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Bottom trawling in submarine canyons can affect their sedimentary dynamics, but studies addressing this topic are still scarce. In the Gulf of Palermo (NW Sicily, SW Mediterranean Sea), bottom trawling occurs on the continental slope, but principally concentrates within Oreto Canyon. Hydrographic profiles and time series data of temperature, turbidity, and currents obtained by a CTD probe and by moored instruments, respectively, revealed increased turbidity values and the presence of bottom and intermediate nepheloid layers coinciding with periods of bottom trawling activity. The delay between the onset of trawling activities along the Oreto canyon axis and the increase in water turbidity at the mooring location indicate that trawling resuspended particles are progressively advected down-canyon by hydrodynamic processes. Topographic waves and near-inertial currents seem to contribute to the sediment transport of resuspended particles as bottom and intermediate nepheloid layers. Results presented in this paper highlight the complex relationship between hydrodynamic processes and sediment resuspension by trawling in submarine canyons. [ABSTRACT FROM AUTHOR]

Global warming is causing poleward expansion of species ranges. Temperate seas, in particular, are undergoing a process known as 'tropicalisation', i.e., the combination of sea-water warming and establishment of southern species. The Ligurian Sea is one of the coldest sectors of the Mediterranean and has thus been characterized by a dearth of warm-temperate species and a comparative abundance of cold-temperate species. This paper uses a time series of sea surface temperature (SST) and new records of thermophilic fish species to reconsider the biogeography of the Ligurian Sea. SST has risen by about 0.7 °C on average between 1948 and 2023, but two phases may be distinguished: a cool one (ended in the mid-1980s) and a warm one (still ongoing); the latter phase shows alternating periods of rapid warming and comparatively stationary temperature. The arrival of thermophilic species coincided with the periods of rapid warming; some of these species were established in the subsequent stationary periods. Heatwaves and climate-related diseases associated with the periods of rapid warming have caused mass mortalities of autochthonous species. Our knowledge on the biogeography of the Ligurian Sea was established during the cool phase; the present situation, however, calls for re-defining the chorological spectrum of the Ligurian Sea biota. [ABSTRACT FROM AUTHOR]

In the Mediterranean Sea, the bivalve genus Pinna is represented by two species: the endemic Pinna nobilis and the (sub)tropical Atlantic Pinna rudis. P. rudis is generally less common and mostly restricted to the warmer regions of the western Mediterranean. However, since a mass mortality event, caused by a pathogen infection, has brought P. nobilis to the brink of extinction, records of P. rudis have increased in several Mediterranean regions, where it had not been previously observed. This paper reports on the presence of several P. rudis individuals in the Ligurian Sea, the northernmost reach of this species in the western Mediterranean. P. rudis has become increasingly common between 2021 and 2023, with a total of 28 new records from seven localities along the Ligurian coast. The size of the individuals and their estimated growth rate (3.6 cm·a−1) indicated that a recruitment event most likely took place in summer 2020, when P. nobilis was no longer present in the area. Our observations suggest that the recruitment success of P. rudis increased following the decline of P. nobilis. However, considering the thermophilic nature of P. rudis, in all likelihood, the ongoing water warming is playing a crucial role in the successful establishment of this species in the Ligurian Sea. A full understanding of the recent range expansion of P. rudis in the Mediterranean is far from being achieved, and whether P. rudis will be able to fulfil the ecological role of P. nobilis is difficult to predict. Large scale monitoring remains the only effective way to know about the future of Pinnids in the Mediterranean Sea. [ABSTRACT FROM AUTHOR]

In the Mediterranean, incidental captures in fishing gear contribute to the high mortality of loggerhead turtles (Caretta caretta). Understanding the effects of bycatch is complex and requires robust knowledge of baseline population parameters such as abundance and density, as well as an understanding of animals' distribution in relation to commercial fishing efforts. Based on data collected during multi-species line transect aerial surveys conducted between 2009 and 2017, we present density and abundance estimates, corrected for availability bias, for a large sector of the central Mediterranean, discuss temporal and spatial patterns and provide Potential Biological Removal (PBR) values for the monitored areas. Sightings data were also used to evaluate the spatial and temporal usage areas. Strong latitudinal and longitudinal gradients in density, abundance and area usage emerged from the analysis, with turtles occurring in higher numbers in the deeper pelagic waters of the Tunisian Plateau, the Ionian Sea and the Gulf of Taranto, irrespective of the season. PBR values derived from this study are likely unsustainable. This paper investigates the implications of commercial fisheries for Mediterranean loggerhead turtles across an area rarely included in sea turtle monitoring and has the potential to be relevant towards informed management and conservation of this species and highlights the necessity of international collaborative efforts in the region. [ABSTRACT FROM AUTHOR]

This paper investigates the dynamics of the cross-shore extensions of banquettes, a sedimentary structure mostly made by rests of Posidonia oceanica (L.) Delile, in a sandy urban beach located in the Gulf of Cagliari, Italy, western Mediterranean. A video monitoring station was installed above the promontory south of the beach. We analysed a four-year image database and related these dynamics to wave and wind parameters (obtained from the Copernicus and ERA5 databases) from September 2016 to September 2020. Our results showed that banquette deposition occurred in concomitance with the presence of leaf litter in the surf zone associated with mild storm events. Erosion of the banquettes occurred during more intense storms. When leaf litter was not present in the surf zone, banquettes were not deposited even with mild storms. Wind can influence the banquette dynamics: under certain conditions of speed intensity, the banquettes may be removed offshore, supplying litter in the surf zone, or they may be covered by sediment. The permanence of the banquettes on the beaches also depended on their composition: when the banquettes were intertwined with reeds, their removal by the waves did not occur even during intense storms, and this sedimentary structure can protect the beach from flooding. [ABSTRACT FROM AUTHOR]

Featured Application: The featured application of this paper focuses on the impact of climate change on ecosystem services provided by the Phyllognathus excavatus beetle, specifically its role in recycling organic matter. The study highlights that dung beetles, including Phyllognathus excavatus, play a crucial ecological role in nutrient cycling, waste decomposition, and soil improvement. These beetles facilitate the breakdown of organic matter, such as dung, and contribute to the recycling of nutrients back into the ecosystem. However, climate change can disrupt the life cycles and habitat suitability of these beetles, affecting their ability to perform their recycling function effectively. Changes in temperature and precipitation patterns can alter the availability of fresh dung, which is essential for successful reproduction and larval development. Shifts in rainfall patterns and increased temperatures can also impact the timing of dung decomposition and alter the composition of microbial communities associated with dung, indirectly affecting the survival and fitness of dung beetles. Determining the resilience of ecosystem services, such as recycling, and creating effective conservation strategies to mitigate the negative effects of climate change on these significant ecological processes depend on our ability to understand the potential effects of climate change on Phyllognathus excavatus and other dung beetles. Climate change poses a significant threat to ecosystems, food security, and human well-being. This study focuses on the Phyllognathus excavatus beetle, an important insect species in the Mediterranean region with ecological importance in nature recycling of organic wastes. The aim of this study is to assess its current habitat suitability and predict its distribution under future climate scenarios. The beetle's occurrence records were gathered and climate information, including 19 bioclimatic variables, was retrieved from the Global Biodiversity Informatic Facility (GBIF) and WorldClim depository, respectively. The MaxEnt algorithm was used to calculate habitat appropriateness using geographic information systems (GISs) and species distribution modeling (SDM) with an accuracy of 0.907 using the AUC test. The findings show that the annual mean temperature is the most important factor, with the beetle flourishing in temperatures between 13.9 and 19.1 °C. The distribution is greatly impacted by the mean temperature of the warmest quarter. Future projections using different climate scenarios suggest potential changes in the beetle's distribution. By integrating climate data and occurrence records, this study provides insights into the vulnerability of Phyllognathus excavatus to climate change and identifies regions where its habitat may be at risk as 81% of its current habitat will be lost. The research helps to prioritize efforts to reduce the harmful effects of climate change on insect biodiversity and to design effective conservation strategies. Overall, this study advances our knowledge of the Phyllognathus excavatus beetle's present and projected distribution patterns in the Mediterranean region under the influence of climate change. It illustrates the significance of taking into account how climate change would affect insect populations and the use of SDM and GIS tools for researching and protecting insect biodiversity. [ABSTRACT FROM AUTHOR]

