Aeolian Islands Research Articles

Monitoring of contamination by microplastics on sandy beaches at Vulcano Island (Sicily, Italy) by hyperspectral imaging.

In this work, the monitoring and characterization of large microplastics (1-5mm) collected from sandy beaches of Vulcano Island (Aeolian Islands, Sicily, Italy) were carried out for the first time. Microplastics were sampled from two beaches, "Gelso" and "Sabbie Nere," in three different time periods. The following characteristics of microplastic samples were assessed: quantity, distribution, categories, color, polymer type, size, and shape parameters. The polymers were identified using hyperspectral imaging, whereas an automatic image analysis approach was employed to determine microplastics' morphological and morphometrical attributes. Finally, the microplastic diversity integrated index was computed to obtain information on the potential emission sources of microplastics. It was found that the concentration of microplastics varies from 0.27 particles/kg_dw to 1.35 particles/kg_dw with fragment being the main collected category, with minor amount of pellet, foam, film, and filament. The predominant color of microplastics was by far white, followed by blue and yellow. The identified polymers were polyethylene and polypropylene followed by expanded polystyrene, polyamide, polystyrene, and polyethylene terephthalate. The morphological and morphometrical characterization highlighted a large variability for most size and shape parameters. Finally, the Microplastics Diversity Integrated Index results showed average indices compared to the literature, with higher values for the "Gelso" site (0.656), indicating a higher heterogeneity of sources, with respect to "Sabbie Nere" beach (0.530).

Additional data on the ongoing naturalization of the non-native woody plant Duranta erecta ( Verbenaceae) in Sicily, Italy

We recorded the occurrence of Duranta erecta L. in the Aeolian Islands (Sicily, Italy), where it currently behaves as a casual alien. At the global scale, however, this woody species has shown highly invasive behaviour in different island ecosystems. On the basis of this evidence, we have investigated which ecological and biological traits may have allowed its establishment and spread, and could trigger its further expansion in the Aeolian Islands in the near future. Several factors seem to have favoured its success on a global scale, such as the wide edaphic and climatic range, the tolerance to anthropogenic disturbance, and the production of toxic metabolites that protect it from herbivore browsing and from competition with other plants. The study of the organisms that perform pollination and seed dispersal is probably the key to understanding the local naturalization of this plant, introduced about three centuries ago in Europe and the Mediterranean, here discussed in detail for the first time.

Enhancement of Biodegradation and Detoxification of Methylene Blue by Preformed Biofilm of Thermophilic Bacilli on Polypropylene Perforated Balls

Microbial degradation represents an eco-friendly alternative to traditional physicochemical treatments in removing persistent and toxic environmental pollutants, including synthetic dyes (i.e., methylene blue, MB) employed in different industries. The exploitation of thermophilic bacilli, such as those isolated from the shallow hydrothermal vents of the Eolian Islands (Italy), could provide valuable resources for the treatment of warm, dye-containing wastewater. In this study, we evaluated the ability of preformed biofilms on polypropylene perforated balls (BBs) of fifteen thermophilic bacilli, to decolor, degrade, and detoxify MB in aqueous solutions. Among them, BBs of Bacillus licheniformis B3-15 and Bacillus sp. s7s-1 were able to decolorize MB more than 50% in saline solution (NaCl 2%), incubated in static conditions at 45 °C for 48 h. At optimized initial conditions (10 mg L−1 MB, pH 5.2 for B3-15 or pH 4 for s7s-1), the two strains enhanced their decolorization potential, reaching 96% and 67%, respectively. As indicated by ATR-FTIR spectroscopy, the treatment with BB B3-15 was the most efficient in degrading the Cl–C and –NH groups of MB. This degraded solution was 40% less toxic than undegraded MB, and it has no impact on the bioluminescence of Vibrio harveyi, nor the growth of the marine diatom Phaeodactylum tricornutum. Biofilm formed by strain B3-15 on polypropylene perforated balls could be proposed as a component of bioreactors in the treatment of warm, dye-containing wastewater to concomitantly remediate MB pollution and simultaneously counteract harmful effects in aquatic environments.

