Search Results (84)

Coastal lagoons are key wintering habitats for waders, yet long-term changes in their community structure remain poorly understood in Mediterranean systems. We analyzed a 30-year dataset (1993–2022, excluding 2021) of wintering waders in the Venice Lagoon to assess trends in abundance, community structure, thermal composition and spatial patterns. Total abundance increased significantly (+3.5% yr⁻¹), while species richness ranged between 12 and 21 species per winter and increased over time. Community structure changed markedly, but the assemblage remained highly dominated by Dunlin Calidris alpina without evidence of increasing dominance or declining evenness. Instead, richness, Shannon diversity and Pielou’s evenness increased, whereas Berger–Parker dominance declined slightly but significantly. Species-level analyses showed a prevalence of increasing trends: ten of the 19 species analyzed increased significantly, three declined, one was stable, and five showed uncertain trends. Multivariate analyses based on Bray–Curtis dissimilarities showed significant compositional differences among approximately decadal periods, both including and excluding Dunlin, indicating that long-term assemblage reorganization was not solely attributable to the dominant species. The Community Temperature Index (CTI) increased significantly (p = 0.001), but this abundance-weighted signal was weak in biological magnitude and contrasted with a declining presence–absence CTI; moreover, this pattern was not robust to the exclusion of Dunlin, indicating dominance-driven dynamics. Spatial analyses revealed a strong increase in the proportion of counted birds recorded in the open lagoon (p < 0.001) and a decline in fish farms (p < 0.001), but this pattern disappeared after excluding Dunlin, suggesting that the apparent spatial redistribution was largely driven by this species. Overall, the assemblage is increasing and compositionally reorganized, while remaining strongly influenced by Dunlin dominance, highlighting the need to integrate species- and community-level approaches when interpreting ecological indicators. Full article

Introduction: The Atlantic bluefin tuna Thunnus thynnus (ABFT) is a large pelagic apex predator with adaptations for a life of ceaseless swimming during long-distance oceanic migrations. The environmental physiology and energetics of tunas have interested researchers for many decades, but they are notoriously challenging to study because they are so difficult to keep in captivity. Adult ABFT are, however, now fattened in cages at various sites in the Mediterranean, while juveniles are reared from hatching every year at the Unique Scientific and Technological Infrastructure for ABFT aquaculture (ICAR-IEO), near Cartagena in Spain. These facilities provide access to animals, but the fish remain very problematic to study because of their highly active but physiologically delicate nature and, for adults, their very large sizes. Objective: To study the in vivo physiology and behaviour of ABFT. Methodology: We used heart rate biologging and high residency acoustic tracking to follow cardiac and swimming activity over a year in n = 24 adult ABFT (mass range 25 to 200 kg) held in a cage off the coast of Malta (Malta Fish Farming). We then performed swim tunnel respirometry on young of the year juveniles (500g) at ICRA-IEO, but subsequently took a ‘hands-off’ approach, using video analyses and group respirometry on free-swimming animals. Results: The descriptive approach on the caged adults provided understanding of how seasonal water temperatures (15 to 28 °C) affect tuna physiology and behaviour. The swimming respirometry on juveniles revealed that their performance was constrained by confinement in the tunnel, compared to when they were swimming at their spontaneous preferred speed in their rearing tank. Video analyses provided insights into the effects of size (25 to 200 cm bodylength) on spontaneous swimming speeds and coupled with tank respirometry, revealed how progressive hypoxia affects the metabolic rate and schooling behaviour of juveniles. Conclusions: These opportunistic and disparate pieces of information are nonetheless valuable for such a fascinating but data-deficient species, and can be useful in mechanistic models for management of an extremely valuable fishery in a context of global change. Full article