Coastal marine monitoring is a specialized field of research requiring the acquisition of long-term datasets regarding the main physico-chemical and biological variables that characterize the aquatic environments as a key strategy to depict the environmental status and its possible changes due to natural or anthropogenic stressors. During the last few decades, the devices used in this research field underwenta great evolution. This progress has been made possible by the advancement of the technologies and data processing that have resulted in the availability of new systems for autonomous monitoring. This paper reviews the state of the art of coastal marine monitoring systems developed since 1988 at the Istituto Sperimentale Talassografico—Experimental Thalassographic Institute of Messina (CNR IST), a part of the Italian National Research Council, and continued when the Institute was incorporated into the Istituto per l'Ambiente Marino Costiero—Institute for Marine Coastal Environment (IAMC). The research activity focused on coastal marine monitoring starting at the end of 1988 and lasting for about 30 years, up to the re-organization of the CNR Institutes. This event led to the redistribution of former marine research centers into new Institutes, with missions different to those characterizing the previous structures. Monitoring experiments were performed, and new automatic devices were developed and tested. Some of these systems, including water samplers and integrated data acquisition and transmission systems, are reported. [ABSTRACT FROM AUTHOR]

Simple Summary: Consumption and excessive use of substances or items that are taken for granted in our daily lives such as personal care products, plastic objects, and medicines inevitably lead to their release into marine and freshwater systems with, unfortunately, potentially devastating consequences over time. For this reason, it is of crucial importance that the scientific community, as well as society, is aware of the environmental problems linked mainly to the release of contaminants into the sea. In this context, the Mediterranean Sea is a special biodiversity hotspot of marine fauna and flora. Nevertheless, it is becoming a source of concern due to the presence of emerging pollutants. In the present paper, the specific focus on the catshark Scyliorhinus canicula, as a vertebrate species, and on the Mediterranean mussel Mytilus galloprovincialis, as an invertebrate, lies in their ability to provide appropriate information about the health conditions of their surrounding environment. The studies reported on this topic show that it is rather evident that entire aquatic ecosystems suffer from anthropogenic pollution. Therefore, this review aims to collect and demonstrate its effects on the environment and organisms' health. In this historical context, the Mediterranean Sea faces an increasing threat from emerging pollutants such as pharmaceuticals, personal care products, heavy metals, pesticides and microplastics, which pose a serious risk to the environment and human health. In this regard, aquatic invertebrates and fish are particularly vulnerable to the toxic effects of these pollutants, and several species have been identified as bio-indicators for their detection. Among these, bivalve molluscs and elasmobranchs are now widely used as bio-indicators to accurately assess the effects of contaminants. The study focuses on the catshark Scyliorhinus canicular and on the Mediterranean mussel Mytilus galloprovincialis. The first one is a useful indicator of localised contamination levels due to its exposure to pollutants that accumulate on the seabed. Moreover, it has a high trophic position and plays an important role in the Mediterranean Sea ecosystem. The bivalve mollusc Mytilus galloprovincialis, on the other hand, being a filter-feeding organism, can acquire and bioaccumulate foreign particles present in its environment. Additionally, because it is also a species of commercial interest, it has a direct impact on human health. In conclusion, the increasing presence of emerging pollutants in the Mediterranean Sea is a serious issue that requires immediate attention. Bivalve molluscs and elasmobranchs are two examples of bio-indicators that must be used to precisely determine the effects of these pollutants on the marine ecosystem and human health. [ABSTRACT FROM AUTHOR]

In this paper, the effectiveness of transplanted (either created or restored) seagrass meadows as a coastal protection measure is assessed through a five-step methodology. The analysis is focused on a stretch of the Catalan coast (NW Mediterranean) which is a fetch-limited environment. The results show that even considering conservative values for the meadow parameters (plant diameter, meadow density and canopy height), significant reductions of the annual average wave heights reaching the beach may be obtained, reducing flooding and erosion risks. Therefore, the investment in the conservation and restauration of seagrass meadows for protecting coastal areas from erosion and flooding is a measure that must be considered, due to the multiple benefits that they provide including ecosystem services. In addition, the proposed methodology may be a useful tool for coastal managers to help them in the design of seagrass meadows for coastal protection. [ABSTRACT FROM AUTHOR]

In the last decades, the popularity of video games has been increasing thanks to their unique ability to engage their audience and create empathy. Among them, serious games have additional purposes besides entertainment, such as learning and behaviour change. Serious games, in fact, have been successfully applied to different fields, including education, health, tourism, and cultural heritage. In this context, the paper describes a novel serious game developed for increasing awareness and promoting the Underwater Cultural Heritage (UCH). In particular, the paper focuses on the Dive in the Past Serious Game which allows users to simulate a virtual dive into the Mediterranean Sea to explore accurate and life-sized 3D reconstructions of underwater archaeological sites. The purpose of the game is twofold: to engage diver and non-diver tourists into a virtual interactive exploration of underwater sites through digital storytelling and challenges; to increase awareness and knowledge on Mediterranean UCH. This work has been carried out in the context of the MeDryDive project, an EU co-funded under the COSME Programme, which aims to create personalized dry dive experiences for the promotion of Mediterranean UCH sites as distinctive tourism destinations. [ABSTRACT FROM AUTHOR]

Climate change is altering the functioning of ecosystems and species distribution worldwide, with negative impacts on human activities, including fisheries. The Adriatic Sea is an extremely productive area for fisheries, due to the strong outflow of nutrients from rivers and the periodic mixing of nutrients from the Mediterranean. However, the Adriatic Sea is also a semi-closed basin, where species do not have the ability to move to higher latitudes to avoid warming of the waters. Climate change acts on biodiversity in a variety of ways, such as causing changes in the trophic network—favoring the intake of thermophilic alien species, often in competition with local species—and altering the biological cycles of acclimatized marine species to temperate–cold climates. These problems become critical factors for the survival of species and for fisheries relying on these resources. Within this context, to have estimates of possible modifications of the nektonic community in the near future could be quite useful for preparing adaptation plans. In this paper, using Maximum Entropy models under RCP 4.5 and 8.5 scenarios, we estimated the future habitat suitability for a set of marine nektonic species of different thermal affinity (e.g., cold, temperate and warm species) within GSA17 (Northern and Central Adriatic Sea), among the most productive—and most exploited—areas of the Mediterranean Sea. This study shows how, at the current pace, climate change could modify marine ecosystems to the extent that future habitat suitability will decrease for nearly half of the species considered, with a decrease in landings from 13.5 to 86.9%, depending on the scenario. Only for the blue crab Callinectes sapidus has an increase in habitat suitability been observed. For most of the species considered, temperature was the most important variable to explain the probability of relative presence within the GSA17. On the other hand, GSA17 climatic conditions in the near future under the tested scenarios could become a suitable environment for tropical species, which could find here a suitable habitat, at least in terms of thermal features. Results of the present study can help the management of fishery resources and local markets in the near future, providing information to predict changes in the composition of the aquatic community and draw up management plans that take into account the effects of climate change. [ABSTRACT FROM AUTHOR]

In recent years, numerous projects for floating PV systems have been developed. These plants of various sizes have mainly been installed on enclosed lakes or basins characterised by the absence of external forcing related to waves and currents. However, offshore installation would allow the development of such plants in areas where land is not available, such as islands. This paper analyses the state of the art of floating PV, describes the design of a floating PV platform and the development of a numerical model to evaluate the system performance in an offshore environment. The case study of the island of Lampedusa is then analyzed: starting from a single floating foundation with its mooring system, a floating PV system is designed to meet the island's electricity needs. In order to provide the competitiveness of the system, a techno-economic analysis is carried out, evaluating the main cost items of Capex, Opex and LCOE. Although the LCOE obtained is significantly higher than a traditional solar plant installed on land, this technology is competitive compared to other offshore marine technologies such as offshore wind and wave energy. [ABSTRACT FROM AUTHOR]