Lithic production and the use of siliceous raw material in the Neolithic of Istria, Croatia

This article contains the results of the lithic analysis of assemblages from the Neolithic sites of Kargadur and Vižula in southern Istria, Croatia. The assemblages have been analysed in terms of reduction strategies and typology, with a special focus on raw material analysis and petrographic analysis. During the Early Neolithic, and especially the Middle Neolithic, raw materials circulated the Istrian peninsula, as evidenced by the presence of obsidian and other non-local (exogenous) chert at several sites. Obsidian is certainly an exotic material in this region, and items found at Kargadur come from the Aeolian islands. With these results we have tried to gain a better understanding of lithic production of the period, the approach of the Neolithic people to raw materials and the scope of the distribution network of high-quality chert.

Multi-approach study, digitization and dissemination of a Bronze-Age engraved cup found in Filo Braccio, Filicudi (Aeolian Islands, Italy)

This paper presents a multidisciplinary study combining photogrammetry, near-infrared (NIR) imaging and archaeological analysis to analyse a 1900-1800 BC engraved cup, found at the Bronze Age site of Filo Braccio in Filicudi, Aeolian Islands, Italy. The artefact is unique within the contemporary ‘Capo Graziano’ culture, featuring a rare complex figural scene engraved along the exterior walls; the “scene” provides insights into the prehistoric culture of Filicudi and the Aeolian Islands. The study focused on generating an accurate three-dimensional (3D) model to i) support archaeological research on the artefact's engravings and ii) create engaging digital media for remote and on-site visitors. Photogrammetry used high-resolution photographs taken around the object and control points for metric accuracy assessment. This study also utilises NIR and visible light imaging to examine the engraved cup. The photogrammetric workflow provided a realistic 3D model textured with both visible and NIR data: the 3D model enabled to improve the reading of the engraved scene, revealing horizontal registers of figures, while NIR imaging highlighted material inhomogeneity. The resulting 3D model achieved a high level of detail, with 4381407 faces and a root mean square (RMS) reprojection error of approximately 3.9 µm. The NIR imaging revealed additional surface details not visible in the standard photographs. For dissemination, the optimised 3D model was uploaded to Sketchfab with informative annotations, enabling remote study and cultural promotion of the artefact. This multi-approach methodology offers a valuable tool for comprehensive artefact documentation and analysis, providing new insights into the artefact's complex figural scene.

Geohazard features of the Aeolian Island slopes and the North-Eastern Sicily offshore

ABSTRACT The MaGIC project (Marine Geohazard along the Italian Coasts) had the aim of mapping the geohazard in the Italian seas and resulted in the production of numerous maps covering parts of the Italian Seas. In this paper, we present the maps: ‘The submerged portions of the Aeolian volcanic islands and the north-eastern Sicilian margin’, located in the south-eastern Tyrrhenian Sea. Both areas are affected by active geological processes, which represent important geohazards elements. Inthe submarine parts of the Stromboli volcanoremobilization of volcaniclastic deposits occur along the Sciara del Fuoco, where small-scale instabilities may represent a source of geohazard. Hydrothermal activity occurs on Enarete and Enaretino conical seamounts. The north-eastern Sicilian margin has a narrow continental shelf. Numerous canyon heads indent the shelf and, sometimes, reach close to the coast. Canyons have often a retrogradational trend and further eventual landward shift through sliding can iendangeri coastal or offshore infrastructures. Many of the canyons connect with leveed channels with widespread sediment instability. In the Gioia Basin, some of the channels connect to form the Stromboli slope Valley. Volcanic unrest or local and regional earthquakes are proven to have caused submarine landslides and tsunamis.

Ecology and Phenology of the Subtidal Brown Alga Sargassum furcatum (Ochrophyta, Fucales), a Likely Non-Indigenous Species from the Mediterranean Sea

