Search Results (143)

The ten-year fishing ban on the Yangtze River aims to restore aquatic biodiversity and rebuild fishery resources. Megalobrama skolkovii, a key species in the basin, was investigated using 2024 data to provide a preliminary assessment of its population structure, stock dynamics, and early recovery. Age analysis (n = 243) showed that 1–6-year-olds were dominated by fish aged 3 (35%), with few older than 4, indicating moderate structural truncation. Growth parameters modeled by the von Bertalanffy Growth Function yielded L_∞ = 61.89 cm and k = 0.25 year⁻¹, with a weight–growth inflection age of 4.4 years. Natural mortality (M = 0.48 year⁻¹) was estimated using Pauly’s empirical formula, and total mortality (Z = 0.55 year⁻¹) was estimated from the catch curve analysis. While fishing mortality (F) was statistically indistinguishable from zero, a plausible low-intensity fishing scenario was explored to assess potential impacts of residual activities. Length-based indicators (LBIs) showed P_mat = 46.05%, P_opt = 9.51%, and P_mega = 6.88%, suggesting reproductive recovery but incomplete structural restoration. These preliminary findings reveal an asymmetrical recovery trajectory, whereby physiological improvements and enhanced recruitment have occurred, yet full structural restoration remains incomplete. This underscores the need for continued, long-term conservation and monitoring to support population resilience. Full article

The effects of changes in China’s final demand structure on its forestry sector and associated supply chains have not been thoroughly examined. This study aims to provide a detailed analysis of the quantitative relationships and underlying mechanisms between these interactive changes. Using China’s 153-sector input–output tables from the National Bureau of Statistics and applying a Leontief-based input–output model, we conducted scenario simulations through three distinct schemes, generating both quantitative and qualitative results. Our findings indicate that (1) For China’s forestry sector and its entire value chain to thrive, policymakers should boost consumer demand. This can better stimulate the development of forestry and the “agriculture-forestry-animal husbandry-fishery services” sector and related service industries; (2) Increased investment demand effectively stimulates the development of tertiary industries and secondary industries within the forestry supply chain and boosts the demand and production of intermediate products; (3) Changes in net exports have a significant impact on forestry and the forestry industry chain. To reduce dependence on foreign timber resources, China should strategically expand commercial plantation development; (4) Regarding intermediate product production, investment has a more pronounced effect on increasing total volume compared to consumption. Additionally, the Sino–US tariff disputes negatively impact the forestry industries of both countries. China needs to accelerate import substitution strategies for timber products, adjust international trade markets, and expand domestic consumption and investment to ensure the healthy and stable development of its forestry sector. Full article

Background: Fish escape events from aquaculture facilities are increasing and pose significant ecological, economic, and traceability concerns. Accurate methods to differentiate between wild, cultured, and escaped fish are essential for fishery management and seafood authentication. Methods: This study analyzed muscle tissue from Sparus aurata, Dicentrarchus labrax, and Argyrosomus regius using a multiomics approach. Heavy metals were quantified by ICP-MS, fatty acid profiles were assessed via GC-MS, and metabolomic and lipidomic signatures were identified using 1H NMR spectroscopy. Multivariate statistical models (MDS and PLS-LDA) were applied to classify fish origins. Results: Wild seabream showed significantly higher levels of arsenic (9.5-fold), selenium (3.5-fold), and DHA and ARA fatty acids (3.2-fold), while cultured fish exhibited increased linoleic and linolenic acids (6.5-fold). TMAO concentrations were up to 5.3-fold higher in wild fish, serving as a robust metabolic biomarker. Escaped fish displayed intermediate biochemical profiles. Multivariate models achieved a 100% classification accuracy across species and analytical techniques. Conclusions: The integration of heavy metal analysis, fatty acid profiling, and NMR-based metabolomics enables the accurate differentiation of fish origin. While muscle tissue provides reliable biomarkers relevant to human exposure, future studies should explore additional tissues such as liver and gills to improve the resolution of traceability. These methods support seafood authentication, enhance aquaculture traceability, and aid in managing the ecological impacts of escape events. Full article