The studies on the bioinvasion phenomenon focus mainly on the biological and ecological traits of a species, while scattered literature is addressed to a correct systematic assessment and an updated geographical distribution on the whole. It is noteworthy that non-indigenous species should be monitored on both sides of their range, i.e., towards the front of dispersal and beyond the original range. The backside range boundaries are not often monitored or well delimited; thus, the novel global distribution of an invasive taxon is not often accurately delimitated. A model species for highlighting criticisms about the scarce knowledge on the novel range was chosen. Brachidontes pharaonis is a mussel that has successfully colonised the Mediterranean Sea, following an immigration pathway through the Suez Canal from the Red Sea, presumably from a wider Indo-Pacific area. In this case, the Indo-Pacific boundaries have been overlooked and are still misunderstood due to diverse causes, principally as the synonymy with the congeneric B. variabilis has created confusion in the taxonomic identification. The present review demonstrates that the borders of the B. pharaonis range are still unclear and that the species should be analysed in a wider geographical area. Records of B. pharaonis from Southeast Asia should be treated with caution as this area is out of its range. The Indian and Pacific Oceans host the taxon B. variabilis, composed of two potential cryptic species. Data from the literature highlight the importance of the integrative taxonomic approach to solving various issues concerning the species group complex, morphological variations and cosmopolitan claims of species. [ABSTRACT FROM AUTHOR]

The Mediterranean Sea is known to be a hot spot for marine biodiversity, especially if considering the highly specialized Heterobranchia mollusks. In recent years, there has been increasing effort to fill some knowledge gaps existing on Mediterranean heterobranch diversity, but, to date, several potentially interesting habitats remain unexplored. In fact, most studies have been focused on sea slugs inhabiting coastal areas and lakes, but those living in extremely variable areas like Mediterranean rocky tide pools remain almost completely ignored even if it is reported worldwide that they can host a high sea slug diversity. In this context, the rocky tide pool system near the 'Passetto' urban beach (Ancona, Italy) in the North Adriatic Sea (Mediterranean Sea) represents a biodiversity hot spot, highlighting the importance of the conservation of this peculiar habitat. A preliminary quantitative survey on the associated Heterobranchia unveiled a thriving community residing in this limited and fragile habitat, and it inspired a more detailed investigation as performed in the present study. In order to reveal the presence of species that have gone unnoticed, an in-depth study was carried out between 2018 and 2022, which aimed to amplify the knowledge on this vulnerable environment and the fauna associated with this as yet poorly known habitat. Tide pooling activities corroborated by photographic analyses allowed the recording of 45 taxa in total and the addition of 25 species to the previously known list. Within those, (i) two species were potentially new to science, (ii) one was recorded in the Mediterranean Sea for the first time, (iii) two species were added to the Italian fauna, and (iv) one species constituted a new record for Sector 9 of the Italian Seas. [ABSTRACT FROM AUTHOR]

Benthic diatoms have been studied in different areas of the Mediterranean Sea, but no data have been available for Israeli coastal waters until the present time. In this work, the composition, ecology, and phytogeography of diatoms of the macrophytes epiphyton are presented for the first time. Altogether, 85 diatom taxa were found among the epiphyton of 25 species of green, brown, and red macroalgae from the Israeli coast between March and May of 2021. These diatoms represent three classes, 17 orders, 26 families, and 41 genera. The taxonomic composition, ecology, and phytogeography of species are discussed. The distribution of diatoms are compared to that of other macrophytes and anthropogenic loads across the shoreline. The dominant species are given. Ecological characteristics and abundance in communities of revealed species are represented and statistically analyzed. The index of saprobity S varies between 1.69–2.71. Sites that stressed aquatic communities are indicated. The influence of the anthropogenic loads on the coastal territories is defined as a major factor that stimulated diatom species richness. Sites with anthropogenic stress for aquatic communities are indicated. Based on the composition of bioindicators, it is concluded that the section of the Israeli coast studied is oligo-mesotrophic compared to the eutrophic Gulf of Tartus. [ABSTRACT FROM AUTHOR]

The morphodynamics of the Leucate double-crescent bar system was studied over twenty years using bathymetric data supplemented by satellite images and video monitoring. Eleven different bar typologies were identified, mostly based on existing beach state classifications (Low-Tide Terrace, Transverse Bar and Rip, Rhythmic Bar and Beach), also including new heterogeneous typologies (TBR/LTT, RBB HP/RBB, TBR/RBB). The inner bar shows greater variability, with 10 different typologies observed, while the outer bar shows only three different typologies. Summer low-energy periods are dominated by TBR/LTT and TBR typologies, while RBB, although common throughout the year, dominates winter periods along with disrupted bar configurations. The return to less energetic periods in spring is associated with the establishment of heterogeneous typologies. The outer bar has a fairly stable position, although breaches at the embayments and slight movements of its horns can occur following particularly energetic episodes. The inner bar, on the other hand, is much more dynamic, with more common breaches at the embayments and significant cross-shore movement of the horns. Seasonal changes in bar typology do not lead to bar renewal through destruction/reconstruction. Overall, the morphological and typological characteristics of the bar system described here seem somewhat unique compared to the existing literature. [ABSTRACT FROM AUTHOR]

The large variation in vertebral shape and calcification observed among elasmobranch species prevents using a single method for enhancing growth bands and reading age. Further, estimating age and growth parameters can be difficult or impractical when samples are incomplete due to the bycatch of a size-selective fishery. Using a single and rapid method, age readings were obtained on the vertebrae of four batoid species, namely 53 individuals of Dasyatis pastinaca, 51 of Raja asterias, 15 of Torpedo marmorata, and 55 specimens of Torpedo torpedo, from the local small-scale trammel net fishery in the coastal waters (5–20 m depth) of the Central Tyrrhenian Sea during 2019–2021. Based on these data, a statistical routine was developed to obtain multiple estimates of age and growth parameters for incomplete samples due to size-selective fishing. The acceptable agreement between and within readers (intra and inter-reader disagreement < 5%) and the rate of increase in vertebral size with body size (differently ranked across species) demonstrated the consistency of the enhancing method. The parameters estimated by the Von Bertalanffy and Gompertz growth models matched the data available in the Mediterranean Sea for the species studied, with D. pastinaca, T. torpedo, and R. asterias showing the lowest (k = 0.05–0.12), intermediate (k = 0.112–0.19), and highest (k = 0.18–0.23) growth rates, respectively, in line with the life history traits of these species. Overall, the method proved effective both in delineating band pairs in vertebrae of different species and in reliably estimating the age and growth parameters of problematic samples due to size-selective fishing. The proposed method supports the collection of comparable demographic data from other areas where similar multi-specific assemblages are bycatch of size-selective fisheries impacting potential nursery areas and other essential habitats for elasmobranchs. [ABSTRACT FROM AUTHOR]

This bibliographic study addresses key aspects related to fishing, product safety, and climate change in the Adriatic Sea region. The examination of product safety focuses on the assessment of contaminants originating from human activities such as industry, mining, agriculture, and household waste disposal. The contamination of the aquatic environment has emerged as a pressing global concern, extending to the Adriatic basin. Aquatic organisms, including fish, are prone to accumulating pollutants directly from polluted water sources and indirectly through the food web. The bio-accumulation of potentially hazardous substances, particularly heavy metals, pesticides, PCBs, PAHs, and antibiotic resistance in aquatic organisms, poses a significant threat to human health. Climate change effects will deplete our seafood supply in terms of quantity and safety owing to negative consequences such as higher levels of pollution, parasites, viruses, infections, acidification, and toxicities such as shellfish poisoning. Global food safety strategies should be developed to reduce greenhouse gas emissions and promote environmentally friendly technology, which indirectly affects seafood quality and microbiological safety, especially for the Adriatic Sea, which is part of the Mediterranean Sea, characterized by the most polluted waters in the world. [ABSTRACT FROM AUTHOR]

