Monitoring the genetic diversity in holothurian populations from the Italian coasts with mitochondrial DNA sequences.

Sea cucumbers are deposit feeding members of marine benthic communities. The over-exploitation of sea cucumber natural stocks, especially in the Mediterranean basin, is having negative impacts on the marine ecosystem. This concerns had led the Italian government to take legal actions to preserve these important marine resources. The aim of this study was to evaluate the level of genetic diversity and population structures within two sympatric Holothuria sea cucumber species, H. polii and H. tubulosa, across ten Mediterranean areas along Italy. A 323 bp portion of the COI mitochondrial gene was sequenced in a total of 441 holothurians (251 H. polii, 177 H. tubulosa and 13 from other species). Genetic diversity analyses and analysis of molecular variance (AMOVA) suggest that H. polii and H. tubulosa species are distinct, but within and among populations are homogeneous, indicating active gene flows across the Mediterranean areas investigated. H. polii showed a lower genetic diversity than H. tubulosa, probably related to differences in life history traits. Phylogenetic analyses showed a clear differentiation between the two species, even if six specimens morphologically assigned to a species clustered within the other species, indicating a possible occurrence of hybridization events. These data will be useful in implementing conservation actions for these holothurian genetic resources.

Atlantic bluefin tuna tagged off Norway show extensive annual migrations, high site-fidelity and dynamic behaviour in the Atlantic Ocean and Mediterranean Sea.

Atlantic bluefin tuna (ABFT; Thunnus thynnus) is a highly migratory species. To investigate the migrations and vertical behaviours of ABFT migrating to Nordic waters, we deployed pop-up satellite archival transmitting tags on 25 ABFT off Norway (curved fork length: 228-292 cm). We obtained 16 full-year migrations, which differed between individuals, and physically recovered 13 tags, which provided 4699 days of archival depth and temperature data. ABFT occupied waters from the Arctic Circle to as far south as Cabo Verde, Africa, and occupied depths down to 1190 m and temperatures from 0.5 to 27.8°C. During their annual migrations, ABFT spent, on average, 68 days in Norwegian waters, 65 days in the Newfoundland Basin, 35 days around the Canary Islands and 33 days in the West European Basin. Most ABFT entered the Mediterranean Sea with a mean entry date of 13 May and visited known spawning grounds, staying, on average, 44 days. All ABFT with full-year deployments returned to Norwegian waters. ABFT displayed high site-fidelity and dynamic vertical diving behaviours that varied between hotspots and seasons. These spatiotemporal data provide important ecological knowledge for sustainable management and the conservation of the recently recovered eastern ABFT stock.

Domesticating the wild through escapees of two iconic mediterranean farmed fish species.

Extractive fisheries and marine aquaculture share space and target species. Several regional-scale examples exist of escapees entering wild fisheries landings, yet no study has assessed the influence of aquaculture on landings at an ecosystem scale. We examined the effects of farmed fish escapes on fisheries using FAO data and published escape rates for Gilthead seabream (Sparus aurata) and European seabass (Dicentrarchus labrax). Seabream landings were significantly correlated with the estimated biomass of escaped seabream entering the wild. There was a similar pattern for seabass until 2005, but the overall relationship between landings and escapes was not significant due to the dramatic drop in catches in recent years. We argue that seabass escapees' relatively high mortality, lower capturability, and minor 'leaking' from farms may obscure their influence on landings. Significant positive fisheries regime shifts were detected for both species, matching the onset of aquaculture in the Mediterranean and the period when escapees from aquaculture surpassed landings. Our results suggest that fish escapes of these two iconic species may mask wild stock overexploitation, confound stock assessments, alter genetic diversity, increase the risk of spreading pathogens and parasites, and compete with wild conspecifics while boosting fisheries landings.

How much do we know about the microplastic distribution in the Mediterranean Sea: A comprehensive review.