This study provides new insights regarding the ecology and phenology of the likely non-indigenous canopy-forming species Sargassum furcatum on the central-eastern coast of Sicily (Italy, Central Mediterranean). This species was described for St. Thomas (Virgin Islands), and it was reported for the first time in the Mediterranean in 1995 in the Chafarinas islands (Spain, western Mediterranean). After the first report, this species was found in 2021 in several sites located along the eastern coast of Sicily (Italy), along the French Mediterranean coastline, in Corsica, and recently also in the Aeolian Islands (Italy). No phenological studies on this species have been ever carried out in the Mediterranean Sea. To conduct this study, a visual census activity was performed in three sites along the Ionian coast of Sicily throughout 2023, during which the length of the main axis of S. furcatum specimens was measured and the frequency of findings of the species during the year was noted. In this study, it was observed that S. furcatum shows a wide adaptability in terms of range of depth, temperature, light exposure, and type of substrate. Since the distribution of this species is mostly centralized in the western Atlantic Ocean, it is likely that S. furcatum entered the Mediterranean through the Gibraltar Strait. Consequently, the entrance of this species in this Basin could be further proof of the ongoing seawater warming and tropicalization of Mediterranean waters. From this point of view, it is important to keep monitoring the dynamics of S. furcatum in the Mediterranean Sea in order to understand its putative impacts on autochthonous communities.

Emergency management and risk reduction measures during the Vulcano (Aeolian Islands) unrest 2021–2023

Emergency management and risk reduction measures during the Vulcano (Aeolian Islands) unrest 2021–2023

Seeps and Tectonic Structure of the Hydrothermal System of the Panarea Volcanic Complex (Aeolian Islands, Tyrrhenian Sea)

High-definition bathymetry mapping, combined with the measurement of dissolved benthic fluxes and water column biogeochemical properties, allows for a description of new biogeochemical processes around the Panarea Volcanic island. Investigations focused on the CO2 releases from the bottom sea on the east of the Panarea volcanic complex provided insights into the geological setup of the marine area east and south of the Panarea Island. Between the Panarea Island and the Basiluzzo Islet lies a SW-NE-stretching graben structure where a central depression, the Smoking Land Valley, is bounded by extensional faults. Abundant acidic fluids rich in dissolved inorganic Carbon are released on the edges of the graben, along the extensional faults, either diffusely from the seafloor, from hydrothermal chimneys, or at the center of craters of different sizes. The precipitation of iron dissolved in the acidic fluids forms Fe-oxyhydroxides bottom sea crusts that act as a plug, thus preventing the release of the underlying gases until their mounting pressure generates a bursting release. This process is cyclic and results in intermittent gas release from the bottom, leaving extinct craters and quiescent chimneys. The measurement of dissolved benthic fluxes allowed us to estimate the volcanic DIC venting at 15 Mt of CO2 over the past 10,000 years. The fluxes are not distributed homogeneously but rather concentrate along fractures and fault planes, which facilitate their rise to the seafloor. The acidic fluids released affect the chemical properties and structure of the water column through the formation of layers with a lower pH under the pycnocline, which can limit volcanic CO2 release to the atmosphere. Further and continuous monitoring and investigation of the area are needed in order to complete a thorough picture of the variations in fluid releases through time and space. The importance of such monitoring lies in the development of a new method for detecting and quantifying the diffusive dissolved benthic fluxes on a volcanic sea bottom affected by hydrothermal seeps.

Contribution to the floristic knowledge of Lipari and Panarea Islands (Sicilia, Italy)

The inventory of the taxa collected in 2022 during the annual field trip of the Working Group for Floristics, Systematics and Evolution of the Italian Botanical Society is reported. The field trip was held from 19th to 22th April in the islands of Lipari and Panarea (Aeolian Islands, Sicilia). Overall, 1,664 herbarium specimens were deposited in public and private herbaria. The flora documented for the studied area amounts to 386 specific and subspecific taxa, belonging to 241 genera and 74 families. Centaurea aeolica, Helichrysum litoreum (Asteraceae), and Dianthus rupicola subsp. aeolicus (Caryophyllaceae) were the only three Italian endemics found in the study area, whereas 48 alien taxa were recorded. Dimorphotheca ecklonis (Asteraceae), Nassella tenuissima (Poaceae), Solanum torvum (Solanaceae), and Viola wittrockiana (Violaceae) are casual alien species new to Sicilia, whereas Oenothera odorata (Onagraceae) is a new naturalized alien species for the Italian vascular flora.

