Search Results (116)

Parasitic diseases can be a significant constraint on aquaculture industries, which continue to develop in response to the rise in global demand for sustainable protein sources. Blood flukes, Cardicola forsteri and Cardicola orientalis, are economically significant parasites of Southern bluefin tuna (Australia), Pacific bluefin tuna (Japan), and Atlantic bluefin tuna (Mediterranean) as they are responsible for blood vessel obstruction in the gills leading to branchitis and mortalities when untreated. Here, we have defined the mitochondrial genomes for these species—the first for any aporocotylids. Oxford nanopore long-read sequencing was used to sequence C. orientalis from a single individual. The mitochondrial genome of C. forsteri was assembled and curated from available sequence data. Both Cardicola spp. mitogenomes contained 12 protein coding, 2 ribosomal and 22 tRNA genes, with the gene order matching that of Asian schistosomes. A control region was identified for each species which contained long and short repeats; the region for C. forsteri was longest, and the overall pattern differed between the two species. A surprisingly high nucleotide diversity was observed between the two species, generating interest into the mitochondrial genes of related species. This paper provides a useful resource for future genetics-based research of aporocotylids and other flatworm parasites of socioeconomic significance. Full article

Background/Objectives: Calcitriol, the active form of vitamin D, has a broad physiological effect, and its deficiency has been identified as a risk factor for many diseases. This study aimed to analyze the dietary intake of vitamin D and the factors determining its intake among Polish post-primary school students. The data obtained were then related to the dietary recommendations for the Polish population. Methods: The study was conducted on a nationwide sample of 3257 male adolescents (aged 14–20 years) recruited from all macroregions of Poland. Dietary vitamin D intake (dVDi) was assessed using the Vitamin D Estimation Only–Food Frequency Questionnaire (VIDEO-FFQ). Results: The median dietary intake of vitamin D was 4.36 µg daily. This value was below the recommended intake of 15 µg of vitamin D, according to Polish standards, in almost 80% of the study group. The observed dietary vitamin D intake bellow the recommended level ranged from 35.5% of students attending schools in the North-Western macroregion to 93.7% in the Central macroregion, from 45.4% of students attending schools located in the countryside to 92.7% in big cities, from 85.3% among underweight students to 76.7% of obese students, over 77% in both age groups (14–17 and 18–20 years old), and over 78% in both groups: supplementing and not supplementing vitamin D. Fish and fish products provided the highest vitamin D (38.7%), while cereal products and fats provided the lowest (4.49% and 4.35%, respectively). The highest amounts of vitamin D were provided by salmon, rainbow trout, herring, and eel (fish species containing 7–15 µg of vitamin D in 100 g of product), and halibut, mackerel, brook trout, sole, and tuna (fish species containing 1.05–4 µg of vitamin D in 100 g of product), and these fish were consumed in the largest quantities by male adolescents. Dietary vitamin D intake was notably higher in adolescents from the North-Western macroregion of Poland (median: 50.57 vs. 3.72–5.18 µg daily for other macroregions), those attending schools in the countryside (median: 49.49 vs. 3.97–4.39 µg daily for other locations of the school), those with a normal body weight (median: 4.59 vs. 3.38 µg daily for adolescents with underweight), and those who took vitamin D supplements (median: 4.71 vs. 4.06 µg daily for adolescents not supplemented with vitamin D). However, the results showed that dVDi was not dependent on age. Conclusions: The study results indicate that low dVDi among Polish male adolescents can be attributed to the limited supply of vitamin D from dietary sources, especially fish and fish products. The necessity for interventions has been identified, including nutritional education on the role of vitamin D and its sources in the diet. Full article

Canning is an excellent solution to provide convenient, affordable, nutritious, and safe seafood with a long shelf life. However, many canned products use tuna, sardines, and Atlantic chub mackerel, species that raise sustainability concerns and whose overuse can put additional pressure on them. Hence, this study aimed to i) develop and assess a nutritious and sustainable canned meal prototype using the Atlantic horse mackerel (Trachurus trachurus) (whose EU allowable-catch amounts have increased, particularly, in Iberian waters) and vegetables in light brine in terms of stability, sterility, and physicochemical and sensory properties over a 4-month period at room temperature and ii) evaluate its nutritional contribution for different population groups. After preparation, the meal was stored for one month at ≈20 °C and ≈40 °C (to simulate the 4 months). Although the pH was not stable, the meal was considered commercially sterile according to the challenge accelerated tests. Moreover, aging did not significantly affect the meal’s physicochemical and sensory properties. This innovative meal prototype can be claimed to be “low-fat”, “reduced in NaCl/Na”, a “source of protein, phosphorus, iron, selenium and vitamin D”, and “high in vitamin B12”. It proved to be both nutritious and appealing for consumption, with potential to be scaled up. Full article

