Search Results (271)

The red mullet (Mullus barbatus, Linnaeus 1758) is a commercially vital demersal species in the Eastern Aegean Sea, yet it is subjected to high fishing pressure. This study assesses the population dynamics, growth, and exploitation status of M. barbatus based on 64 commercial trawl surveys conducted between 2022 and 2024 in the Lesvos–Ayvalik region. Length-frequency data identified eight age classes, with dominant cohorts at ages 3 (26.4%) and 5 (25%). The von Bertalanffy growth model estimated an asymptotic length (L∞) of 27.9 cm and growth coefficient (k = 0.21 year⁻¹), indicating a slow growth rate. The estimated fishing mortality (F = 0.74) exceeded natural mortality (M = 0.44), producing an exploitation rate (E = 0.63) that indicates overfishing. The length at 50% capture (LC₅₀ = 10.92 cm) was substantially below the optimal biomass length (Le = 16.6 cm), highlighting gear selectivity issues. Net benefit analysis revealed optimal fishing at 50–85 m depth and during December. These findings underscore the urgent need for improved management, including gear modifications, seasonal closures, and reduced effort, to restore sustainability and protect juvenile fish in the Eastern Aegean trawl fishery. Full article

The environmental burden of widely used protein sources in animal feeds, such as soybean and fishmeal, has raised concerns about the sustainability of current livestock production systems. In response, alternative protein sources are being explored, with insect meal emerging as a promising candidate. This study conducted a comparative Life Cycle Assessment (LCA) of four compound pig feed formulations differing in protein composition, incorporating soybean meal, fishmeal, and Tenebrio molitor (insect) meal. The LCA followed ISO 14040/44 standards and applied both mass-based and protein-based functional units (FUs) to examine how FU choice influences environmental outcomes. Results showed that crop-derived ingredients, particularly soybean meal, drove most environmental burdens due to land use change and fertilizer inputs. Replacing soybean with insect meal led to impact reductions in key environmental categories. Insect meal’s scalability, efficient land use, and potential waste valorisation supported its role as a sustainable alternative. The study also highlighted key sustainability issues not assessed by LCA, such as overfishing and ecosystem disruption, associated with fishmeal. Overall, insect meal appeared to be a strong replacement for soybean and fishmeal, with soy substitution proving key to reducing environmental burdens. Finally, the protein-based FU was more relevant given the study’s nutritional focus. Full article

Background: Balancing nutrition security with environmental sustainability is a key priority in global food policy, with Sustainable Healthy Diets (SHDs) serving as a critical framework aligned with the UN Sustainable Development Goals (SDGs). Traditional Japanese cuisine reflects SHD principles through its emphasis on plant-based, seasonal, and minimally processed dishes. However, modern, globalized dietary patterns increasingly feature ultra-processed foods, raising concerns about health risks such as high sodium intake. Methods: This study adopts a novel dish-level content analysis of 120 contemporary recipes from NHK Today’s Cooking between 2023 and 2025, a TV program by Japan’s national public broadcaster that is widely regarded as reflecting the practices of Japanese home cooking, to examine how SHDs pillars—nutritional diversity (e.g., varied protein sources), environmental sustainability (e.g., low-carbon ingredients), and cultural continuity (e.g., traditional techniques)—are embedded in Japanese home cooking. Unlike macro-level consumption or nutrition data, this dish-level approach reveals how individual dishes embody sustainability through ingredient selection, preparation methods, and cultural logic. Results: Quantitatively, pork (33.3%) and seafood (19.2%) together dominated main protein sources, with minimal beef (2.5%) and a notable presence of soy-based foods (12.5%), supporting lower reliance on environmentally intensive red meat; mean salt content per person in main dishes was 2.16 ± 1.09 g (28.9% for men, 33.3% for women of Japan’s daily salt targets), while recipe patterns emphasizing fermentation and seasonal alignment highlight possible pathways through which Japanese dietary practices can be considered ecologically efficient. Simultaneously, the analysis identifies emerging challenges, encompassing environmental issues such as overfishing and public health concerns like excessive sodium consumption. Conclusions: By centering dishes as culturally meaningful units, and using media recipes as reproducible, representative datasets for monitoring dietary change, this approach offers a reproducible framework for assessing dietary sustainability in evolving global food systems. Full article