Deciphering the evolvement of microbial communities from hydrothermal vent sediments in a global change perspective

Microbial communities first respond to changes of external environmental conditions. Observing the microbial responses to environmental changes in terms of taxonomic and functional biodiversity is therefore of great interest, particularly in extreme environments, where the already extreme conditions can become even harsher. In this study, sediment samples from three different shallow hydrothermal vents in Levante Bay (Vulcano Island, Aeolian Islands, Italy) were used to set up microcosm experiments with the aim to explore the microbial dynamics under changing conditions of pH and redox potential over a 90-days period. The leading hypothesis was to establish under microcosm conditions whether the starting microbial communities of the sediments evolved differently depending on their origin. To profile the dynamics of microbial populations over time, biodiversity, enzymatic profile, total cell abundance estimations, total/respiring cell ratio were estimated by using different approaches. An evident change in the microbial community structure was observed, mainly in the microcosm containing the sediment from the most acidified site, which was characterized by a highly diversified microbial community (in prevalence composed of Thermotoga, Desulfobacterota, Planctomycetota, Synergistota and Deferribacterota). An increase in microbial resistant forms (e.g., spore-forming species) with anaerobic metabolism was detected in all experimental conditions. Differential physiological responses characterized the sedimentary microbial communities. Proteolytic activity appeared to be stimulated under microcosm conditions, whereas the alkaline phosphatase activity was significantly depressed at low pH values, like those that were measured at the station showing intermediate pH-conditions. The results confirmed a differential response of microbial communities depending on the starting environmental conditions.

The “Return” of Southern Italo-Romance Tonna: From Pseudocoordination to Adverb. A Case Study in Grammaticalization

The present work constitutes an initial look at the use of tonna, an invariable form of tornare ‘return’, used as a relatively uncommon V1 in southern Italo-Romance pseudocoordination structures. Along with losing its ability to inflect, grammaticalization of tornare, frequent across Italo-Romance, has consisted in its shift from lexical motion verb to a functional one with repetitive aspectual value, i.e. tonna mmanciu ‘I eat again’. This paper presents novel data from the variety of Eolian (Italo-Romance dialect of the Eolian Islands), which shows constructions previously unattested with invariable V1s, such as its embedding under functional verbs in non-finite clauses. A cartographic approach building on existing accounts of pseudocoordination V1s – centered on Cinque’s (1999, 2006) hierarchy of functional projections – leads us to consider two overarching explanations for tonna: that it is (a) a functional, aspectual head (in one of the two “repetitive” projections, viz. AspRepetitive(I), AspRepetitive(II)) or (b) an adverb, a specifier in these respective projections. Ultimately, the conclusion that it has (re)grammaticalized to the point of becoming a (deficient) adverb in the lower AspRepetitive(II) proves to be the most convincing from a theoretical perspective. A potential structural consequence is the syncretic status of the AspRepetitive(II) head.

A review of the tectonic, volcanological and hazard history of Vulcano (Aeolian Islands, Italy)

AbstractVulcano is one of the seven volcanic islands composing the Aeolian Islands archipelago (Southern Italy), which also includes three other active volcanoes. The island was originally a stratovolcano like Stromboli; afterwards, its shape turned towards a complex structure composed of several volcanic landforms of different sizes. This is due to the great variability of the tectonic and volcanic phenomena, presently showing a volcano made by two calderas, a lava dome complex and two small active cones. The largest of them is the tuff cone of La Fossa, hosted in the middle of a 3‐km‐wide caldera structure (La Fossa caldera), whose borders are visible on the southern and western sides of the island. Its last eruption occurred in 1888–1890. At present, Vulcano is characterized by weak shallow seismicity and intense fumarolic activity mainly concentrated within the crater of the La Fossa cone and along its rims during a recent unrest phase started in 2021, and measured with a multiparametric monitoring network.

Development of a Vessel Scheduling Optimization Model to improve Maritime Transport sustainability

The social and economic development of the islands is generally dependent on the interconnection level with the mainland obtained through maritime transport services. When connecting many islands, the route planning is essential and typically a variety of constraints must be considered. Various optimization methods have been established to improve cost-efficiency but today environmental concerns, like the reduction of CO2 emissions, have become mandatory. This paper proposes a vessel scheduling optimization model able to simultaneously consider compulsory and optional tasks and vehicle-dependent profits. The algorithm was applied to seven islands of the Tyrrhenian Sea located in front of Sicily, named “Aeolian Islands”. Considering the regional requirements in terms of minimum number of routes and maximum fare prices for each season, this research compared the optimal vessels option obtained maximizing the profit with the one obtained minimizing the emissions. In particular, we have conducted three different analyses, in the first one we have considered only the mandatory routes while the second one was carried out identifying a series of potentially attractive additional activities based on historical demand data provided by the company that currently manages the service. Finally, the third analysis addresses a scenario where older fuel-powered vessels were replaced with hybrid electric ones.