The Mediterranean Sea is one of the most heavily polluted regions. Here we comprehensively review the current state of microplastic pollution in the Mediterranean Sea and the Black Sea. A total of 284 studies published between 2012 and 2023 were analyzed, revealing a continuous increase in research efforts. Our review encompassed microplastic monitoring studies across five environmental matrices: the sea surface, water column, intertidal sediment, bottom sediment, and biota, with a predominant focus observed in biota-related studies with fish, molluscs, crustaceans, and echinoderms being the primary focus. The study found that species such as Mullus barbatus, Mytilus galloprovincialis, Nephrops norvegicus, and Holothuria tubulosa are frequently studied species. The review also emphasizes the lack of standardized methodologies across studies, which hampers the comparability of results and the synthesis of data. The findings of this study provide a critical evaluation of the current research landscape and identify significant knowledge gaps, particularly in the underrepresented southern Mediterranean and Black Sea regions, calling for more balanced research efforts and methodological consistency in future studies.

Modeling the dispersion of wastewater pollutants in Gaza's coastal waters.

The disposal of sewage water in Gaza City has emerged as a significant issue with extensive environmental repercussions. This study seeks to investigate the pollution plume resulting from the discharge of untreated or partially treated sewage water through Gaza City's main outlet into the Mediterranean Sea. Additionally, it aims to predict scenarios for various design configurations of submerged outfalls with either single-port or multi-port diffusers and compare these scenarios against the Environmental Protection Agency (EPA) recreational water quality criteria. According to the EPA, the concentration of Enterococci bacteria at the edge of the mixing zone should not exceed 35 CFU/100 ml to minimize the adverse environmental impact on the marine ecosystem. CORMIX software was utilized as a modeling tool to simulate the dispersion and attenuation behavior of pollutants resulting from this process and to conduct a sensitivity analysis to optimize the design configuration of the sewage disposal system. The simulation considered the influence of ambient conditions (ambient velocity, wind, and seawater density), effluent characteristics (density, flow rate, pollutant concentration, and pollutant decay rate), outfall configuration, and sea bathymetry. Simulation results indicate that a single-port diffuser is unsuitable according to EPA recreation standards. Multi-port unidirectional diffusers, extending 490 m from the shore into the water, meet the required standards. To a lesser extent, the multi-port staged distributor also meets the standards and is more recommended for counter-current situations.

Herpesvirus surveillance in stranded striped dolphins (Stenella coeruleoalba) and bottlenose dolphins (Tursiops truncatus) from Italy with emphasis on neuropathological characterization.

Herpesvirus (HV) is widely distributed among cetacean populations, with the highest prevalence reported in the Mediterranean Sea. In this study, a comprehensive analysis was conducted, including epidemiological, phylogenetic, and pathological aspects, with particular emphasis on neuropathology, to better understand the impact of HV in these animals. Our results show a higher presence of HV in males compared to females, with males exhibiting a greater number of positive tissues. Additionally, adults were more frequently affected by HV infection than juveniles, with no infections detected in calves or neonates. The affected species were striped (Stenella coeruleoalba) and bottlenose dolphins (Tursiops truncatus). The highest positivity rates were observed in the genital system, cerebrum, and skin tissues. Phylogenetic analysis indicated a higher occurrence of Gammaherpesvirus (GHV) sequences but increased genetic diversity within Alphaherpesvirus (AHV). Key neuropathological features included astro-microgliosis (n = 4) and meningitis with minimal to mild perivascular cuffing (n = 2). The presence of concurrent infections with other pathogens, particularly cetacean morbillivirus (CeMV), underscores the complex nature of infectious diseases in cetaceans. However, the presence of lesions at the Central Nervous System (CNS) with molecular positivity for GHV, excluding the involvement of other potential neurotropic agents, would confirm the potential of this HV subfamily to induce neurological damage. Pathological examination identified lesions in other organs that could potentially be associated with HV, characterized by lymphoid depletion and tissue inflammation. These findings enhance our understanding of HV in odontocetes and highlight the need for ongoing research into the factors driving these infections and their broader implications.

SARS-CoV-2 molecular surveillance of migrant populations arriving to Italy via the Mediterranean Sea: lessons learnt.