To ensure sustainable marine resource utilization, advanced monitoring methods are urgently needed to mitigate overfishing and ecological imbalances. Conventional fishing activity detection methods, including speed threshold-based approaches and Gaussian Mixture Models, often fail to accurately handle complex vessel trajectories, resulting in imprecise quantification of fishing effort and hindering effective monitoring of illegal, unreported, and unregulated (IUU) fishing activities. To address these limitations, we propose a spatiotemporal adaptive clustering and segmentation (STACS) framework for recognizing fishing activities. First, ST-DBSCAN clustering distinguishes concentrated fishing operations from transit movements. Second, an adaptive segmentation algorithm that incorporates heading stability and local density dynamically partitions trajectories into coherent segments, using spatiotemporal clusters as the basic units. Third, multiple features capturing temporal dynamics and spatial patterns are extracted to characterize fishing behaviors. Finally, an XGBoost classifier with run-length encoding post-processing converts point-level predictions to continuous fishing episodes. Experiments on fishing vessel trajectory datasets demonstrate that STACS outperforms conventional methods and advanced segmentation approaches, improving both point-level classification and segment-level coherence across diverse fishing scenarios. By enhancing IUU fishing detection and reducing classification inconsistencies, STACS provides valuable insights for marine conservation, policymaking, and fisheries management, bridging local behavioral dynamics with global trajectory analysis. Full article

Bigeye grunt (Brachydeuterus auritus) is a dominant fish species and mostly a major target species in both artisanal and industrial fisheries in the coastal waters of Sierra Leone. It was listed as near threatened in 2015 by the International Union for Conservation of Nature (IUCN) Red List. Although this species has been repeatedly assessed as overexploited by the Fishery Committee for the Eastern Central Atlantic (CECAF) in the majority of its range in the Eastern Central Atlantic, there have never been studies of stock assessment in the coastal waters of Sierra Leone. We conducted a study on the population dynamics of bigeye grunt in the coastal waters of Sierra Leone, which is crucial for completing the resource status of this species in the Eastern Central Atlantic. The results showed that the bigeye grunt had a wide distribution in the coastal waters of Sierra Leone, with significant spatiotemporal variation characteristics in biomass and abundance. The growth parameters of bigeye grunt varied across different months, but all E values were below 0.5, indicating that no overfishing occurred. These findings were further corroborated by the results of the Length-Based Bayesian Biomass Estimation method (LBB). The results of the Generalized Additive Model (GAM) show that there is a certain nonlinear relationship between the resource abundance of the bigeye grunt and both environmental factors and geographical locations, among which the influence of latitude is the greatest. This study posits that the bigeye grunt in Sierra Leone’s coastal waters exhibits moderate exploitation potential. The findings are anticipated to provide a scientific framework for informing evidence-based management strategies for this fishery resource. Full article