The southern Alboran Sea is a dynamic ecosystem and is highly influenced by Atlantic waters. Unfortunately, despite the importance of the mesozooplankton in this ecosystem, the number of studies on this ecosystem is low. The composition and abundance of mesozooplankton communities were studied during the summer season (July 2017) along the Moroccan Mediterranean coast between M'diq and Saïdia. A total of 14 mesozooplankton groups were identified and were dominated by copepods (48%) and cladocerans (35%). Abundance and biomass spatial distribution distinguished two main regions east and west of Al Hoceima. The same distribution pattern was observed when using copepod and cladoceran abundance. Environmental parameters (temperature, salinity, and nutrients) differed in these two regions. Our results confirm the hypothesis that the water flux from the Atlantic Ocean is responsible for the eastward gradients of the mesozooplankton abundance and diversity. Copepods were the most diversified group with 27 species, dominated by Paracalanus parvus (30.5%), Temora stylifera (14%), and Oncaea venusta (12.4%). The diversity index (H') of copepods varied between 1.35 and 2.8 bits ind−1, and the regularity index (J) varied between 0.21 and 0.45, without a remarkable longitudinal gradient. Multivariate analysis showed that the mesozooplankton biomass, abundance, and distribution were influenced mainly by hydrology (gyres), by temperature and salinity, and to a lesser degree by phytoplankton. [ABSTRACT FROM AUTHOR]

In recent years, investments in renewable energy sources have been increasing in order to reduce fossil fuel consumption and mitigate the effects of global warming on the marine ecosystem. Recent studies have shown that marine current energy, which is one of the renewable energy sources, can provide very high energy gains. This study focuses on the Mediterranean region, which is one of the areas where the impacts of climate change are most clearly felt. The annual and seasonal analysis of the current velocity in the study area between 2016 and 2018 was carried out using remote sensing technology, and potential energy production was calculated using an underwater turbine system we selected. As a result of the study, it was determined that the maximum current velocities were 2.2 m/s in 2016 and 2017 and 2.7 m/s in 2018. In addition, it was observed that the current speed was approximately 2.7 m/s in the spring months and 2.0 m/s in the summer months. In the fall and winter months, it was 2.1 m/s and 2.2 m/s, respectively. Research has shown that the study area, especially in the eastern coastal areas, has the capacity to generate approximately 10 GWh of energy per year with the use of underwater turbine systems. [ABSTRACT FROM AUTHOR]

Enhancing resilience against flooding events is of great importance. Eastern Iberian Peninsula coastal areas are well known for high intensity rainfalls known as DANA or "cold drop". Extreme records in 24 h can exceed the annual average of the historical series. This phenomenon occurs normally in autumn due to convective storms generated by the existence of cold air in the upper layers of the atmosphere combined with warm winds coming from the Mediterranean Sea. In many coastal areas of the Eastern Iberian Peninsula, their flat topography, sometimes of a marsh nature, and the natural (e.g., dune ridges) and man-made (e.g., infrastructures) factors, result in devastating flooding events of great potential damage and risk for urban and rural areas. In this context, this paper presents the case study of the town of Oliva (Valencia, Spain) and how in a flooding event the flow tends to spread and accumulate along the flat coastal strip of this populated area, causing great potential damage. From that point, the paper discusses the particular issues that flood studies should consider in such flat and heavy rainy areas in terms of the hydrological and hydraulic models to be conducted to serve as the key tool of a correct risk assessment. This includes the correct statistical simulation of rainfalls, the hydrological model dependency on the return period and the correct geometry definition of all possible water barriers. An analysis of the disturbance that climatic change effects may introduce in future flooding events is also performed. [ABSTRACT FROM AUTHOR]

This paper presents an assessment of offshore wave energy potential at the scale of the whole Mediterranean Sea. The offshore wave data were propagated, by means of numerical modeling, toward four Italian coastal areas, namely stretches of coast of Tuscany, Liguria, Sardinia and Sicily. For each area, the wave power and the monthly, seasonal and annual variability at water depths of 50 m and 15 m were analyzed and hotspots were located. The results show strong variability of the wave energy potential from point to point of the same area thus highlighting the need for spatially detailed analysis. The higher values of wave energy potential are located in the hotspots of Sardinia and Sicily, at 11.4 kW/m and 9.1 kW/m, respectively. The Tuscany and the Liguria hotspots are characterized, respectively, by 4.7 kW/m and 2.0 kW/m. In order to point out which state of the art WEC is best suited for the Italian areas, the performances of six different state of the art Wave Energy Converters (WECs) were evaluated. Finally, a comparison of the performances of each WEC in the selected Italian sites and in some European (EU) oceanic sites was conducted. The energy potential in the most energetic EU oceanic site, among those here investigated, is up to 38-times greater than the potentials in the studied Italian areas but the power output, of the best WEC technology, is no more than nine times greater. [ABSTRACT FROM AUTHOR]

The main purpose of this paper is to analyze the energy production in the Maltese islands, focusing on the employment of renewable energies in order to increase their energy independence. The main renewable source here proposed is wave energy: thanks to a strategic position, Malta will be able to produce electrical energy using an innovative type of Wave Energy Converter (WEC) based on the prototype of a linear generator realized by University of Palermo. The use of this new technology will be able to cut down the electrical energy production from traditional power plants and, consequently, the greenhouse gas emissions (GHG).Wave energy source and off-shore photovoltaic (PV) technology are here proposed. Particularly, the installation of 12 wave farms, for a total installed capacity of 86 MW, will generate about 9.5% of Malta's energy requirement in 2025, while the installation of 9.6 MW of off-shore PV will generate about 0.73%. [ABSTRACT FROM AUTHOR]

The paper is focused on the analysis of the electrical energy sector in the Maltese islands, focusing on the employment of Renewable Energies in order to increase its energy independence. The main renewable source here proposed is wave energy: thanks to its strategic position, Malta will be able to generate electrical energy through the use of an innovative type of Wave Energy Converter (WEC) based on the prototype of linear generator designed and developed by the University of Palermo. This new technology will be able to cut down the electrical energy production from traditional power plants and, consequently, the greenhouse gas emissions (GHG). Wave energy source and off-shore photovoltaic (PV) technology are proposed here. Particularly, the installation of 18 wave farms, for a total installed capacity of 130 MW, will generate about 5.7% of Malta's energy requests in 2025, while the installation of 60 MW of off-shore PV will generate about 4.4%. [ABSTRACT FROM AUTHOR]

A new set of observations has been compiled for tsunamis occurring in Greece and in the surrounding areas from 1900 to 2023. A variety of information sources has been collected and examined, including scientific and press reports, books, eyewitness accounts, pictorial and video material, and tide-gauge records. New material was also collected during our field surveys in the islands of Cephalonia, Karpathos, and Kos. Our investigation included 26 distinct events and revealed several tsunamis. The majority of them have remained unknown so far in the tsunami community. Our compilation also included little-known events for which further documentation has been provided. Among others, of particular importance is the collection of new information about the well-known tsunami associated with the 9 February 1948 large earthquake in Karpathos Island as well as the unknown so far series of local but powerful tsunamis generated during the seismic crisis of very strong earthquakes that destroyed the Ionian islands during August 1953. The new observational material collected is significant for the enrichment of existing tsunami catalogs with positive implications for better understanding the tsunami generation mechanisms and the assessment of tsunami hazards and risks. [ABSTRACT FROM AUTHOR]