Refugees and migrants remain one of the most vulnerable people and the COVID-19 pandemic has posed additional challenges both in terms of increased risk of infection and death experienced, highlighting existing inequities in access to and utilization of health services, as underlined by World Health Organization in 2020 in the Health and Migration Programme. In the context of the Programme 'Epidemiological surveillance and control of COVID-19 in metropolitan urban areas and for the containment of the circulation of SARS-CoV-2 in the migrant population in Italy', coordinated by the Italian Centre for Disease Control and Prevention (CCM) and funded by the Italian Ministry of Health, an experimental epidemiological, virological, and molecular SARS-CoV-2 surveillance system addressed to migrant populations in Sicily through Mediterranean routes was implemented. To this end, a multidisciplinary network supported by a hub&spoke system of laboratories was established in Sicily Region (Southern Italy), using molecular and Next Generation Sequencing (NGS) techniques to identify different SARS-CoV-2 strains in relation to migration flows. Herein, the lesson learnt through this integrated surveillance model, that was in place from February 2021 till the end of the COVID-19 emergency in Italy, are reported. Overall, the data emphasized the need for enhancing molecular surveillance in the areas of the globe where testing and sequencing resources are limited. The epidemiological, virological, and molecular SARS-CoV-2 monitoring, targeted to the migrant population, may also provide a valuable experimental model.

Distinct Communities of Bacteria and Unicellular Eukaryotes in the Different Water Masses of Cretan Passage Water Column (Eastern Mediterranean Sea).

Elucidating marine microbiota diversity and dynamics holds significant importance due to their role in maintaining vital ecosystem functions and services including climate regulation. This work aims to contribute in the understanding of microbial ecology and networking in one of the world's most understudied marine regions, the Eastern Mediterranean Sea. High-throughput 16S and 18S rRNA gene sequencing analysis was applied to study the diversity of bacteria and unicellular eukaryotes in the different water masses of the Cretan Passage during two seasonally-different sampling expeditions. We assumed that microbial associations differ between the surface and deepwater masses and created co-occurrence networks to evaluate this hypothesis. Our results unveiled vertical variations in both bacterial and unicellular eukaryotic diversity with species fluctuations indicative of seasonality being recorded in the surface water mass. Heterotrophic taxa and grazers related to organic matter degradation and nutrient cycling were enriched in the deepest water layers. Moreover, surface waters presented a higher number of microbial associations indicating abundant ecological niches compared to the deepest layer, possibly related to the lack of bottom-up resources in the oligotrophic deep ocean. Overall, our data provide insight in a heavily stressed, yet underexplored, marine area that requires further research to unravel the ecological roles of marine microbes. To our knowledge, this is the first study that combines molecular biology tools to provide data on both planktic prokaryotes and unicellular eukaryotes across the different water masses in this marine region of the Eastern Mediterranean basin.

Valorization of the Invasive Blue Crabs (Callinectes sapidus) in the Mediterranean: Nutritional Value, Bioactive Compounds and Sustainable By-Products Utilization.

The blue crab (Callinectes sapidus), originally from the western Atlantic Ocean, has recently spread to the Mediterranean and is now considered one of the one hundred most invasive species in that region. This opportunistic species, known for its adaptability to different temperatures and salinities, negatively impacts biodiversity and human activities such as fishing and tourism in the Mediterranean. However, the blue crab is gaining interest as a potential food resource due to its high nutritional value and delicate, sweet flavor. Its meat is rich in protein (14% to 30%), omega-3 fatty acids (EPA and DHA) and other essential nutrients beneficial for human health such as vitamins, and minerals. Utilizing this species in the production of new foods could help mitigate the negative impact of its invasiveness and offer economic opportunities. One challenge with this potential resource is the generation of waste. Approximately 6-8 million tonnes of crab shells are produced worldwide each year, leading to disposal problems and concerns regarding environmental sustainability. To improve economic and environmental sustainability, there is a need to valorize these residues, which are an important source of proteins, lipids, chitin, minerals, and pigments that can be processed into high-value-added products. However, especially in areas with industrial pollution, attention should be paid to the heavy metal (Cd and As) contents of blue crab shells. Studies suggest that blue crab by-products can be used in various sectors, reducing environmental impacts, promoting a circular economy, and creating new industrial opportunities.

The Fate of a Polygenic Phenotype Within the Genomic Landscapes of Introgression in the European Seabass Hybrid Zone.