Ichthyoelephas longirostris, commonly known as pataló, is an endemic species from Colombia, categorized as endangered due to habitat degradation and overfishing. In this context, semen cryopreservation emerges as an effective strategy for its conservation. This study evaluated the damage caused by semen cryopreservation using a cryosolution composed of ethylene glycol (EG) at three inclusion levels (6%, 8%, and 10% v/v), skimmed milk powder (3% w/v), and glucose (6% w/v), all prepared in distilled water. A randomized experimental design was employed, with three treatments and a control (fresh semen), using pooled semen from different males (n = 12). Each sample was analyzed in triplicate. Sperm parameters were evaluated through computer-assisted analysis (CASA), and damage to the plasma membrane, mitochondria, and DNA was assessed via flow cytometry. Fresh semen showed low levels of membrane damage (9.6 ± 6.9%), mitochondrial damage (29.1 ± 16.8%), and DNA fragmentation (0.24 ± 0.13%). In thawed semen, the highest membrane damage was observed with 10% EG (79.3 ± 13.0%), while the highest DNA fragmentation occurred with 6% EG (22.5 ± 21.9%). The cryosolution composed of 8% EG showed the best results, with lower levels of damage in the evaluated structures. These findings suggest that the combination of 8% EG, 3% skimmed milk powder, and 6% glucose is an effective formulation to reduce cellular damage during I. longirostris semen cryopreservation, representing a useful tool for conservation programs of this species. Full article

Over recent decades, coastal wetlands in Jiangsu Province have faced multiple challenges, including overfishing, reclamation for aquaculture, wetland shrinkage, and biodiversity loss. Implementing wetland ecological restoration proves crucial for mitigating the degradation of coastal wetland ecosystems. Quantifying ecosystem service values and establishing rational ecological compensation standards provide essential references for ecological compensation research and alleviating human–land conflicts. The Jianchuan Ecological Restoration Project, located in Dafeng District of Yancheng City, Jiangsu Province, employs integrated wetland, woodland, and farmland construction to rebuild biodiversity, enhance water conservation capacity, and improve water purification functions, thereby significantly boosting regional ecological services. Results have demonstrated that the total ecosystem service value of this project reaches CNY 76.2896 million, with climate regulation representing the highest value (CNY 68.1496 million, 89.33% of total). Subsequent values include biodiversity maintenance (3.40%), water purification (3.31%), and food production (2.95%), while carbon sequestration/oxygen release (0.96%) and soil retention (0.05%) show relatively lower contributions. Notably, this project innovatively integrates carbon finance mechanisms through “carbon sink loans”, achieving efficient transformation of ecological value from “paper accounts” to market realization. This study establishes a scientific foundation for ecological restoration projects through ecosystem service-based value assessment and pathway exploration, offering both theoretical framework and practical references. Full article

Protecting threatened elasmobranch species despite limited data on their distribution and abundance is a critical challenge, particularly in the context of increasing human impacts on marine ecosystems. In the northeastern Atlantic, species such as the leafscale gulper shark, Portuguese dogfish, spurdog, and spotted ray are facing pressures from overfishing, bycatch, habitat degradation, and climate change. The OSPAR Commission has listed these species as threatened and/or declining and aims to protect them by reliably identifying suitable habitats and integrating these areas into Marine Protected Areas (MPAs). In this study, we present a spatial modelling framework using regression-based approaches to identify suitable habitats for these four species. Results show that suitable habitats of the spotted ray (25.8%) and spurdog (18.8%) are relatively well represented within existing MPAs, while those of the deep-water sharks are underrepresented (6.0% for leafscale gulper shark, and 6.8% for Portuguese dogfish). Our findings highlight the need for additional MPAs in deep-sea continental slope areas, particularly west and northwest of Scotland and Ireland. Such expansions would support OSPAR’s goal to protect 30% of its maritime area by 2030 and could benefit broader deep-sea biodiversity, including other vulnerable demersal species and benthic communities. Full article

Climate change is disrupting marine ecosystems, necessitating a deeper understanding of environmental and fishing-related impacts on exploited species. This study examines the effects of physical factors (temperature, thermal anomalies, salinity, seabed conditions), biogeochemical elements (pH, oxygen levels, nutrients, primary production), and fishing pressure on the biomass of commercially important species in the Alboran Sea from 1999 to 2022. Data were sourced from the Copernicus observational program, focusing on the geographical sub-area 1 (GSA-1) zone across three depth ranges. Generalized Additive Models were applied for analysis. Rising temperatures and seasonal anomalies have largely negative effects, disrupting species’ physiological balance. Changes in water quality, including improved nutrient and oxygen concentrations, have yielded complex ecological responses. Fishing indices highlight the vulnerability of small pelagic fish to climate change and overfishing, underscoring their economic and ecological significance. These findings stress the urgent need for ecosystem-based management strategies that integrate climate change impacts to ensure sustainable marine resource management. Full article