Using International Waterbird Census data spanning 1993–2022, we analysed temporal trends in the abundance and community composition of wintering waterbirds in the Venice Lagoon (NE Italy). We examined total numbers, major lagoon macro-areas (fish farms, open lagoon, coastal littoral zone, minor wetlands), species-level and guild-level trends and assessed climate-related community changes through the Community Temperature Index (CTI). Total wintering waterbird abundance increased markedly over the study period, from 74,348 birds in 1993 to 445,350 in 2022. Fish farms (about 20% of the total area) hosted the largest number of individuals (about 83%) and accounted for most of the lagoon-wide increase, while open lagoon (15%) and coastal littoral (<2%) areas showed weaker and more variable dynamics. Species-level analyses revealed pronounced heterogeneity, with strong increases in several Anatidae, contrasted by stable or declining trends in other species. The CTI exhibited a significant long-term increase, indicating a progressive shift towards communities dominated by warm-affinity species. CTI decomposition nevertheless showed this signal was disproportionately driven by a limited number of highly abundant species. Our results indicate that wintering waterbird dynamics in the Venice Lagoon are shaped by the interaction between large-scale climatic processes and local habitat management, particularly within fish farms. While management practices can likely sustain exceptionally high wintering numbers and potentially buffer climate-driven redistribution, they may also promote strong species dominance and associated ecological risks. Integrating long-term census data with climate and functional indicators provides a robust framework for understanding and managing Mediterranean wetlands under ongoing climate change. Full article

Fish is highly prone to spoilage due to a combination of intrinsic biochemical processes and microbial proliferation, which together drive rapid quality deterioration during post-harvest handling and storage. These processes are further accelerated by factors such as elevated temperatures, mechanical damage, and suboptimal handling. In Mediterranean aquaculture, ice slurry is the standard harvesting method. This study aimed to characterize the initial post-harvest enzymatic activity of key proteolytic enzymes, calpain, collagenase, cathepsin B (CTSB), and cathepsin L (CTSL), in the white muscle of three commercially important species (Sparus aurata, Dicentrarchus labrax, and Pagrus major) harvested under standard practices across three seawater harvest temperatures (low, medium, and high). Muscle samples were collected over a 13-day chilled storage period post-harvest, and enzymatic activity was assessed using standardized fluorometric assays. Our findings establish the basal post-mortem proteolytic profiles for each species and reveal marked species-specific differences in enzyme activity patterns. Calpain and collagenase exhibited early and parallel activation, while CTSB and CTSL showed a coordinated increase during storage. Harvest temperature emerged as a critical factor, with the highest enzymatic activities consistently observed during the moderate temperature period. These results underscore the importance of species-specific physiology and seasonal conditions in shaping post-harvest filet degradation, offering a basis for refining harvest strategies to enhance quality management in Mediterranean aquaculture. Full article

The recent growth of Blue Economy-related human activities has increased underwater noise pollution. Sound is a key factor in ensuring the well-being of marine animals as it allows them to communicate with each other and extract valuable information from the environment. Although the Marine Strategy Framework Directive requires monitoring programs to achieve good environmental status, there remains a significant deficit of information concerning three key domains: the characteristics of the underwater soundscape, its transformation due to anthropogenic activities, and the effects of noise on marine animals. This study aimed to evaluate the impact of anthropogenic activities on marine acoustic environments. Acoustic metrics and ecoacoustic indices were applied to characterise variability and assess daily, weekly, and seasonal patterns, as well as the effects of trawling restrictions. Three underwater soundscapes were compared in this study: two natural environments in the Mediterranean Sea and one artificial environment, a land-based fish farm tank. High anthropogenic noise levels were found, primarily due to fishing vessels near the selected locations. Similarly, the soundscape exhibited notable seasonal variations (annual and weekly), demonstrating a significant dependence on tourist activities. The results highlight the benefits of acoustic parameters as a tool for monitoring environmental conditions over time. Full article