Mapping the microbial diversity associated with different geochemical regimes in the shallow-water hydrothermal vents of the Aeolian archipelago, Italy.

Shallow-water hydrothermal vents are unique marine environments ubiquitous along the coast of volcanically active regions of the planet. In contrast to their deep-sea counterparts, primary production at shallow-water vents relies on both photoautotrophy and chemoautotrophy. Such processes are supported by a range of geochemical regimes driven by different geological settings. The Aeolian archipelago, located in the southern Tyrrhenian sea, is characterized by intense hydrothermal activity and harbors some of the best sampled shallow-water vents of the Mediterranean Sea. Despite this, the correlation between microbial diversity, geochemical regimes and geological settings of the different volcanic islands of the archipelago is largely unknown. Here, we report the microbial diversity associated with six distinct shallow-water hydrothermal vents of the Aeolian Islands using a combination of 16S rRNA amplicon sequencing along with physicochemical and geochemical measurements. Samples were collected from biofilms, fluids and sediments from shallow vents on the islands of Lipari, Panarea, Salina, and Vulcano. Two new shallow vent locations are described here for the first time. Our results show the presence of diverse microbial communities consistent in their composition with the local geochemical regimes. The shallow water vents of the Aeolian Islands harbor highly diverse microbial community and should be included in future conservation efforts.

Financial Analysis of a Desalination–Wastewater Recycle Plant Powered by a DC-DC Photovoltaic-Batteries System on the Aeolian Islands, Italy

The scarcity of drinking water is an increasingly pressing issue in many regions of the world, even in areas up till now considered developed. Climate change deprives many populations of the amount of water necessary for human consumption and traditional crops. Therefore, finding new water sources and making their usage more efficient and able to adapt to new environmental conditions without worsening the situation with further pollution is becoming mandatory. In the case study considered here, set on the Italian island of Vulcano in the Central Mediterranean, we propose the economic analysis and financial sustainability of plants for the desalination and recycled wastewater, powered by a DC-DC photovoltaic tracker system with silicon crystal panels sustained by a daily pack of lithium batteries. We present an estimation of the necessary budget, and propose a mix of traditional and innovative financial instruments to construct and analyse the economic trends of the installations over 30 years, considering the specific area price levels, salaries and interest rates. Finally, through the net present value index, we evaluate the financial sustainability of the entire operation, namely, identifying the circumstances when funding and building these plants in areas as remote as the one considered here is cost-effective.

The Thermal Plumbing System of Stromboli Volcano, Aeolian Islands (Italy) Inferred From Electrical Conductivity and Induced Polarization Tomography

AbstractWe performed the first 3D island‐scale tomography of the electrical conductivity of Stromboli volcano (Aeolian Islands, Italy) using 2D acquisition lines (37.2 km) and a total of 18,880 measurements and 2,402 unique electrode locations. This 3D data set was inverted using a Gauss‐Newton algorithm, parallel‐processing on an unstructured tetrahedral mesh containing 678,420 finite‐element nodes and 3,580,145 elements to account for the topography of the volcanic island. The tomogram exhibits a conductive body (10−2–1.0 S m−1) consistent with the location of CO2 and temperature anomalies observed at the ground surface. It corresponds to the hydrothermal system with high electrical conductivity associated with alteration. In order to confirm this interpretation, a 2.5D large‐scale induced polarization tomography was performed crossing the volcano. The joint interpretation of the conductivity and normalized chargeability is done with a petrophysical model previously tested and verified at both shield‐ and strato‐volcanoes. This model implies that alteration (through the effect of the cation exchange capacity associated with clay minerals and zeolites) plays a strong role in both controlling the electrical conductivity and normalized chargeability at Stromboli volcano. A temperature tomogram, derived from the geoelectrical measurements, is consistent with surface temperature anomalies and the Very Long Period (VLP) seismicity related to the mild‐explosive activity. This survey displays at 600 m a.s.l. a lateral shift in the highest temperature location, also corresponding to the source of VLP seismicity. Structural boundaries have a major role in the hottest hydrothermal fluids rising below the active crater terrace of Stromboli volcano.