Knowledge of post-larval swordfish (Xiphias gladius) ecology in the world's oceans is incomplete as they are rarely found in ichthyoplankton samplings or commercial catches and individuals are difficult to observe in the marine ecosystem. Analyses of stomach contents of apex predators can provide otherwise unobtainable ecological insights. Two well-preserved bills of post-larval swordfish were identified among the partially digested stomach contents of an adult male dolphinfish (Coryphaena hippurus) caught in the northern Tyrrhenian Sea. The lower jaw to fork lengths of the two predated swordfish were estimated at, respectively, 18 and 22 cm, corresponding to 81- and 99-day-old swordfish hatched in the 2022 spawning season. This analysis and recent information on the reproductive dynamics of swordfish in the same area reported in the literature shed light not only on the early stages of swordfish growth but also on dolphinfish ecology in the Tyrrhenian Sea. The two species share the same habitat and are both caught with commercial pelagic surface longlines. Environmental shifts associated with climate change could unpredictably modify the reproduction dynamics, growth, recruitment and distribution of both species. This knowledge is important for the sustainable management of regional fisheries. [ABSTRACT FROM AUTHOR]

Marine Protected Areas (MPAs) are vital for biodiversity conservation, yet their effectiveness in preserving foundation seaweeds remains understudied. This study investigates the diversity and distribution of Cystoseira sensu lato (including Cystoseira, Ericaria, and Gongolaria, hereafter referred to as Cystoseira s.l.) populations in an MPA located in the central Mediterranean Sea, comparing them with those in two unprotected sites. We hypothesized MPA Cystoseira s.l. populations would display higher diversity and structure compared to outside unprotected sites. Results revealed a total of 19 Cystoseira s.l. species at depths of 0–20 m, with the MPA exhibiting a higher diversity than unprotected sites. Thus, MPAs can play a crucial role in fostering the diversity of Cystoseira s.l. populations. However, no significant differences were observed among the MPA's protection zones, raising questions about the zoning effectiveness. Additionally, our survey uncovered a substantial presence of non-indigenous seaweeds within the MPA. In conclusions, while MPAs improved Cystoseira s.l. diversity compared to unprotected sites, the varying efficacy of protection within MPA zones suggested a necessity for site-specific conservation strategies. The presence of non-indigenous seaweeds emphasizes ongoing challenges. This study provides a baseline for understanding Cystoseira s.l. population dynamics, crucial for future monitoring and conservation efforts in the face of global change. [ABSTRACT FROM AUTHOR]

The Oceans from Space V Symposium, held in Venice, Italy, on 24–27 October 2022, devoted special sessions to sea level rise, as described by a series of satellite altimeters, and to remediations of consequent calamities in vulnerable mediterranean seas. It emerged that various aspects of climate change can be modelled in time as a Single Exponential Event (SEE), with a similar trend (a 54–year e–folding time) for CO2 concentration in the Earth's atmosphere, global average sea surface temperature, and global average sea level. The sea level rise record, combining tide gauges data starting in 1850, as well as more recent altimeter data, for the last 30 years, is already 25 cm above historical values. If the curve continues to follow the exponential growth of the simple SEE model, it will reach about 40 cm by the year 2050, 1 m by 2100, and 2.5 m by 2150. As a result, dramatic impacts would be expected for most coastal areas in the next century. Decisive remediations, based on geo-engineering at the basin scale, are possible for semi-enclosed seas, such as the Mediterranean and Black Seas. Damming the Strait of Gibraltar would provide an alternative to the conclusion that coastal sites such as the City of Venice are inevitably doomed. [ABSTRACT FROM AUTHOR]

Decapod crustaceans are important components of the fauna of soft-bottom habitats. In this work, the records of decapod crustaceans are provided through the analysis of a large soft-bottom benthic macroinvertebrates dataset of the Central Mediterranean Sea. Decapod crustacean assemblages were collected in the last twenty years by a Van Veen grab in 42 study sites located along the Italian coasts at depths ranging from 1 up to 120 m. The spatial distribution of the crustaceans examined, which include 120 species belonging to 40 families, was investigated according to the biogeographical zones identified in the Italian seas. The spatial distribution of 36 species was updated, comparing the ISPRA decapod crustacean dataset with the most recent Italian checklists. For the species updated, the number of specimens, the year and season of sampling, and environmental data, such as the bathymetric range and habitat details, are provided for each site investigated. Data are discussed and compared with the existing literature, also referring to what is reported in the World Register of Marine Species (WoRMS), with the aim of contributing to the knowledge of the biodiversity of the marine species and supporting the updating of checklists and registers in the Mediterranean Basin. [ABSTRACT FROM AUTHOR]

The gill tissue of bivalve mollusks hosts rich symbiotic microbial communities that may contribute to host health. Spondylus spinosus is an invasive Lessepsian oyster in the Eastern Mediterranean Sea that has become highly abundant while constantly expanding its range northwestward. Using 16S rRNA gene amplicon sequencing, we examined how temperature affects S. spinosus oysters and their gill microbiota in a series of experiments: exposing them to the current annual seawater temperature range, to the colder temperature of the Western Mediterranean Sea, and to the elevated temperature as predicted under global warming scenarios. The bacterial genus Endozoicomonas dominated the communities of the S. spinosus, mainly upon exposure to winter-like (16 °C) temperatures. Exposure to the elevated seawater temperature resulted in a significant change in the bacterial communities, while the oysters maintained normal functioning, suggesting that the oyster may survive a seawater warming scenario. Exposure to 11 °C led to the health deterioration of the oysters, the emergence of opportunistic pathogens, such as Arcobacter, Vibrio, Colwelliaceae, and Pseudoalteromonas, and a decline in the relative abundance of Endozoicomonas, suggesting that S. spinosus might not survive Western Mediterranean Sea winters. Both the host and its gill bacteria are thus greatly affected by temperature, which could consequently restrict the range of expansion of this and other invasive oysters. [ABSTRACT FROM AUTHOR]

In the Mediterranean Sea, and in marine areas worldwide, for most locations, data on species presence and abundance are generally poor or non-existent. When available, these data are generally reported only at small scale and/or for short temporal series. In this study, the investigation of abundance and size trends, along with some ecological aspects of the data-poor species Scorpaena porcus, commonly known as the Black Scorpionfish, was undertaken using FEK (Fishers' Ecological Knowledge). The results clearly indicated a sharp reduction in both abundance and size over the last 21 years (2001–2021) of this species in the central Mediterranean Sea. The causes of this decline, and the importance of FEK, as well as Local Ecological Knowledge (LEK), in research and the assessment and management of biological resources are discussed. [ABSTRACT FROM AUTHOR]

Simple Summary: Octocorals are marine ecosystem engineers that can form dense patches on rocky substrates. These organisms enhance the three-dimensional complexity of the habitat and provide several ecological services within and around their canopy. Mapping their distribution and understanding the intra- and inter-specific processes that drive population dynamics is of crucial importance. In this study, we investigated via Remotely Operated Vehicle the distribution and demography of two hard-bottom octocorals that share similar habitat preferences within the Western Mediterranean: the yellow gorgonian Eunicella cavolini and the precious red coral Corallium rubrum. We tested for possible mutual influences of the two species when co-occurring. Here, we show that for both species, populations dwelling in deeper habitats show demographic features of immature or disturbed populations, possibly due to environmental and/or anthropogenic disturbances that occur locally. Moreover, the density of one species is significantly positively correlated to that of the other, but not influenced by the colony morphology (e.g., height) of the other species. We encourage further studies that might contribute to shedding light on inter-specific relations occurring in these vulnerable ecosystems. Corallium rubrum and Eunicella cavolini are two octocorals, reported as co-occurring species in the deep rocky habitats of the Mediterranean Sea with a high hydrodynamic and moderate eutrophication. Their spatial distribution and demography in the deep sea are mainly affected by temperature and direct and indirect anthropogenic activities; however, knowledge of the factors that potentially influence their co-existence is scarce. This paper provides novel data on the distribution and demography of these two species, at depths between 50 and 290 m in the Western Mediterranean Sea, providing insights on their co-occurrence. Both species exhibited the highest population density at deeper sites (>150 m), showing an inverse size–density relation. Density values ranged from 0.03 colonies m−2 to 32 and 80 col. m−2 for yellow gorgonian and red coral, respectively. The two species co-occurred in 13% of the total frames examined, mostly dwelling between 120 and 160 m depth. Distance-based linear modeling (DistLM) emphasized that when co-occurring the variability of the two species' densities were significantly driven by the density—rather than the morphology (i.e., height)—of the other species. We stress the need for further studies to elucidate the possible mutual effects of suspension feeders and to test the role of different environmental factors potentially influencing inter-specific relationships. [ABSTRACT FROM AUTHOR]