Accurate and rapid aquatic organism recognition is a core technology for fisheries automation and aquatic organism statistical research. However, due to absorption and scattering effects, images of aquatic organisms often suffer from poor contrast and color distortion. Additionally, the clustering behavior of aquatic organisms often leads to occlusion, further complicating the identification task. This study proposes a lightweight object detection model, Mobile-YOLO, for the recognition of four representative aquatic organisms, namely holothurian, echinus, scallop, and starfish. Our model first utilizes the Mobile-Nano backbone network we proposed, which enhances feature perception while maintaining a lightweight design. Then, we propose a lightweight detection head, LDtect, which achieves a balance between lightweight structure and high accuracy. Additionally, we introduce Dysample (dynamic sampling) and HWD (Haar wavelet downsampling) modules, aiming to optimize the feature fusion structure and achieve lightweight goals by improving the processes of upsampling and downsampling. These modules also help compensate for the accuracy loss caused by the lightweight design of LDtect. Compared to the baseline model, our model reduces Params (parameters) by 32.2%, FLOPs (floating point operations) by 28.4%, and weights (model storage size) by 30.8%, while improving FPS (frames per second) by 95.2%. The improvement in mAP (mean average precision) can also lead to better accuracy in practical applications, such as marine species monitoring, conservation efforts, and biodiversity assessment. Furthermore, the model’s accuracy is enhanced, with the mAP increased by 1.6%, demonstrating the advanced nature of our approach. Compared with YOLO (You Only Look Once) series (YOLOv5-12), SSD (Single Shot MultiBox Detector), EfficientDet (Efficient Detection), RetinaNet, and RT-DETR (Real-Time Detection Transformer), our model achieves leading comprehensive performance in terms of both accuracy and lightweight design. The results indicate that our research provides technological support for precise and rapid aquatic organism recognition. Full article

Marine ranching, an emerging paradigm in sustainable fisheries, integrates technological, social, and ecological dimensions through a social–technical–ecological systems (STESs) framework to enhance ecosystem resilience and resource governance. This study proposes a comprehensive STESs-based framework and applies it to 15 demonstration sites in Guangdong Province, China, to explore the dynamic interplay among technological innovation, stakeholder engagement, fisheries governance, ecosystem health, biodiversity, and community participation. Through regression analyses and descriptive statistics, we quantified these multi-layered interactions. The study’s findings reveal significant correlations that underscore the importance of integrated approaches to marine ranching sustainability. Notably, stakeholder engagement is strongly linked to technological adoption (r = 0.58), suggesting that inclusive decision-making processes can drive the uptake of innovative, sustainable technologies. Furthermore, technological adoption is positively correlated with ecosystem health (r = 0.62), highlighting the potential for sustainable technologies to enhance marine ecosystem well-being. Community participation emerges as a critical factor in biodiversity conservation (r = 0.71), emphasizing the value of collaborative conservation efforts. Additionally, the strong predictive relationship between marine biodiversity and water quality (β = 0.85, p = 0.001) underscores the importance of preserving biodiversity for maintaining good water quality, which is fundamental to the health and sustainability of marine ranching systems. These insights collectively support the development of holistic management strategies that integrate social, technological, and ecological dimensions to promote the resilience and sustainability of marine ranching. These results underscore the crucial roles of participatory governance, sustainable fishery practices, and biodiversity protection in strengthening the ecological resilience of marine ranching systems. Full article