Unraveling the evolutionary mechanisms and consequences of hybridization is a major concern in biology. Many studies have documented the interplay between recombination and selection in modulating the genomic landscape of introgression, but few have considered how associations with phenotype may affect this landscape. Here, we use the European seabass (Dicentrarchus labrax), a key species in marine aquaculture that undergoes natural hybridization, to determine how selection on phenotype modulates the introgression landscape between Atlantic and Mediterranean lineages. We use a high-density single nucleotide polymorphism array to assess individual local ancestry along the genome and improve the mapping of muscle fat content, a polygenic trait that is divergent between lineages. Taking into account variation in recombination rates, we reveal a purging of Atlantic ancestry in the admixed Mediterranean populations. While Atlantic individuals had higher muscle fat content, we observed that genomic regions associated with this trait in Mediterranean populations displayed reduced introgression of Atlantic ancestry. These results emphasize how selection against maladapted alleles shapes the genomic landscape of introgression.

Active mussel biomonitoring for the health status assessment of the Western Mediterranean Sea.

The Western Mediterranean coast is under the influence of anthropogenic pressures, including land use, increasing amounts of dangerous waste and habitat destruction. In 2021, the French RINBIO network (http://www.ifremer.fr/envlit/) originally dedicated to assess chemical contamination in the region, focused on biological effects produced by contaminants and the interaction with natural variability in mussels using an active caging strategy. Cell and tissue level biomarkers were applied for 17 sampling sites divided in three sub-regions categorized by different environmental conditions. Results provide critical information for ecosystem health assessment using mussels as sentinel species in the Western Mediterranean Sea. The influence of natural and confounding factors (trophic condition, reproductive cycle, caging strategy), on biological responses to mild chemical contamination, was discussed and discriminated for health status assessment. Results provide valuable data available as reference values for the assessment of biomarkers and histopathological alterations for large-scale active biomonitoring campaigns in the Western Mediterranean Sea.

Serum chemistry, thyroxine concentration, and blood cell morphology of wild, young Blackchin Guitarfish Glaucostegus cemiculus sampled on the eastern Mediterranean coastline.

OBJECTIVE: The Blackchin Guitarfish Glaucostegus cemiculus is endemic to the Mediterranean Sea and is critically endangered, but relevant routine laboratory data are unavailable. Our objectives were to determine the packed cell volume (PCV), comprehensive serum chemistry analytes, and serum total thyroxine (sTT4) concentration; compare serum albumin and serum globulin concentrations as measured by two different methods; and describe the blood cell morphology of healthy, free-ranging Blackchin Guitarfish. METHODS: Wild Blackchin Guitarfish were captured using a seine net. Blood samples for serum chemistry and hematological analyses were obtained and measured using routine laboratory methods. The fish were tagged and released. RESULT: This study included 43 Blackchin Guitarfish (17 males and 26 females) that were younger than 6 months as estimated based on total length and body weight. The median PCV (n = 23) was 22% (minimum-maximum [min-max] = 15-25%). Median sTT4 (n = 10) measured by chemiluminescence immunoassay was 7.86 nmol/L (min-max = 7.52-9.57 nmol/L). The study included a comprehensive, 25-analyte serum chemistry analysis (e.g., serum iron and unbound and total iron-binding capacity) and a morphological description of all blood cells. Serum electrophoresis (SEP; n = 13) yielded a consistent serum albumin-migrating protein fraction and four globulin fractions. Serum electrophoretograms corroborating these results are presented. CONCLUSION: In Blackchin Guitarfish, the serum albumin-migrating fraction measured by SEP combined with serum total protein concentration yields a much higher albumin concentration compared to that measured by bromocresol green spectrophotometry. The true identity of this albumin-migrating fraction remains to be identified. The analytes' calculated 2.5-97.5% interpercentile intervals should be considered as reference intervals applying to Blackchin Guitarfish of similar age but should be applied cautiously to adult fish.

Biological activities of derived pigments and polyphenols from the newly recorded alga Phyllymenia gibbesii.