Mercury (Hg) is a global health concern due to its prevalence, persistence, and toxicity. Numerous studies have assessed Hg concentrations in seafood, but variability in reported concentrations highlights the need for continued monitoring and stricter regulations. We measured total Hg (tHg) in 148 pre-processed, packaged seafood products purchased in Raleigh, North Carolina, using thermal decomposition–gold amalgamation atomic absorption spectrophotometry. Products were grouped into three categories based on trophic ecology and physiology: (1) tuna, (2) other bony fish, and (3) shellfish and squid. Among tuna, albacore had the highest average tHg (396.4 ng/g ± 172.1), while yellowfin had the lowest (68.3 ng/g ± 64.7). Herring (54.0 ng/g ± 23.2) and crab (78.2 ng/g ± 24.1) had the highest concentrations in the other two groups. One can of albacore exceeded the FDA action level of 1 part per million (1.3 ppm or 1300 ng/g). Brand differences were significant for both albacore and light tuna, with Brand 1 consistently showing higher Hg levels. Comparisons to FDA data (1990–2012) suggest Hg concentrations in tuna have remained stable over the past two decades. This study underscores the variability of Hg concentrations across species and brands and the need for continued monitoring to protect consumers. Full article

Epipelagic fish communities dominate fish assemblages and are an important part of marine ecosystems due to their high abundance, vertical migration behavior, and global distribution. Purse seine fisheries are key components of marine fisheries in the tropical Western and Central Pacific Ocean (WCPO), primarily targeting skipjack tuna (Katsuwonus pelamis, SKJ), yellowfin tuna (Thunnus albacares, YFT), and bigeye tuna (Thunnus obesus, BET). In this study, WCPO purse seine fishery data from 2014 to 2022, combined with environmental factor data, were used, and Mantel tests and correlation analysis were employed to analyze the diversity, fish coexistence mechanisms, and environmental responses of catch communities under the following two different fishing strategies: free–swimming schools (FSCs) and drifting fish aggregating devices (DFADs). Mantel tests indicated that nitrate (NO_3⁻), the Oceanic Niño Index (ONI), and pH significantly impact the diversity of the FSCs community, whereas NO_3⁻ significantly affects the diversity of the DFADs community. Based on the correlation analysis results, in the FSCs community, yellowfin tuna was positively correlated with bigeye tuna, and yellowfin tuna was negatively correlated with skipjack tuna and black marlin (Istiompax indica, BLM). In the DFADs community, yellowfin tuna was only positively correlated with skipjack tuna and bigeye tuna. In addition, species with high correlations were also positively correlated. The results of this study provide a theoretical basis for the biodiversity conservation of catch communities under two different purse seine fishing strategies in the WCPO. Full article

The mercury (Hg) present in ocean fish has caused concern regarding the effects of maternal consumption on child outcomes but it is now recognized that mothers that eat more ocean fish during pregnancy have children with higher social, scholastic, and IQ scores. These findings coincide with the current understanding of the mechanism of Hg toxicity which indicates ocean fish consumption will prevent rather than cause harm. High-Hg exposures sequester selenium (Se) and inhibit Se-dependent enzymes that prevent and reverse oxidative damage in the brain and support fetal brain development. However, aside from certain types of shark and other apex marine predators, seafood contains more Se than Hg and thus counteracts instead of contributing to Hg toxicity. This study evaluates the Hg and Se present in bigeye tuna, yellowfin tuna, albacore tuna, skipjack, swordfish, striped marlin, blue marlin, spearfish, mahimahi, wahoo, monchong, escolar, mako shark, and thresher shark to establish their health benefit values (HBVs). Positive HBVs (0.3–19.6), indicating a molar excess of Se over Hg, were found in 14 of the 15 species studied. Only mako shark uniformly contained Hg in excess of Se to produce a negative HBV (−16.4), indicating its consumption should be minimized during pregnancy. Full article

The large pelagic species play an important role in transferring energy in vast distant marine ecoregions. Results obtained report on extraordinary findings of important commercial species in southeast–south Brazilian waters, including the Southern bluefin tuna Thunnus maccoyii and the Pacific bluefin tuna Thunnus orientalis, an endemic species from the Pacific Ocean. These specimens were identified within the genomic description of 10 individuals randomly selected from the catch to evaluate the catch composition of pelagic longline fisheries off Brazilian waters. Most of the records were from T. maccoyii (6), followed by the Bigeye tuna T. obesus (2), Yellowfin tuna T. albacares (1), and T. orientalis (1). Yellowfin and Bigeye tuna are expected to be captured in the vicinity of the longline fishing areas. However, the unlikely presence of the cold-water T. maccoyii and the warm-water T. orientalis suggests a long migration from common species ranges that could be influenced by climate change. These results imply a readjustment of spatial management structures for these species. Full article