Coastal ecosystems and anthropic activities are prone to be affected by the negative impact of marine-related processes induced by climate change, such as erosion, flooding and permanent inundation. Studies aiming at defining potential risk scenarios represent a valuable tool for the identification of the most suitable coastal adaptation measures. After outlining sea level rise implications at the Mediterranean scale, this paper deals with inundation risk scenarios for the years 2050 and 2100 for the north-eastern sector of the Island of Gozo (Malta), central Mediterranean Sea. The analysis, carried out by applying an index-based procedure, firstly required the evaluation of the susceptibility to inundation of the investigated coastal stretch under different sea level projections. Then, the spatial combination of inundation susceptibility with the exposure and vulnerability of the area allowed identification of the most critical sectors in terms of coastal risk. The results of the analysis showed that, under the worst-case climate scenarios, 5.5% and 8.1% of the investigated coastal sector are prone to very high inundation risk (Class R4) in 2050 and 2100, respectively. In particular, the bays of Ramla and Marsalforn, which are characterized by significant economic and touristic activities, were found to be the sites where the expected impacts of future sea level rise will be higher if no management strategy and adaptation action are taken in the near future. [ABSTRACT FROM AUTHOR]

Marine pharmacology is an exciting and growing discipline that blends blue biotechnology and natural compound pharmacology together. Several sea-derived compounds that are approved on the pharmaceutical market were discovered in sponges, marine organisms that are particularly rich in bioactive metabolites. This paper was specifically aimed at reviewing the pharmacological activities of extracts or purified compounds from marine sponges that were collected in the Mediterranean Sea, one of the most biodiverse marine habitats, filling the gap in the literature about the research of natural products from this geographical area. Findings regarding different Mediterranean sponge species were individuated, reporting consistent evidence of efficacy mainly against cancer, infections, inflammatory, and neurological disorders. The sustainable exploitation of Mediterranean sponges as pharmaceutical sources is strongly encouraged to discover new compounds. [ABSTRACT FROM AUTHOR]

Simple Summary: When species from one place invade and settle in another, it can cause serious problems for the local environment. These invasions, known as bio-invasions, disrupt natural ecosystems and can lead to major changes. The Mediterranean Sea is especially at risk because the water conditions are changing rapidly due to climate change, which, coupled with the opening of the Suez Canal, creates an appropriate environment for species from the Red Sea to move in. In May 2023, divers found a type of soft coral called Dendronephthya, that is new to the Mediterranean Sea near Israel. This coral is normally found in the Indo-Pacific region and is common in the Red Sea. Using molecular and morphological analysis, we confirmed the identity of the coral. Because this coral can attach swiftly to surfaces and grow quickly, it is expected to spread rapidly and become more common throughout the Mediterranean Sea. Bio-invasions have the potential to provoke cascade effects that can disrupt natural ecosystems and cause ecological regime shifts. The Mediterranean Sea is particularly prone to bio-invasions as the changing water conditions, evoked by climate change, are creating advantageous conditions for Lessepsian migrants from the Red Sea. Recently, in May 2023, a new alien species was documented in the Mediterranean Sea—a soft coral of the genus Dendronephthya. This discovery was made by divers conducting 'Long-Term Ecological Research' surveys, along the coast of Israel, at a depth of 42 m. Genetic and morphological testing suggest that the species identity may be Dendronepthya hemprichi, an Indo-Pacific coral, common in the Red Sea. According to life history traits of this species, such as accelerated attachment to available surfaces and fast growth, we expect it to rapidly expand its distribution and abundance across the Mediterranean Sea. [ABSTRACT FROM AUTHOR]

In the Mediterranean Sea, two critical issues affect marine benthic biocenosis: sedimentation and the increasing trend in marine biodiversity loss. These processes are very marked along the western side of the Calabrian coastline, where siltation is one of the main reasons for the regression of Posidonia beds in the regional coastal waters. This study investigates the relationships between the geomorphological features of the debris source areas, represented by fluvial basins, and the distribution of Posidonia meadows. So, a concise geomorphological study of the Tyrrhenian fluvial basins with an area greater than 200 km2 was carried out, and we correlated the results with the mapping of the meadows in Calabria's Tyrrhenian waters. Furthermore, to assess the increased level of burial in a Posidonia oceanica meadow and its health state over time, a program of Posidonia monitoring was undertaken between 2000 and 2010 in a test area located in the Marine Regional Park of Isca (Calabria, Southern Italy). The results of this survey highlighted that, at the beginning of the study period, the silting rate of 4–5 cm/year saw the meadow suffer a reduction in its photosynthetic ratio with a mortality rate of 50%. The siltation rate reached 12 cm/year in 2010, and the meadow began to disappear. Therefore, marine pollution via sedimentation represents a serious factor in the regression of Posidonia oceanica meadows and enhances the risk of a gradual loss of marine biodiversity. [ABSTRACT FROM AUTHOR]

A Lagrangian model which simulates the transport of radionuclides released from nuclear accidents in the western Mediterranean Sea was recently described. This model was developed in spherical coordinates and includes three-dimensional mixing due to turbulence, advection by currents, radioactive decay, and radionuclide exchanges between water and bed sediments. Water circulation was downloaded from the HYCOM global ocean model. Water–sediment interactions were described using a dynamic model based on kinetic transfer coefficients. Mixing, decay, and water–sediment interactions were solved using a stochastic method. Now, a dynamic biological uptake model consisting of four species (phytoplankton, zooplankton, non-piscivorous fish, and piscivorous fish) has been integrated within the transport model to be able to assess the effects of a potential accident in biota and fishery regions. The model has been set up for 137 Cs and 90 Sr due to the radiological relevance of these radionuclides. Several hypothetical accidents were simulated, resulting in 137 Cs concentrations in biota significantly higher than background levels. In contrast, 90 Sr accumulates in the food chain to a considerably weaker extent. [ABSTRACT FROM AUTHOR]

Simple Summary: Fish Aggregating Devices (FADs) are floating structures used to create shadows and aggregate pelagic fish. In tropical and subtropical waters, the dangerous impact of these structures, due to high levels of bycatch, is well known. We report the first case of a cetacean killed by a FAD and stranded on the coast of Lazio, Italy (central Tyrrhenian Sea). The postmortem evaluation, the difference in degradation (necrosis) between the tail and peduncle, and the marked malnutrition confirm that this specimen was still alive at the time of entanglement. Although this is the first verified case of a cetacean entangled in a FAD in Mediterranean waters, given the widespread use of illegal versions of these devices, the extent of the problem may be greatly underestimated. Fish Aggregating Devices (FADs) are anchored floating structures often made with cheap scrapped materials and used to aggregate pelagic fish species under their artificial shadows. Globally, the dangerous impact of FADs is well known. They pose a severe threat as a source of bycatch, as a danger to navigation, and with their high potential to become marine litter. Unintended entanglement and consequent mortality in FADs of vulnerable (e.g., sharks, sea turtles, and cetaceans) and commercial species is a serious concern for several international inter-governmental bodies (e.g., EU, GFCM, and IWC). This work describes the first case of a cetacean, a striped dolphin (Stenella coeruleoalba), entangled in a FAD in the Mediterranean Sea. A young male of striped dolphins was found dead along the coast of Lazio (central Tyrrhenian Sea) with its peduncle entangled in typical debris from illegal/artisanal FADs (i.e., a nylon rope, teared gardening plastic sheets, bush branches, and scrapped empty plastic bottles). Although this is the first confirmed case of a cetacean entangled in a FAD in Mediterranean waters, given the extent of the deployment of anchored FADs, the scale of this type of interaction with protected species might be seriously underestimated. Therefore, actions and monitoring need to be implemented urgently to effectively protect and conserve marine biodiversity. [ABSTRACT FROM AUTHOR]