The newly recorded Phyllymenia gibesii in the Mediterranean Sea at Alexandria coast of Egypt is regarded as a significant source of bioactive substances and is applied as an antioxidant, anti-inflammatory, and antimicrobial agent. According to the HPLC chromatograms, the acetone extract of P. gibesii comprised ten photosynthetic pigments (chlorophyll-a, chlorophyll-d, α-carotene, ß-carotene, phycocyanin, allophycocyanin, antheraxanthin, ß-cryptoxanthin, lutein, and violaxanthin). Total carotenoids were the dominant class in the pigments' profile, achieving a concentration of 257 g/g dry weight. The P. gibbesii extract had a total content of phenols (146.67 mg/g) and a total content of flavonoids (104.40 mg/g). The capacity of all the investigated biological activities augmented with the concentration of the algal extract. The maximal DPPH scavenging capacity was 81.44%, with an inhibitory concentration (IC50) of 9.88 µg/mL. Additionally, the highest ABTS scavenging capacity was 89.62%, recording an IC50 of 21.77 µg/mL. The hemolytic activity of P. gibbesii attained a maximum capacity of 49.88% with an IC50 of 100.25 µg/mL. Data also showed the maximum anti-inflammatory effectiveness at 81.25%, with an IC50 of 99.75 µg/mL. Furthermore, the extract exhibited antimicrobial capacity against all reference strains, particularly at high concentrations (0.1 mg/mL), with the greatest effect on C. albicans and E. coli.

Marine fungal community composition and diversity across a polluted site in the south Mediterranean coast: the Monastir Bay, Tunisia.

Marine fungi communities play a crucial role in the recycling of nutrients, restoration of biological systems, and the overall functioning of ecosystems. While aquatic fungal communities do react to pollution, there is a significant lack of information regarding the changes in the fungal community's structure, caused by marine pollution. In this study, we aim to address this gap in knowledge by investigating the range and makeup of fungal species present in marine environments in a polluted bay in Tunisia, spanning a biodiversity hotspot (Monastir Bay). Sequence analysis of the internal transcribed spacer region from culturable mycobiome and physicochemical parameters were investigated at seven sites in the bay. A total of 32 fungal taxa were identified at the genus and/or species levels and were assigned to four major groups (Aspergillacae 37.5%, Dothiomyceta 21.87%, Sordariamyceta 28.12%, and Yeasts 12.5%) with a remarkable predominance of Aspergillus genus. Assessment of the Shannon-Wiener diversity index and the Simpson dominance index revealed that the highest species diversity index (0.84) was recorded at the Kheniss site. Our results suggest the existence of diverse fungal communities, can be considered a useful community model for further ecological and evolutionary study of fungi in the bay.

Soundscape analysis can be an effective tool in assessing seagrass restoration early success.

Restoration of vulnerable marine habitats is becoming increasingly popular to cope with widespread habitat loss and the resulting decline in biodiversity and ecosystem services. Lately, restoration strategies have been employed to enhance the recovery of degraded meadows of the Mediterranean endemic seagrass Posidonia oceanica. Typically, habitat restoration success is evaluated by the persistence of foundation species after transplantation (e.g., plant survival and growth) on the short and long-term, although successful plant responses do not necessarily reflect the recovery of ecosystem biodiversity and functions. Recently, soundscape (the spatial, temporal and frequency attribute of ambient sound and types of sound sources characterizing it) has been related to different habitat conditions and community structures. Thus, a successful restoration action should lead to acoustic restoration and soundscape ecology could represent an important component of restoration monitoring, leading to assess successful habitat and community restoration. Here, we evaluated acoustic community and metrics in a P. oceanica restored meadow and tested whether the plant transplant effectiveness after one year was accompanied by a restored soundscape. With this goal, acoustic recordings from degraded, transplanted and reference meadows were collected in Sardinia (Italy) using passive acoustic monitoring devices. Soundscape at each meadow type was examined using both spectral analysis and classification of fish calls based on a catalogue of fish sounds from the Mediterranean Sea. Seven different fish sounds were recorded: most of them were present in the reference and transplanted meadows and were associated to Sciaena umbra and Scorpaena spp. Sound Pressure Level (SPL, in dB re: 1 µPa-rms) and Acoustic Complexity Index (ACI) were influenced by the meadow type. Particularly higher values were associated to the transplanted meadow. SPL and ACI calculated in the 200-2000 Hz frequency band were also related to high abundance of fish sounds (chorus). These results showed that meadow restoration may lead to the recovery of soundscape and the associated community, suggesting that short term acoustic monitoring can provide complementary information to evaluate seagrass restoration success.