Environmental temperature declines significantly impact the physiological processes of marine organisms, particularly under the cool La Nina conditions, challenging yellowfin tuna (Thunnus albacares) aquaculture. Low temperatures affect fish metabolism and immune functions and can alter the gut microbiota composition, influencing health and growth. This study investigates the impact of low temperatures on the gut microbiota of juvenile yellowfin tuna. Fish were divided into a Low Temperature (LT) group (24 °C), an Ultra Low Temperature (ULT) group (18 °C), and a Control group (CG) (30 °C), with evaluations at 0, 12, 24, and 36 h using α-diversity analysis and microbial species composition. Results indicated a significant increase in the Ace index for the ULT group after 36 h of cold stress (p < 0.05), with no significant changes in the Shannon index. A decline in Proteobacteria and increases in Verrucomicrobiota and Firmicutes were observed in both LT and ULT groups. Additionally, both LT and ULT groups showed a significant rise in the Ace index at 36 h (p < 0.05), with a significant decrease in the Shannon index in the ULT group at 24 h. Furthermore, Firmicutes significantly increased at 12 h in both temperature groups (p < 0.05). These findings highlight the potential role of the gut microbiome in adapting yellowfin tuna to cold environments and provide microbial insights into their physiological adaptations, laying a foundation for further research and practical applications in aquaculture under cold conditions. Full article

Fisheries and aquaculture play a crucial role in global food security, yet species mislabeling remains a persistent challenge, undermining consumer trust and market transparency. Proper food labeling is essential for protecting public health due to the presence of unknown toxic or allergenic substances and preventing illegally sourced products from entering the market. Despite extensive research across Europe, seafood mislabeling in Croatia has remained unexplored. This study aims to provide the first comprehensive assessment of seafood labeling accuracy in Croatia, where fisheries are integral to the coastal economies and tourism. Using DNA barcoding of the COI gene, 109 seafood samples were collected over two years from various sources, including restaurants, markets, and fishing vessels, and analyzed for potential mislabeling. Results revealed a mislabeling rate of 3% among fish samples and 20% among cephalopods, with notable substitutions, such as the yellowfin tuna mislabeled as bigeye tuna and Bluefin tuna and the European squid mislabeled as Patagonian squid. Additionally, 38.5% of samples were partially labeled, while 32% lacked clear country-of-origin information, complicating traceability. While the findings align with the mislabeling rates in other European countries, this study underscores the ongoing challenges in seafood labeling compliance. Establishing standardized monitoring protocols will be essential for improving comparability and effectively addressing seafood fraud. Full article

Fish sustainability has become an ever more important issue in recent years, as increases in consumption are leading to overfishing practices, resulting in the depletion of the seas and environmental damage. Therefore, fish companies have been adhering to sustainability programs, although these sustainable practices are not well valued and thus well known by end consumers. Therefore, this study aimed to assess the impact of sustainability label information on the hedonic perception of a consumer group regarding two fish species threatened by overfishing: European anchovy (Engraulis encrasicolus) and Bluefin tuna (Thunnus thynnus). The approach used was a blind–expected–informed evaluation. The results showed a positive perception of the species with the sustainability label by recording higher informed hedonic scores than blind ones. Thus, in conclusion, fish sustainability positively influenced the consumers, increasing their liking scores from the blind to the informed session. This study can expand previous knowledge on environmental sustainability, especially fisheries sustainability, and understand the relationships between sustainability eco-labels and consumer behaviour. Full article

The Canary Islands, a Spanish archipelago off the coast of East Africa, have a longstanding historical connection to the fishing sector. Despite its cultural and ecological significance, the sector’s social, economic, and sustainable dimensions remain underexplored. This research contextualises the fishing industry in the Canary Islands and evaluates the impact of COVID-19. From 2012 to 2022, the sector contributed just 0.14% to the region’s GDP, compared to 3.75% nationally, a 3.5% difference, despite the high value of species like bigeye tuna and bluefin tuna. This disparity highlights the limited economic weight of local fisheries. This study also reveals how the pandemic exacerbated existing challenges, threatening the sector’s sustainability. However, traditional fishing practices in the Canary Islands, with their lower environmental impact, play a vital role in preserving marine ecosystems, combating climate change, and alleviating broader economic pressures. These findings underscore the need for targeted strategies to ensure the sector’s resilience and sustainability after the pandemic. Full article