Betanodavirus infection poses a significant threat to marine fish species in the Mediterranean, affecting both aquaculture and wild populations. Despite increasing evidence of viral circulation in farmed and wild fish, data on natural outbreaks in wild groupers remain limited. This study investigated mortality episodes in wild dusky groupers (Epinephelus marginatus) within two marine protected areas (MPAs): Portofino MPA (Liguria, Italy) and Larvotto MPA (Principality of Monaco) during 2018–2019. Pathological examinations and virological diagnostics confirmed that the causative agents were betanodavirus strains belonging to the RGNNV genotype. Phylogenetic analyses revealed high genetic similarity among viral strains detected at geographically distant sites and across host species, suggesting potential regional connectivity mediated by mobile vectors or environmental transport. Seawater temperature analysis indicated that extreme and prolonged high-water temperatures were prodromal and coincided with observed outbreaks, supporting a role for thermal stress in triggering outbreak onsets. These findings highlight the susceptibility of wild dusky grouper populations to betanodavirus and underscore the interplay between host behavior, environmental conditions, and pathogen dynamics. The study emphasizes the importance of integrated health surveillance strategies within and around MPAs to monitor fish health and environmental parameters, thereby conserving wild fish populations and biodiversity. Full article

Piscine lactococcosis is an emerging bacterial disease that threatens freshwater and marine aquaculture in the Mediterranean region. This study characterized isolates of Lactococcus garvieae and Lactococcus petauri from farmed fish through molecular identification, genomic typing and antimicrobial susceptibility testing. A total of 39 bacterial strains were analyzed using species-specific real-time PCR assays, multilocus sequence typing and broth microdilution to determine minimum inhibitory concentrations. Results suggest a temporal shift in freshwater systems, where L. garvieae predominated in earlier isolates (mainly ST13, CC4), while L. petauri (ST14, CC14) appears as the dominant species in recent years. In marine fish, only L. garvieae was detected, mainly ST95 (CC95), a lineage previously reported in Europe. Molecular variability was found in both species with lineages capable of infecting livestock and humans. Amoxicillin displayed promising results; florfenicol showed moderate activity, while flumequine exhibited no inhibitory effect. Oxytetracycline and trimethoprim–sulfamethoxazole showed variable results requiring prudent use. These region-specific susceptibility profiles provide updated baseline data to guide empirical antimicrobial therapy while awaiting laboratory confirmation, highlighting the evolution of lactococcosis in aquaculture and emphasizing the need for molecular surveillance, antimicrobial stewardship, and vaccine updates within a One Health framework to mitigate impacts on Mediterranean aquaculture and public health. Full article

From 2011 to 2021, marine and brackish water aquaculture production in the Mediterranean and Black Seas increased by 91.3% in volume and 74.5% in value, primarily due to the rise in finfish marine aquaculture. In the Aegean Sea, a significant aquaculture hotspot, Greece and Turkey lead in fish farm numbers and production volume. This study uses Google Earth satellite imagery to map and analyze fish farming cages along the Aegean Sea, comparing findings with the EMODnet dataset. By cataloging fish farm cages along the Greek and Turkish coastlines, we identified 4729 cages in Greece and 2349 in Turkey, with Turkey’s cages occupying a larger area (1.64 km²) than Greece (1.35 km²) due to their larger average size. The analysis revealed significant discrepancies between satellite-derived data and EMODnet records, particularly along the Greek coastline, highlighting gaps in existing datasets. Our findings underscore the need for improved marine spatial planning and management as well as for consistent data collection to support sustainable aquaculture. Full article

Over the past decade, increasing attention has been given to the impacts of anthropogenic microparticle (AM) pollution on marine ecosystems. This study investigates AM ingestion in three commercially important fish species—Sparus aurata Linnaeus, 1758, Dicentrarchus labrax Linnaeus, 1758, and Boops boops Linnaeus, 1758—collected from both wild and farmed populations in Greek marine and lagoon environments. A total of 60 specimens were sampled from the Messolonghi Lagoon, Rhodes Island, and the Cyclades. AM were detected in 61.7% of the individuals analyzed. The mean number of ingested items per individual was 1.1 ± 1.2 in B. boops, 1.0 ± 1.7 in wild and 2.3 ± 2.1 in farmed S. aurata, and 2.5 ± 3.1 in wild and 3.6 ± 2.2 in farmed D. labrax. Ingestion ranged from 0 to 9 items per fish. No significant correlations were found between fish size and either the number or the size of ingested AM in any species. The ingested AM were primarily classified as fibers and fragments, displaying variability in size and color. Black was the dominant color across all species, followed by red and blue, while yellow was rarely observed. A statistically significant difference in the mean size of AM was recorded between wild and farmed D. labrax, whereas no such difference was observed for S. aurata. Overall, these findings provide new evidence on AM contamination in seafood species and highlight their occurrence in both natural and aquaculture environments of the eastern Mediterranean. Full article

