (7–17 September). The surface LHWs’ intensity was up to 3 °C. Satellite (MODIS-Terra and METEOSAT) SWT did not detect the LHWs. Surface LHWs were accompanied by subsurface LHWs down to a depth of 20 m. The subsurface LHWs lasted longer (16 days) than the surface LHWs (10 days). There was a 4-day delay between the first date of the surface LHWs (7 September) and the start date of the subsurface LHWs (11 September). The maximal intensity of the subsurface LHWs decreased with depth from 1 m (0.6 °C) down to 5 m (0.3 °C), followed by an increase (up to 0.6 °C) at the deeper layers (from 10 m to 20 m). Taking into account that, over the Eastern Mediterranean, desert dust has increased during the past several decades, one can expect frequent occurrence of dust-related intense persistent heatwaves in the Dead Sea in the coming years. This will contribute to additional water heating and further drying up of the Dead Sea. Full article

Understanding the trophic interactions and community structure of zooplankton is essential for assessing energy transfer in marine ecosystems. This study investigates the spatial and seasonal variations in stable carbon (δ¹³C) and nitrogen (δ¹⁵N) isotopes of dominant mesozooplankton groups across three sub-basins of the Eastern Mediterranean (North Aegean, Cretan, and South Ionian Seas) during two seasonal surveys (October 2014 and May 2015). Zooplankton samples were collected using a WP-2 net and analyzed for taxonomic composition, abundance, biomass, and stable isotopic signatures to assess trophic positioning. The results indicate that copepods dominated the zooplankton community at all stations, with Clausocalanus and Oithona juveniles being the most abundant taxa. Salps contributed significantly at certain stations, reflecting regional variations in the planktonic food web structure. Zooplankton δ¹⁵N values exhibited pronounced spatial and seasonal differences, with higher enrichment observed in 2014 compared to 2015. The calculated trophic positions highlight the variability in feeding strategies among copepod species, with Calanus helgolandicus occupying the highest trophic position (TP = 3.34) and Lucicutia spp. the lowest (TP = 1.22). Isotopic niche analysis identified two distinct feeding guilds: a group relying on phytoplankton and microzooplankton and another exhibiting broader trophic plasticity, including omnivorous and carnivorous taxa. These findings underscore the complexity of zooplankton trophic interactions in the Eastern Mediterranean and the role of regional hydrographic conditions in shaping the food web structure. This study provides essential baseline data for future research on the impacts of climate change and nutrient variability on Mediterranean marine ecosystems. Full article

The crucial role of plant–microbe interactions in seagrass growth and overall fitness is widely recognized and known to influence plant response to stress. Human-induced changes in coastal ecosystems necessitate efficient descriptors for seagrass monitoring. Recently, for Posidonia oceanica meadows, an integrative approach combining ecophysiological descriptors with bacterial communities has been successfully applied. Conversely, the mycobiota remains largely unexplored and fungal communities cannot be included yet as a putative descriptor. This study aims to evaluate the ecological status of two P. oceanica meadows in the Akrotiri Bay (Cyprus), located under different geomorphological features (depth and seabed type) and degrees of human pressure (port proximity vs. Marine Protected Area). A set of descriptors including morphometry, biochemical markers and bacterial communities collected in 2023 are compared with those collected, at the same sites, in 2017. Furthermore, the investigation of the leaf-associated microbial community included the underrepresented fungal communities, in addition to the bacterial ones, to evaluate their usefulness in evaluating the plant conservation status. Results indicated a good P. oceanica conservation status at both sites, showing an amelioration in the Limassol port meadow from 2017. In 2023, the biometrical/biochemical descriptors were found comparable across sites as the bacterial communities, differing from 2017 results. Noteworthy, fungal communities exhibited significant differences between sites, with a clear reduction, in the Limassol port meadow, of the dominant Posidoniomyces atricolor which is known as a specific colonizer of P. oceanica roots. These results confirm the strong relationship between P. atricolor and P. oceanica host, and suggest its sensitivity to environmental changes, able to keep track of ecological shifts. Full article

This study examines the relative sea-level changes during the Upper Holocene period along the south coastline of Cyprus through the investigation of beachrock formations and their impact on archaeological sites. Beachrock, as a natural indicator of past relative sea levels, provides valuable insights into the dynamic interplay between sea-level fluctuations and human settlements. The research integrates field observations, mineralogical and geochemical analysis, geochronological studies, and archaeological data to reconstruct past sea-level variations and their implications for coastal archaeological sites. The results reveal significant fluctuations in relative sea levels during the Upper Holocene, influencing the development and occupation of coastal archaeological sites. By elucidating the complex relationship between sea-level changes and human activity, this study contributes to our understanding of past coastal environments and their socio-cultural dynamics. Moreover, it underscores the importance of considering geological factors in archaeological interpretations and coastal management strategies in the face of contemporary sea-level rise. Full article

In the absence of in situ data, remote sensing becomes one of the most effective methods for analyzing the hydrodynamics of a basin. In the Gulf of Corinth, the lack of in situ information was addressed using 14 years of satellite data from the Copernicus database to investigate the water circulation dynamics of the Gulfs of Patras and Corinth. The combination of satellite observations and Data Interpolating Empirical Orthogonal Function (DINEOF) methods produced comprehensive maps detailing the hydrodynamic patterns in both gulfs. Despite the paucity of some parts of the datasets, the remaining data revealed key hydrodynamic features through their observations. From the western Patras Gulf to the eastern Corinth Gulf, gyres were the dominant features. The Patras Gulf is primarily characterized by a cyclonic gyre, while the Rio–Antirio Strait, which connects the two gulfs, exhibits unique dynamics due to internal wave activity and upwelling events. Currents generated near the strait flow toward the Corinth Gulf, where they are mostly trapped in an anticyclonic gyre near Itea Bay and a cyclonic gyre near Antikyra Bay. Our analysis highlights the unique dynamics of enclosed gulfs connected to the open sea via a strait. In this case, the Corinth Gulf acts as a smaller-scale analog to the Mediterranean Sea, offering insights into similar hydrodynamic behaviors. The updated hydrodynamic data also improve our understanding of sediment transport pathways and the chlorophyll distribution under present and past conditions. Full article

Under the threat of the climate crisis, renewables are an alternative that are aligned to European principles for clean energy and green transition strategies. Past studies have shown that the Eastern Mediterranean will present notable short- and long-term wind speed variability due to climate change. In this context, this study investigates the mean changes in wind energy potential (WEP) of a typical height of offshore turbines (80 m) over the climate sensitive area of the Aegean Sea during early, middle and late periods of the 21st century with reference to a base period (the historical period from 1970 to 2005). Data, available from EURO-CORDEX project under the moderate and extreme future scenarios (rcp4.5 and rcp8.5) as well as the recent past (historical) period (from 1970 to 2005), are analyzed here. In both future scenarios, the majority of model simulations indicates an increase in the WEP over the Aegean area as compared to the base period. In particular, the maximum increase in WEP is higher in the rcp8.5 scenario as compared to the rcp4.5 scenario. The most significant changes are shown over the southeastern (the straights between Crete and Rhodes Island) and the central-eastern Aegean area. Full article