Fish is a nutrient-rich food important for the well-being of all age groups. However, through fish ingestion, organisms are also exposed to various contaminants such as mercury, which can be biomagnified to reach the highest levels of concentration in predatory fishes. The aim of this study was to evaluate the consumption of fish and seafood products in the population of an Italian coastal region and to investigate the perception of risk by consumers. A closed-ended questionnaire was administered for this purpose. Regarding the habit of eating fish and seafood products, 92% of the interviewees reported consuming these regularly. Fresh, frozen, and canned products were eaten one to three times a week by 55.0%, 52.1%, and 65.6% of participants, respectively. Swordfish and tuna, species at high risk of methylmercury contamination, were consumed one or more times a month by 79.5% of respondents. Only 37.4% showed awareness of the possible health risk, with 81% citing chemical causes (e.g., methylmercury). Combined actions are needed to contain the risk of exposure to contaminants, such as mercury, through the ingestion of fish and seafood products, including greater consumer information on species to be limited, fisheries monitoring, and controls on contaminant emissions. Full article

The Indonesian maritime territory harbors a rich diversity of marine resources, making up approximately 37% of global fish species diversity. Tuna, particularly in Maluku Province, stands out as a vital economic asset with growing production and export numbers. Current practices for processing and evaluating tuna meat, however, face significant limitations due to basic infrastructure and reliance on manual inspection methods, leading to potential contamination risks and treatment identification errors. This research addresses these challenges by implementing an advanced deep learning solution based on convolutional neural networks (CNNs) to automatically identify three distinct treatment categories for tuna loin: No-Treatment, CO-Treatment, and CS-Treatment. Trained on a comprehensive image dataset, the model demonstrated exceptional performance with 95% accuracy. While field testing confirmed the model’s strong performance in correctly identifying treatment categories, occasional classification errors highlighted areas for improvement in data preprocessing. This study provides a significant step forward in automated fish processing assessment technology, offering a promising solution to longstanding challenges in the marine processing industry. Full article

The European Food Safety Authority (EFSA) monitors the presence and concentration of contaminants in food to mitigate health risks. EU legislation sets maximum levels of heavy metals in foods, including cadmium (Cd), lead (Pb), and total Hg (THg) in seafood, due to their toxicity. In the framework of official control, between 2014 and 2023, 5854 seafood samples were collected and 4300 analyses for THg, 3338 for Cd, and 2171 for Pb were performed using Inductively Coupled Plasma Mass Spectrometry (ICP-MS) and cold vapor atomic absorption spectrometry (CVAAS). The aim was to assess the proportion of contaminated foods in the dataset, the concentration of contaminants, and the potential health risks associated with their intake. Of the total samples analyzed, 142 (2.43%) were found to be non-compliant (n.c.). Concentrations exceeding the limits for Cd were primarily detected in cephalopods (n = 17), mainly squids. In contrast, Hg levels exceeded the limits in marine fish (n = 118), notably in swordfish (11.30% of n.c. samples among those analyzed for this species), sharks (6.48%), and tuna species (3.11%). Regarding Pb, only a single bivalve sample was found to exceed the maximum limits. A preliminary assessment of weekly exposure to Hg through swordfish consumption raised concerns about the frequent intake of marine top predators, particularly for vulnerable people. Full article

Tuna accounts for 20% of the output value of global marine capture fisheries, and it plays a crucial role in maintaining ecosystem stability, ensuring global food security, and supporting economic stability. However, improper management has led to significant overfishing, resulting in a sharp decline in tuna populations. For sustainable tuna fishing, it is essential to accurately identify the species of tuna caught and to count their numbers, as these data are the foundation for setting scientific catch quotas. The traditional manual identification method suffers from several limitations and is prone to errors during prolonged operations, especially due to factors like fatigue, high-intensity workloads, or adverse weather conditions, which ultimately compromise its accuracy. Furthermore, the lack of transparency in the manual process may lead to intentional underreporting, which undermines the integrity of fisheries’ data. In contrast, an intelligent, real-time identification system can reduce the need for human labor, assist in more accurate identification, and enhance transparency in fisheries’ management. This system not only provides reliable data for refined management but also enables fisheries’ authorities to dynamically adjust fishing strategies in real time, issue timely warnings when catch limits are approached or exceeded, and prevent overfishing, thus ultimately contributing to sustainable tuna management. In light of this need, this article proposes the RSNC-YOLO algorithm, an intelligent model designed for recognizing tuna in complex scenarios on fishing vessels. Based on YOLOv8s-seg, RSNC-YOLO integrates Reparameterized C3 (RepC3), Selective Channel Down-sampling (SCDown), a Normalization-based Attention Module (NAM), and C2f-DCNv3-DLKA modules. By utilizing a subset of images selected from the Fishnet Open Image Database, the model achieves a 2.7% improvement in mAP@0.5 and a 0.7% improvement in mAP@0.5:0.95. Additionally, the number of parameters is reduced by approximately 30%, and the model’s weight size is reduced by 9.6 MB, while maintaining an inference speed comparable to that of YOLOv8s-seg. Full article