In Italy, karyotype analysis is routinely performed on all young males intended for reproduction to screen for chromosome abnormalities. This practice gained prominence following the identification of a complex chromosome abnormality in a well-known bull named Magnifico and its progeny. This procedure significantly enhances the value of the Mediterranean Italian River Buffalo breed, particularly in the context of artificial insemination both within Italy and in other countries importing semen. In the current study, 159 young Mediterranean Italian River Buffalo (MIRB) males intended for reproduction, 30 females with fertility issues, 3 young females and a male co-twin were investigated by analyzing their karyotype using both CBA- and RBA-banding. All males displayed a normal karyotype (2n = 50, XY), although one animal displayed an abnormal X-chromosome with C-band polymorphism, as it is C-band negative when this chromosome normally shows the largest C-band among all chromosomes. This result was also confirmed by the FISH-mapping technique using three bovine BAC-clones containing SAT-I, SAT-III and SAT-IV. Cytogenetic investigation showed that seven females, along with one male co-twin, were affected by freemartinism (XX/XY leukocyte chimerism) and were subsequently removed from the farm. In two of these females, clinical and necroscopic examinations showed severe damage of the internal reproductive organs. Full article

The European seabass is a key Mediterranean aquaculture species, vital for sustainably meeting rising global protein demands amid declining wild fish stocks. Genetic analyses have identified the six6 gene as a candidate target of domestication and selective breeding, with two SNPs showing significant genotypic differences between wild and farmed European seabass populations. Further analyses revealed differential six6 expression between larval and juvenile stages, suggesting a potential developmental role. This study explores associations between these SNPs and important aquaculture traits across early developmental stages. Seabass samples were examined at 34 days post-hatching (dph, larval stage) and 71 dph (juvenile stage). We examined associations between specific six6 SNPs and morphological traits using traditional morphometrics, analyzing 20 and 26 characteristics in the larval and juvenile stages, respectively. Shape and size differences were examined with allometric correction. The six6 gene was primarily associated with body length, height, and caudal fin morphology. Notably, homozygous six6 genotype combinations at the studied SNPs were associated with increased body length in a developmental stage-specific manner. Variation in this gene also appeared to influence eye development in juveniles. These findings offer phenotypic evidence supporting previous genetic and expression studies in European seabass, highlighting their potential applications in fisheries and aquaculture. Full article

The interactions between marine predators such as the Mediterranean monk seal (Monachus monachus) and fish farms have raised concerns regarding the potential environmental impacts of the industry on surrounding marine ecosystems. This study investigated the potential role of fish farm workers in monitoring marine biodiversity around aquaculture sites, comparing their potential involvement with that of other maritime workers. Interviews were conducted with maritime workers, including fish farm workers, in order to understand their perceptions of monk seal interactions with fish farms. The author also carried out direct data collection at fish farms to validate these perceptions. The results show a strong alignment between the workers’ perceptions and the data collected by the author on key parameters such as the presence, frequency, and seasonality of monk seals on fish farms. Furthermore, 75% of the 16 fish farm workers interviewed expressed no animosity toward monk seals. This underscores fish farm workers potential for involvement in monitoring initiatives and their understanding of monk seal interactions on fish farms. Given their constant presence at sea and proximity to key interaction zones, maritime workers are well-positioned to monitor environmental pressures and provide valuable data. With appropriate training, these workers could become valuable participants in targeted citizen science efforts, enhancing the public image of the aquaculture industry and advancing research on marine life in the vicinity of aquaculture installations. Full article