Microplastic pollution presents a significant and rising risk to both ecological integrity and the long-term viability of economic activities reliant on marine ecosystems. The Black Sea, a region sustaining economic sectors such as fisheries, tourism, and maritime transport, is increasingly vulnerable to this form of contamination. Mytilus galloprovincialis, a well-established bioindicator, accumulates microplastics, providing a direct measure of environmental pollution and indicating potential economic consequences deriving from degraded ecosystem services. While previous studies have documented microplastic pollution in the Black Sea, our paper specifically quantified microplastic contamination in M. galloprovincialis collected from four sites along the western Black Sea coast, each characterised by distinct levels of anthropogenic influence: Midia Port, Constanta Port, Mangalia Port, and 2 Mai. We used statistical analysis to quantify site-specific microplastic contamination in M. galloprovincialis and employed machine learning to develop models predicting accumulation patterns based on environmental variables. Our findings demonstrate the efficacy of mussels as bioindicators of marine plastic pollution and highlight the utility of machine learning in developing effective predictive tools for monitoring and managing marine litter contamination in marine environments, thereby contributing to sustainable economic practices. Full article

Mangrove ecosystems are vital for coastal protection, fisheries, biodiversity, and local livelihoods, yet they are increasingly threatened by land-use changes, climate impacts, and limited conservation funding. This study investigates how much local communities are willing to pay (WTP) to conserve the Chwaka Bay mangrove forest in Zanzibar. Using the Contingent Valuation Method (CVM) with a payment card approach, we conducted a structured household survey to assess both monetary contributions and the psychological and socioeconomic factors influencing them. This study is guided by Ajzen’s Theory of Planned Behavior (TPB), incorporating attitudes, subjective norms, perceived behavioral control, and mangrove knowledge. The results show that 68.2% of respondents are willing to pay for mangrove conservation, while 24.2% are not—mainly due to financial constraints or skepticism about fund use. Key drivers of WTP include perceived ecological and livelihood benefits, environmental awareness, and prior conservation involvement. Statistical validation using the Kaiser–Meyer–Olkin (KMO) test and Bartlett’s test of sphericity confirmed the reliability of the model. The findings demonstrate the value of combining behavioral theory with economic valuation to better understand and support community-based conservation strategies. This approach can inform policymakers in designing targeted, transparent, and inclusive mangrove protection programs. Full article

Fish meal (FM) and fish oil (FO) are vital components commonly used in feed formulations. However, their supply, which generally comes from capture fisheries, is being exhausted, necessitating the exploration of sustainable alternatives. In a two-part study, the first part evaluated the FM and FO derived from smoked salmon by-product (SSBP) over a 12-week accelerated shelf-life test, comparing their lipid oxidation, amino acid, and fatty acid profiles to those of commercial whitefish meal and oil. In the second part, the SSBP FM and FO were then included in three experimental feeds at 25%, 50%, and 100% inclusion levels. These feeds were tested on juvenile striped bass (Morone saxatilis) cultured in a recirculating aquaculture system (RAS). The results indicated that the quality of SSBP FM and FO was lower than the commercial product (less amino acids (23.98% vs. 60.30%) and omega-3 fatty acids (9.46% vs. 26.6%), respectively). SSBP FO exhibited high initial peroxide value (21.00 ± 0.00 meq/kg oil), with gradually increasing total oxidation value and p-Anisidine value during storage. Regarding the feeding trial, all fish showed signs of Mycobacterium marinum infection after one month. While there was no significant difference in feed palatability (p > 0.8559), the feed conversion ratio was less efficient for the 100% SSBP feed (1.44 ± 0.14) compared to commercial feed (1.36 ± 0.13), but these differences were not statistically significant. This study suggests that SSBP FM and FO can be used as supplements at lower levels (25% and 50%) without negatively affecting growth, feed efficiency, or survival. Our findings may be useful for enabling beneficial collaborations between smoked salmon processors, feed manufacturers, and striped bass farmers, therefore contributing to sustainability in aquaculture practices. Full article