Mass mortality events and anthropogenic impacts affecting Paramuricea clavata (Risso, 1826) have been increasingly documented during the last decades. These impacts have enhanced the settling of epibiont organisms on injured colonies. This epibiosis was studied using photographic sampling carried out on the granitic outcrops of the Tavolara Channel within the Tavolara–Punta Coda Cavallo marine-protected area (NE Sardinia) between 2017 and 2023 at 35–55 m. The number of colonies and percentage of surface involved in the epibiosis, the specific richness of the epibiont community, and the temporal evolution of the phenomenon were studied. Almost all the investigated gorgonians (93%) showed parts involved in epibiosis, with high percentages of surface covering (one-third of the surface). Out of the 37 epibiont species recorded, the most recurrent ones demonstrated an ecological succession dominated by Hydrozoa, Porifera, Bryozoa, Serpulidae, and the parasitic soft coral Alcyomiun coralloides. Nevertheless, single colonies studied over time revealed the unpredictability of the colonization process. The peculiar habitat of the granitic outcrops hosting the P. clavata forests is of a high naturalistic value and demonstrates a widespread condition of suffering, supported by both environmental and anthropogenic sources of stress. Such considerations make it necessary to review the current zonation of the area, where the actual vulnerability and usability evaluations are based on incomplete information. [ABSTRACT FROM AUTHOR]

The worldwide diffused bubble snails, Haminoeidae, although characterized by an extreme morphological homogeneity, display the most diverse radiation inside the order Cephalaspidea. This hidden diversity within the family Haminoeidae was recently unraveled by molecular studies, which helped to understand the evolutionary history of this group by clarifying some aspects of its systematics. In fact, the type genus Haminoea W. Turton and Kingston (1830) was proved to be polyphyletic and, consequently, the genus Haminoea sensu stricto was restricted to the Mediterranean, Atlantic and East Pacific species, with the Mediterranean Haminoea hydatis Linnaeus (1758) as the type taxon. However, at the specie rank, many aspects need to be clarified, especially concerning the Mediterranean fauna. Due to low reliability of macro-morphological characters, the minimal quantity of molecular data currently available on Mediterranean specimen adds to the lack of molecular comparison in most reports. Based on such considerations, Haminoea species from an interesting Mediterranean study area, Faro Lake, a Sicilian coastal lake that is considered a hot spot for both alien and endemic marine Heterobranchia, have been studied using an integrative taxonomic approach. Eleven Mediterranean specimens belonging to four Haminoea bubble snails have been collected, identified and compared with samples from other localities, integrating ecological, morphological, anatomical (reproductive apparatus) and molecular data. Based on molecular investigations carried out on three different molecular markers (H3, 16S and COI), the morphological identifications of the species collected in the Faro Lake have been confirmed, and 37 new sequences are provided for future comparisons. Furthermore, results from this integrative systematic study shed light on the phylogenetic relationships occurring in this group of bubble snails that could be useful in identifying valid diagnostic morphological characters. Haminoea hydatis and H. navicula were confirmed to be close to each other, with H. orteai as sister to them and with H. orbignyana as the basal taxon. Given external morphological features are unreliable with species identification in Haminoea genus open questions on the geographical distribution of the species and on their ranges of intraspecific variability have yet to be addressed and further in-depth studies are needed. Finally, the presence of three sympatric Haminoea species, two of which are considered native or long-time naturalized, along with other occasional congeneric species, and the absence of the introduced invasive Haloa japonica, reflects both the resilience and stochastic space-temporal dynamics of Faro Lake. This confirms it as an inexhaustible source of case-studies. [ABSTRACT FROM AUTHOR]

Biological invasions are widely recognized as a major threat to native biodiversity, ecosystem functioning and services. Non-indigenous species (NIS) may in time become invasive (invasive alien species (IAS)), determining significant environmental, socioeconomic and human health impacts such as biodiversity loss and ecosystem service degradation. The Mediterranean islands, particularly Sicily and the circum-Sicilian islands (northwestern Mediterranean Sea), which are important hotspots of biodiversity, are notably vulnerable to anthropogenic pressures such as biological invasions. Therefore, monitoring NIS distribution as well as understanding their effects on native biodiversity is critical in these areas for planning effective conservation strategies. Here, we report four different case studies from Sicily that highlight how NIS may affect native biodiversity and habitats. The first three case studies were carried out within Marine Protected Areas (MPAs) and highlight (1) the ability of Caulerpa cylindracea to promote the establishment of other NIS, including biofouling worms belonging to the genus Branchiomma; (2) how the shift in habitat from the native Ericaria brachycarpa to the invasive Asparagopsis taxiformis may drastically erode the primary producer biomass and associated biodiversity; and (2) that the presence of Lophocladia lallemandii can affect the molluscan assemblage inhabiting the canopy-forming Gongolaria montagnei. The fourth case study, performed along the northwestern coast of Sicily, shows how Halophila stipulacea can affect the growth of the co-occurring native seagrass Cymodocea nodosa. Overall, these case studies demonstrate various ways in which NIS can interact with native biodiversity and habitats. Furthermore, they emphasize that MPAs are ineffective at preventing the introduction and spread of NIS. [ABSTRACT FROM AUTHOR]

A detailed review of wave energy resource assessment and the state-of-the-art of deployed wave energy converters (WECs) in real environmental conditions in the Mediterranean Sea have been analysed in this study. The installed power of the several deployed WECs in the Mediterranean Sea varies between 3–2500 kW. Ten project cases of deployed WECs in the basin are presented, with their analysis of the essential features. Five different types of WEC have already been tested under real environmental conditions in Italy, Greece, Israel and Gibraltar, with Italy being the Mediterranean country with the most deployed WECs. The main questions of the relevant studies were the ongoing trends, the examination of WECs in combination with other renewable sources, the utilising of WECs for desalination, and the prospects of wave energy in the Mediterranean islands and ports. This paper is the first comprehensive study that overviews the recent significant developments in the wave energy sector in the Mediterranean countries. The research concludes that the advances of the wave energy sector in the Mediterranean Sea are significant. However, in order to commercialise WECs and wave energy exploitation to become profitable, more development is necessary. [ABSTRACT FROM AUTHOR]

The aims of the present paper were to review the knowledge about the Mediterranean non-indigenous species of the taxa Cnidaria and Ctenophora (CC NIS), to screen the risk of 98 species for their potential invasiveness in the Mediterranean Sea and their approach to the Italian waters. Of these, 38% are well established in the basin, 4% are known for their invasiveness, 44% are casual, 11% have a taxonomic status unresolved, and 3% are included in the category "cryptogenic". The biodiversity CC NIS of the Mediterranean Sea has changed considerably in the last two decades and 27 out of 98 Mediterranean CC NIS are present in the Italian waters. Fifteen CC NIS, some equipped with high invasive potential, should be regarded as good candidates to become future immigrants of the Italian waters. Anticipatory NIS forecast based on biogeographical and ecological analyses may provide a useful tool for targeted management of the CC NIS issue and for the assessment of the second descriptor of Good Environmental Status. On the other hand, conservation and management of marine ecosystem should be based on the conservation of the essential environmental conditions for the functioning of these ecosystems instead of the contamination or eradication of alien species. [ABSTRACT FROM AUTHOR]