Hybrid striped bass (HSB), a cross between white bass (Morone chrysops) and striped bass (Morone saxatilis), has garnered attention in aquaculture due to its adaptability, rapid growth, and high market value. This study investigates the morphometric, nutritional, and blood characteristics of HSB reared in a recirculating aquaculture system (RAS) in Sicily, Italy, over a 22-month grow-out period. The fish were managed under standardized feeding and water quality protocols, with weekly monitoring of the physicochemical parameters. A total of 21 clinically healthy fish, averaging 571.33 ± 129.32 in body weight, were randomly sampled in the spring season from a commercial RAS facility equipped with biological filtration, UV sterilization, and seasonally regulated water parameters. The results revealed strong positive correlations between the morphometric parameters and blood indices, such as red blood cell (RBC) count, hemoglobin (Hb) levels, and hematocrit (Hct), highlighting their importance as health indicators. The proximate composition revealed an average moisture content of 75.55 ± 1.49, crude protein at 20.29 ± 0.26, total lipid at 4.25 ± 0.97, and ash content at 1.69 ± 0.17. Additionally, statistical analyses, including a principal component analysis (PCA), identified relationships between body size, nutritional content, and blood parameters, emphasizing the role of body size in influencing nutritional and health outcomes. The findings of this study are crucial for optimizing farming protocols and improving the health and productivity of HSB in RAS under Mediterranean conditions. Full article

This review examines the current state of the supply chain management for Dicentrarchus labrax (sea bass) and Sparus aurata (sea bream), two key commercial fish species in the Mediterranean. It provides a comprehensive analysis of sustainable innovations in aquaculture, processing, and packaging, with particular attention to circular economy-based biopreservation techniques. A major focus is on the Integrated Multi-Trophic Aquaculture (IMTA) system, an advanced farming approach that enhances sustainability, promotes circular resource utilization, and improves fish welfare. By fostering ecological balance through the co-cultivation of multiple species, IMTA contributes to the overall quality of fish products for human consumption. Beyond aquaculture, the review addresses the critical challenge of food loss, which stems from the high perishability of fish during storage and processing. In this regard, it highlights recent advancements in biopreservation strategies, including the application of antagonistic microorganisms, their metabolites, and plant-derived extracts. Particular attention is given to the development of edible antimicrobial films, with a focus on the valorization of citrus processing by-products for their production. By centering on innovations specific to the Mediterranean context, this review underscores that a holistic, integrative approach to supply chain management is essential for transitioning the aquaculture sector toward greater efficiency and sustainability. Full article

This study aims to explore aquaculture professionals’ perspectives on, attitudes towards and understanding of Mediterranean farm fish health management, regarding Artificial Intelligence (A.I.), and to shed light on the factors that affect its adoption. A survey was distributed during a major fish health management conference, representing more than 70% of Greek domestic production. A total of 73 questionnaires were collected, for which descriptive statistics and statistical analysis followed. Gender and age were shown to affect interest in A.I. and in viewing A.I. as a partner rather than a competitor. Age was additionally shown to affect trust in A.I. estimates and anticipation that A.I. will contribute to professional development. Education level shows no significant effect. Knowledge of A.I. is positively correlated with A.I. usage (r = 0.43, p < 0.05), as is interest in learning about A.I. (r = 0.64). A.I. usage is in turn positively correlated with eagerness to see its contribution (r = 0.72). Despite the fact that 64.4% characterized their knowledge as little or non-existent, 67.1% expressed interest in learning more, while 43.8% believe that A.I. will revolutionize aquaculture and 74% do not fear they will be replaced by A.I. in the future. The findings highlight the importance of targeted educational initiatives to bridge the knowledge gap and encourage trust in A.I. technologies. Full article