Advanced argillic alteration at Cave di Caolino, Lipari, Aeolian Islands (Italy): Implications for the mitigation of volcanic risks and the exploitation of geothermal resources

Four sites in the western sector of Lipari Island with still active hydrothermal activity are here considered. The petrography (mesoscopic observations and XRPD) and geochemistry (major, minor and trace elements chemistry) of ten representative and extremely altered volcanic rocks were characterized. Two types of parageneses of altered rocks are discriminable, one rich in silicate phases (opal/cristobalite, montmorillonite, kaolinite, alunite and hematite) and one in sulphates (gypsum, plus minor amounts of anhydrite or bassanite). The altered silicate-rich rocks are rich in SiO2, Al2O3, Fe2O3 and H2O, and depleted in CaO, MgO, K2O and Na2O, while the sulphate-rich ones are extremely enriched in CaO and SO4 in comparison with local unaltered volcanic rocks. The content of many incompatible elements is similar in altered silicate-rich rocks and lower in sulphate-rich ones with respect to the pristine volcanic rocks; conversely, almost all REEs are markedly enriched in silicate-rich rocks and heavy REEs are enriched in sulphate-rich altered rocks compared to unaltered volcanic rocks.Reaction path modelling of basaltic andesite dissolution in local steam condensate predicts the production of amorphous-silica, anhydrite, goethite, and kaolinite (or smectites and saponites) as stable secondary minerals and alunite, jarosite, and jurbanite as ephemeral minerals. Considering possible post-depositional reactions and admitting that the presence of two distinct parageneses is apparent, since gypsum is prone to form large crystals, it can be concluded that there is an excellent agreement between the alteration minerals occurring in nature and those predicted by geochemical modelling. Consequently, the modelled process is the main responsible for the production of the advanced argillic alteration assemblage of “Cave di Caolino” on Lipari Island. Since rock alteration is sustained by the H2SO4 solution produced by hydrothermal steam condensation, there is no need to invoke the involvement of SO2-HCl-HF-bearing magmatic fluids, in line with the absence of fluoride minerals.

Freight Distribution in Small Islands: Integration between Naval Services and Parcel Lockers

Freight transportation in urban areas represents an essential activity from the standpoint of economic development; in recent years, the spread of e-commerce (also accelerated by COVID-19) has contributed to increasing the demand for freight distribution over short distances. In most cities, the approaches and measures are often based on new technologies. Nevertheless, today there are contexts wherein delivery operations represent critical tasks to be solved. Furthermore, low accessibility areas, such as small islands, present further problems due to their exclusive dependence on maritime links (and often low-reliability services). This paper tackles this topic, formulating and solving a distribution problem by linking shipping services with last-mile distribution operated by means of an automatic delivery service (parcel lockers). A test application is proposed by considering the small island of Lipari in the archipelago of the Aeolian islands (Sicily, Southern Italy). The results show that such a type of service could reduce the user’s waiting time when compared to traditional home deliveries.

Quantitative morphology and mtDNA reveal that Lasius maltaeus is not endemic to the Maltese Islands (Hymenoptera, Formicidae)

Lasius maltaeus Seifert, 2020 was recently described as a Maltese endemic ant based on quantitative morphology, after decades of uncertainties over the identity of the local population, which has a phenotype resembling L. emarginatus (Olivier, 1791). At the same time, Sicilian L. emarginatus populations were discovered to diverge in their mitochondrial DNA to a degree that suggested heterospecificity. Considering the biogeographic similarity of Malta and Sicily, with land bridges connecting them repeatedly until the last glacial maximum, we questioned the assumption that L. maltaeus was endemic to Malta. We integrated quantitative morphology and mtDNA in the study of the Maltese and southern Italian populations phenotypically close to L. emarginatus. We discovered that the range of L. maltaeus extends over most of Sicily, while the true L. emarginatus replace it in the north-eastern sector of the island, the nearby Aeolian Islands, and the Italian peninsula. The distributions of L. emarginatus and L. maltaeus in Sicily follow biogeographic patterns recalling the island’s complex paleogeographic history. Further investigations should verify the existence of truly Maltese endemic ants, since the status of other allegedly endemic species is not strongly supported.