Genetic drift, historic migration, and limited gene flow contributing to the subpopulation divergence in wild sea beet (Beta vulgaris ssp. maritima (L.) Arcang).

Cultivated beet (Beta vulgaris L. ssp. vulgaris) originated from sea beet (B. vulgaris ssp. maritima (L.) Arcang), a wild beet species widely distributed along the coasts of the Mediterranean Sea and Atlantic Ocean, as well as northern Africa. Understanding the evolution of sea beet will facilitate its efficient use in sugarbeet improvement. We used SNPs (single nucleotide polymorphisms) covering the whole genome to analyze 599 sea beet accessions collected from the north Atlantic Ocean and Mediterranean Sea coasts. All B. maritima accessions can be grouped into eight clusters with each corresponding to a specific geographic region. Clusters 2, 3 and 4 with accessions mainly collected from Mediterranean coasts are genetically close to each other as well as to Cluster 6 that contained mainly cultivated beet. Other clusters were relatively distinct from cultivated beets with Clusters 1 and 5 containing accessions from north Atlantic Ocean coasts, Clusters 7 and Cluster 8 mainly have accessions from northern Egypt and southern Europe, and northwest Morocco, respectively. Distribution of B. maritima subpopulations aligns well with the direction of marine currents that was considered a main dynamic force in spreading B. maritima during evolution. Estimation of genetic diversity indices supported the formation of B. maritima subpopulations due to local genetic drift, historic migration, and limited gene flow. Our results indicated that B. maritima originated from southern Europe and then spread to other regions through marine currents to form subpopulations. This research provides vital information for conserving, collecting, and utilizing wild sea beet to sustain sugarbeet improvement.

Age and environment are the main drivers shaping the wild common sole (Solea solea) microbiota.

Microbiota plays an essential role in fish growth and health and may be influenced by the changing environmental conditions. Here, we explored the microbiota of wild common sole, one of the most important fishery resources in the Mediterranean Sea, collected from different areas in the North Adriatic Sea. Our results show that the sole microbiota differs from that of the surrounding environment and among the different body sites (gill, skin and gut). Gut microbiota composition showed to be strongly related to fish age, rather than maturity, sex or sampling site. Age-related shifts in gut microbial communities were identified, with increased abundances of Bacteroidia and Desulfobacteria, unveiling potential microbial proxies for age estimation crucial for fisheries management. Our results expand the limited knowledge of the wild common sole microbiota, also in the light of the potential usefulness of the fish microbiota as a tool for future stock identification and connectivity studies.

From ctenophores to scyphozoans: parasitic spillover of a burrowing sea anemone.

Most host-parasite associations are explained by phylogenetically conservative capabilities for host utilization, and therefore parasite switches between distantly related hosts are rare. Here we report the first evidence of a parasitic spillover of the burrowing sea anemone Edwardsiella carnea from the invasive ctenophore Mnemiopsis leidyi to two scyphozoan hosts: the native Mediterranean barrel jellyfish Rhizostoma pulmo and the invasive Indo-Pacific nomad jellyfish Rhopilema nomadica, collected from the Eastern Mediterranean Sea. Edwardsiella carnea planulae found in these jellyfish were identified using molecular analyses of the mitochondrial 16S and nuclear 18S rRNA genes. Overall, 93 planulae were found on tentacles, oral arms, and inside of the gastrovascular canals of the scyphomedusae, whereas no infection was observed in co-occurring ctenophores. DNA metabarcoding approach indicated seasonal presence of Edwardsiella sp. in the Eastern Mediterranean mesozooplankton, coinciding with jellyfish blooms in the region. Our findings suggest a non-specific parasitic relationship between Edwardsiella carnea and various gelatinous hosts based on shared functionality rather than evolutionary history, potentially driven by shifts in host availability due to jellyfish blooms. This spillover raises questions about the ecological impacts of parasitism on native and invasive scyphozoan hosts and the potential role of Edwardsiella in controlling their populations.