Simple Summary: The shrimp Penaeus aztecus, native to the western Atlantic, was first reported in the Mediterranean Sea (Bay of Antalya, Southern Turkey) in 2010. In the following years, it proved its invasiveness with multiple records from all over the Mediterranean except the westernmost sector and the North Adriatic Sea. Several pieces of evidence suggest that the unintentional transport of larvae in the ballast waters of transoceanic vessels departing from the U.S. West Coast, instead of the escape of adults from unreported experimental shrimp farming, is the more likely pathway of the introduction of P. aztecus in the Mediterranean Sea. The accurate scrutiny of scientific literature on non-indigenous species brought to light an earlier (2005) arrival in the Black Sea, which passed unnoticed as the shrimps were misidentified as Penaeus semisulcatus, also a non-indigenous species, which is established and exploited in the Levant Sea since 90 years. But it is native to the Indo-Pacific region, other misidentifications were also found, therefore morphological characters allowing correct identification of the two species and of the autochthonous Penaeus kerathurus are illustrated. Non-indigenous species are among the descriptors adopted in the Marine Strategy Framework Directive for determining the good environmental status of marine waters in the European States, hence the importance of their correct identification. The shrimp Penaeus aztecus, native to the western Atlantic, was first reported in the eastern Mediterranean Sea in 2010. New records, from different Mediterranean localities, multiplied in the following years. The accurate search of the literature on non-indigenous species discovered it was misidentified more than once as another alien shrimp, P. semisulcatus, native to the Indo-Pacific region, with the result that its earlier presence in the Black Sea went unnoticed. Morphological characteristics allowing the identification of these two species, the autochthonous P. kerathurus and two other alien Penaeus species present in the Mediterranean, are reprised. The present distribution of P. aztecus based on literature records and surveys carried out in the northern and central Adriatic between 2016 and 2021 is mapped. The unintentional transport of larvae carried in ballast water by transoceanic vessels departing from the U.S. East Coast is suggested as the most probable introduction pathway. The significance of the correct identification of non-indigenous species, a "Descriptor" adopted in the Marine Strategy Framework Directive for determining the good environmental status of marine waters in the European States, is emphasized. [ABSTRACT FROM AUTHOR]

Clean energies are being incorporated into the energy mix in numerous countries. Through a spatial survey of maritime trade, restricted military maritime areas, marine planning, and the presence of fauna and flora along the Ligurian Sea, locations for possible investments in wave energy harvesting were identified in the Northern Thyrrenian Sea, along the Ligurian coast. Previous studies in this region have demonstrated, at a lower spatial resolution, the wave energy potential that can be captured and its variation over time. However, the optimization of wave energy exploitation under the criteria of the functionality and safety of converter devices has not yet been evaluated in the Ligurian Sea. The purpose of this study is to identify the optimal wave energy converter from an economic and technical perspective at several selected locations in the Ligurian Sea. This study involves the scaling of the employed power matrices to obtain the optimized capacity factors of wave energy converters. [ABSTRACT FROM AUTHOR]

The age and growth of the blackspot seabream, Pagellus bogaraveo, were determined by examining sagittal otoliths from fish sampled in the eastern Adriatic Sea. A total of 674 specimens (181 males, 90 hermaphrodites, 108 females, and 295 immatures) ranging from 8.80 to 47.27 cm (21.93 ± 9.00 cm) in total length were analyzed. The maximum observed age for the whole sample was 13 years. The sample was dominated by 1-year-old specimens as a consequence of an abundance of juvenile specimens collected by beach seines. Growth was described by the von Bertalanffy growth curve (L∞ = 52.3 cm, K = 0.15 year−1, t0 = 0.49 year, R2 = 0.97), and the growth performance index (Φ') was 2.61. The length, width, thickness, and mass of the otoliths were compared with the total length and age of P. bogaraveo from the eastern Adriatic. The analysis showed that the measures were adequate predictors of age. These results can be of value for more effective management measures aimed at the conservation of this species. [ABSTRACT FROM AUTHOR]

The tintinnid ciliate Rhizodomus tagatzi has spread rapidly in recent decades in neritic areas of the Mediterranean and adjacent seas, where it is classified as a non-indigenous species. The present study documents the first finding of the species in the Adriatic Sea, in the transitional waters of the Neretva River estuary. Zooplankton material was collected with 5 L Niskin bottles in three layers (1, 5 and 7 m) at two stations, at the mouth of the Neretva River and 16 km upstream, in the period from May 2022 to January 2023. In addition to the morphological characteristics of R. tagatzi, we discuss the state and variability of the populations based on the abundance of the species and the influence of abiotic environmental factors (temperature and salinity) and possible pathways of entry into the Adriatic Sea. The maximum abundance of R. tagatzi in the Neretva River estuary of ~2 × 103 cells L−1 is among the highest in the Mediterranean Sea, and the species has a significant contribution to the tintinnid community (>80%), indicating successful establishment of the population in the estuary and intense influence on ecosystem functioning until the strong river flow completely displaces the wedge from the seabed. Statistical methods confirm the differences between stations in the total abundance of tintinnids and differences in their vertical distribution at the upstream station. [ABSTRACT FROM AUTHOR]

Observing the ocean provides us with essential information necessary to study and understand marine ecosystem dynamics, its evolution and the impact of human activities. However, observations are sparse, limited in time and space coverage, and unevenly collected among variables. Our work aims to develop an improved deep-learning technique for predicting relationships between high-frequency and low-frequency sampled variables. Specifically, we use a larger dataset, EMODnet, and train our model for predicting nutrient concentrations and carbonate system variables (low-frequency sampled variables) starting from information such as sampling time and geolocation, temperature, salinity and oxygen (high-frequency sampled variables). Novel elements of our application include (i) the calculation of a confidence interval for prediction based on deep ensembles of neural networks, and (ii) a two-step analysis for the quality check of the input data. The proposed method proves capable of predicting the desired variables with relatively small errors, outperforming the results obtained by the current state-of-the-art models. [ABSTRACT FROM AUTHOR]

Cystoseira s.l. forests are recognised as important habitats which host diverse coastal fish assemblages. Many fish species use such habitats as feeding, breeding, and nursery grounds. Since the coastal fish community depends on the availability of dense macroalgal belts, the decline of these habitats in the Mediterranean Sea also affects the density of coastal fish species. We studied the coastal fish assemblage in Cystoseira s.l. forests in three consecutive years 2019–2021 in the Gulf of Trieste (Adriatic Sea). Data on coastal fish fauna were collected by visual counts conducted by SCUBA diving. Data on algal cover and habitat types were obtained by recording with a video camera. Similarities and differences in the fish community were analysed in terms of habitat and substrate preferences. A total of 34 species were recorded in Cystoseira forests. The results of the present study show that the different algal cover and associated depth gradient have different effects on the fish assemblage in coastal waters, affecting species composition and abundance. For many species, particularly labrids and sea breams, there is a decreasing temporal trend in frequency of occurrence and density. However, fish community trends can be used as a good "proxy" to evaluate the algal belt status. Our results indicate that rapid conservation and restoration actions are needed to stem the decline of Cystoseira s.l. forests. [ABSTRACT FROM AUTHOR]

While many current and potential uses of the Israeli Mediterranean Sea have clearly defined the economic value and apparent benefits to various stakeholders (e.g., energy and raw materials extraction and maritime traffic), the benefits of these local marine ecosystems are still severely underexplored and are not manifested in economic terms. Coupled with ongoing environmental deterioration such as overfishing, climate change, and biological invasion, the need for performing monetary valuations of the benefits derived from this ecosystem is clearly evident. In this study, we evaluated three marine and coastal ecosystem services, namely, food provisioning, wastewater treatment, and coastal protection, in order to better quantify and map their importance to society. Food provisioning was inspected through the fishing sector, and its benefits were analyzed using the bioeconomic model. The results recommend a reduction in fishing efforts to increase overall biomass levels of both local and invasive fish species. However, this may lead to an economic loss in fishery profits due to reduced catch levels. The economic valuation of wastewater treatment as an ecosystem service hint at possible thresholds governed by effluent volumes and environmental conditions, whereby exceedance of Good Environmental Status (GES) standards may lead to a reduction of ~25% in the potential benefit of this ecosystem service. Finally, this study proposes an engineering restoration solution for compromised intertidal abrasion platforms, with estimated costs and potential benefits for the conservation of at-risk areas. The annual economic value of this ecosystem service is NIS 65–209 million (EUR 16.2–52.2 million). [ABSTRACT FROM AUTHOR]