The present study analyzed the growth pattern of the stingray Urotrygon chilensis caught as bycatch by the shrimp fishery in the southeastern Mexican Pacific. From January to December 2012, the thoracic vertebrae of 491 females and 205 males were collected. Female ages ranged from 0 to 14 years, whereas male ages ranged from 0 to 12 years. The marginal increment and edge analyses suggested the annual formation of growth bands in the vertebrae. The size-at-age data were analyzed using the multimodel inference approach; six candidate growth models were compared, including models with a theoretical age-at-zero total length, mean size-at-birth, and generalized models. Based on Akaike’s information criterion, the best statistical fit to the size-at-age data was the two-phase Gompertz growth model (k = −0.13, G = 1.59, $L_0$ = 10.40) for males and the two-parameter Gompertz growth model (k = 1.42, α = 0.15, $L_0$ = 10.90) for females. In this study, we compare the growth parameters among batoid species, finding that U. chilensis has a relatively short lifespan, slower growth, and that females are larger than males. Full article

The purpose of this study is to determine the current state of angler knowledge, opinions, awareness, and use of catch-and-release (C&R) best practices and to identify the main socio-economic factors that determine attitudes and willingness to use C&R among Polish anglers. Knowledge of this issue contributes to more effective management of fisheries and fish stocks. The research was conducted through an online survey form using a technique called CAWI (Computer-Assisted Web Interview). The questionnaire used consisted of 25 questions, including basic socio-economic questions, questions about seniority, frequency, location and method of fishing, and specific factual questions related to knowledge and practices regarding C&R. A total of 1574 respondents participated in the survey. The majority of respondents were male (97.5%). The survey showed that Polish anglers are overwhelmingly willing to practice C&R: 48.8% of respondents always and 44.0% often voluntarily release the fish they catch. Statistical analysis revealed a significant relationship between the use of this practice and the age of the angler (r = 0.46; p = 0.0001). Anglers under the age of 55 were the most likely to use C&R (p = 0.0097). The majority of respondents believe that C&R is important for improving fish stocks, but their knowledge and practices in this area have serious shortcomings. Inadequate knowledge of issues such as barotrauma or safe hook types, as well as inappropriate practices such as photographing and unhooking fish, can negatively affect their survival and ultimately the status of living water resources and ecosystem quality. These shortcomings may be due to inadequate education of anglers and fishery managers. Full article

Sea cucumbers are widely consumed as a delicacy or in eastern medicine across many Asian countries. Due to the depletion of traditional stocks, new species are increasingly harvested, including the Atlantic sea cucumber (Cucumaria frondosa), the most abundant, cold-water species found in the North Atlantic. This species is harvested in NAFO subdivision 3Ps off the south coast of Newfoundland and Labrador, Canada. As part of their respiration, stress response, and locomotion, sea cucumbers draw and retain oxygenated water within their body cavity, resulting in significant water content at landing. Historically, Fisheries and Oceans Canada (DFO) have applied a 23% deduction to the landed weight to account for this water retention. To validate this deduction, the authors conducted experiments across thirteen sampling events in 2019 and 2020. Randomized samples were collected during offloading and were categorized into three sizes of bin—small (x ≤ 150 g), medium (150 g < x ≤ 250 g), and large (x > 250 g)—and water loss was measured. Water loss was analyzed in relation to multiple factors, including processor, unloading method, year, license, month, fishing area, hold location, size, and processing method. Key findings included the following: (a) sea cucumbers typically contained more than 23% free water; (b) large and medium-sized specimens, which dominated landings, retained more free water; (c) water loss was highest for the samples collected from the top of the hold; (d) the unloading method influenced free water retention, as did the processing method used to cut the sea cucumbers; (e) license, processor, and fishing area had strong collinearity with other factors or were not found to be statistically significant; and (f) water loss appeared higher in 2020 than 2019, largely due to the increased use of vacuum transfer methods. Based on these findings, DFO revised the water retention allowance to 34%. Full article