Functional ecological traits in young and adult thalli of canopy-forming brown macroalga Gongolaria barbata (Phaeophyta) from a transitional water system.

Background: Gongolaria barbata is a canopy-forming brown macroalga that thrives in the intertidal and subtidal habitats of the warm-temperate Mediterranean Sea, which is particularly exposed to environmental changes due to its peculiar geographical location and exposure to both global and local stressors. Testing whether this species is featured by specific functional, eco-physiological and biochemical traits allowing an efficient use of habitat resources and adaptation to environmental stress, and whether this potential might change with population growth, is essential for predicting the performance of the algae under different environmental abiotic variables (e.g., temperature, nutrient availability, light) and biotic interactions (such as grazing). Methods: Young (juveniles) and adult thalli of G. barbata were sampled in the winter season from the Venice Lagoon, Italy, featured by high environmental changes (temperature, salinity) and analyzed for thallus dry matter content (TDMC), photosynthetic activity, photosynthetic pigment and protein content, and antioxidant capacity to assess if thallus age may be considered a significant driver in determining the ecological responses of this species to environmental changes. Results: Our results showed that TDMC was higher in adults than juveniles. At the functional level, rapid light curves indicated an elevated photosynthetic efficiency in juveniles compared to adults highlighted by the higher quantum yield of PSII electron transport, electron transport rate, and Rubisco content observed in juveniles. On the contrary, adults exhibited a higher non-photochemical quenching and total pigment concentration. No difference in maximum PSII photochemical efficiency and D1 protein content between the two thalli groups was found. Along with better photosynthesis, juveniles also displayed a higher amount of total polyphenols, flavonoids, and tannins, and a stronger antioxidant capacity compared to adults. Conclusions: Our findings revealed significant differences in the eco-physiological characteristics of G. barbata at different growth stages. It was observed that young thalli, allocate more energy to photosynthesis and chemical defenses by increasing the production of antioxidant compounds, such as polyphenols, flavonoids, and tannins. With growth, thalli likely adopt a more conservative strategy, reducing photosynthesis and promoting structural biomass accumulation to mitigate the potential risks associated with prolonged exposure to environmental stressors, such as the wavy way. Although our study focused on a single phase of G. barbata life cycle under winter settings, it offers preliminary insights into this species eco-physiological traits and auto-ecology. Future research could explore the potential implications of these findings, evaluating the species' resilience to environmental changes at the population level.

Heavy metal levels of outdoor dust from the Eastern Mediterranean Sea region and assessment of the ecological and health risk.

As a result of some chemical element (heavy metals) pollution of dust, environmental pollution of dust has become an increasing concern, necessitating an assessment of risks to both ecology and human health, particularly in urban areas. Most of these pollutants settle on the outdoors and eventually become part of the outdoor dust. These will have negative long-term repercussions on ecosystems and human health. In this research, energy dispersive X-ray fluorescence (EDXRF) spectrometry analytical method was used to assess the pollution characteristics of the eight heavy metals (HMs): Mn, Cu, As, Hg, Ni, Cr, Zn, and Pb in the East Mediterranean Sea area. The concentration of As, Mn, Cr, Cu, Hg, Ni, Pb, and Zn analyzed in outdoor dust samples varied from 0.94 to 19.52 mg kg-1, 190.08 to 1019.7 mg kg-1, 20.46 to 45.9 mg kg-1, 19.5 to 62.56 mg kg-1, 0.01 to 0.93 mg kg-1, 10.48 to 40.64 mg kg-1, 12. 6 to 36.1 mg kg-1, and 48.96 to 112.41mg kg-1, respectively. HMs have been detected in the outdoor dust samples analyzed in the study, and, as a result, mean concentrations followed the order Mn > Zn > Cu > Cr > Ni > Pb > As > Hg, respectively. The ecological risk was observed at various contamination levels, with As and Hg pollution being the most severe. The highest hazard quotient (HQ) for adults and children was determined as a result of As and Cr, respectively. According to the US-EPA health risk threshold, the cancer risk in the study area is negligible.