YouTube has emerged as a powerful platform for digital content distribution, particularly in niche sectors such as fisheries and environmental sustainability. This study examines the impact of specific keywords on video visibility and engagement, focusing on fishery-related YouTube channels within the broader supply chain context. Using a statistical analysis with R software, this study isolates the influence of keywords while controlling for macro-characteristics such as video duration, title length, and description length. The findings reveal that while most structural video attributes do not significantly impact views, keyword optimization in video titles is crucial in improving discoverability. Additionally, a positive correlation between views and user engagement (likes) is confirmed, highlighting the role of interaction in content promotion. These insights provide actionable recommendations for content creators seeking to enhance their digital outreach while offering theoretical contributions to search engine optimization (SEO) and social media marketing strategies. Full article

The skate fauna in the Southwest Atlantic Ocean (SWA; 34–55° S) is represented by ~32 species, many of which share external features that have led to misidentifications and deficient fishery statistics. The use of DNA barcoding to discriminate SWA skate species was explored after 20 years of surveys. COI sequences were subjected to distance-based neighbor-joining (NJ), maximum likelihood (ML), barcode index number (BIN), automatic barcode gap discovery (ABGD), and nucleotide diagnostic character (NDC) analyses. For widely distributed species, a haplotype network was built. Overall, 187 specimens and 31 egg cases from 26 skate species were barcoded. NJ and ML analyses showed that nearly all species exhibited unique barcodes or clusters of closely related haplotypes, except for Psammobatis normani/P. rudis and Dipturus trachyderma/D. argentinensis. The first pair was discriminated by NCD. BIN analysis recovered 17 groups, whereas ABGD recovered 23, better reflecting taxonomic diversity. In summary, 24 species were resolved by COI. Phylogeographic signals were observed for Amblyraja doellojuradoi and Zearaja brevicaudata. Compiling our results with data from BOLD, almost all the species occurring in the area possess barcodes, contributing to completing and curating the BOLD reference library, which constitutes an important tool for resolving taxonomic issues, tracing fishery products, and performing eDNA biomonitoring. Full article

This study statistically classifies Korea’s communal fishing grounds (Maeul-Eojang) to inform tailored fisheries policy. We applied principal component analysis (PCA) to reduce 17 socio-economic and demographic indicators into five core factors, followed by K-means clustering to derive distinct types. The methodology was validated using Kaiser–Meyer–Olkin and Bartlett’s tests. Five communal fishery types were identified, ranging from well-managed, high-income communities to those in severe decline. The results show that about half of fishing communities fall into a “post-fishery” type with diminishing membership and income, while a quarter maintain robust fisheries through diversification. The typology is compared with previous fishing village classifications, and we discuss policy recommendations for each type—including co-management, tourism support, and targeted aid for declining communities. This research provides an empirical foundation for improving communal fisheries governance and sustaining coastal livelihoods. Full article

This study investigates seasonal and gender-related variations in some metal (Cd, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Se, and Zn) accumulation in black scorpionfish (Scorpaena porcus) from Izmir Bay (Aegean Sea, Türkiye) and assesses the associated human health risks. Samples, collected across four seasons from 2023 to 2024, were analyzed for element concentrations using inductively coupled plasma mass spectrometry (ICP-MS). Health risks were calculated using several models, including estimated weekly intake (EWI), target hazard quotient (THQ), total THQ (∑THQ), carcinogenic risk (CR), Se health benefit value (HBVSe), and the Metal Pollution Index (MPI). The results indicate that the consumption of black scorpionfish poses potential health risks, primarily due to the accumulation of manganese (Mn), lead (Pb), and mercury (Hg), which exceeded international permissible legal limits. Gender-based differences were observed, with males showing higher accumulation (p > 0.05); however, these differences were not statistically significant. In contrast, significant sex-based differences were identified specifically for cadmium (Cd), with concentrations exhibiting a statistically meaningful difference (p < 0.05). Seasonal variations were also apparent (p < 0.05). The carcinogenic risk (CR) analyses revealed that chromium (Cr) and nickel (Ni) levels surpassed carcinogenic risk thresholds. Furthermore, the MPI values provided additional insights into the overall metal pollution levels in the fish. These findings underscore the critical importance of monitoring metal pollution, revising fishery management strategies, and managing fish consumption to safeguard public health. Full article