Overfishing represents one of the most alarming threats to marine conservation in the Mediterranean Sea. In particular, deep-sea trawl fishing can severely damage marine habitats that may take decades to recover due to their slow growth rates. Hence, monitoring the health and subsistence of deep-sea ecosystems in fishing hotspots is vital to understand the impacts of deep-sea fishing. This paper presents a methodological study to prepare an expedition in Sardinian (Italy) deep waters. The methodology is composed of three sections: first, it offers a comparative analysis of the proper technological mix to identify fishing hotspots pre-expedition; second, it simulates an in situ expedition to monitor the state of deep-sea ecosystems in proximity of the fishing hotspots identified; and third, it offers recommendations for data analysis and management post-expedition. This study offers a replicable methodology for advancing knowledge on the state of deep-sea ecosystems affected by trawl fishing. Full article

Skipjack tuna constitutes a crucial fishery resource in the Western and Central Pacific Ocean (WCPO) purse seine fishery, with high economic value and exploitation potential. It also serves as an essential subject for studying the interaction between fishery resource dynamics and marine ecosystems, as its resource abundance is significantly influenced by marine environmental factors. Skipjack tuna can be categorized into unassociated schools and associated schools, with the latter being predominant. Overfishing of the associated schools can adversely affect population health and the ecological environment. In-depth exploration of the spatial distribution responses of these two fish schools to environmental variables is significant for the rational development and utilization of tuna resources and for enhancing the sustainability of fishery resources. In sparsely sampled and complex marine environments, geographic similarity methods effectively predict tuna resources by quantifying local fishing ground environmental similarities. This study introduces geographical similarity theory. This study focused on 1° × 1° fishery data (2004–2021) released by the Western and Central Pacific Fisheries Commission (WCPFC) combined with relevant marine environmental data. We employed Geographical Convergent Cross Mapping (GCCM) to explore significant environmental factors influencing catch and variations in causal intensity and employed a Geographically Optimal Similarity (GOS) model to predict the spatial distribution of catch for the two types of tuna schools. The research findings indicate that the following: (1) Sea surface temperature (SST), sea surface salinity (SSS), and net primary productivity (NPP) are key factors in GCCM model analysis, significantly influencing the catch of two fish schools. (2) The GOS model exhibits higher prediction accuracy and stability compared to the Generalized Additive Model (GAM) and the Basic Configuration Similarity (BCS) model. R² values reaching 0.656 and 0.649 for the two types of schools, respectively, suggest that the geographical similarity method has certain applicability and application potential in the spatial prediction of fishery resources. (3) Uncertainty analysis revealed more stable predictions for unassociated schools, with 72.65% of the results falling within the low-uncertainty range (0.00–0.25), compared to 52.65% for associated schools. This study, based on geographical similarity theory, elucidates differential spatial responses of distinct schools to environmental factors and provides a novel approach for fishing ground prediction. It also provides a scientific basis for the dynamic assessment and rational exploitation and utilization of skipjack tuna resources in the Pacific Ocean. Full article

In the past two decades, little information has been updated to understand the resource status of the crab species Ovalipes punctatus in the East China Sea Region. In this study, we conducted surveys in 2018 and 2019 to identify the seasonal spatial distribution patterns of the economically important sand crab Ovalipes punctatus (De Haan 1833) in the southern Yellow and East China Seas. In the study area, the largest biomass of crabs was observed in the fishing grounds of Dasha and the Yangtze River mouth, and the second largest biomass was detected in the Jiangwai-Zhouwai area. Seasonally, the total biomass order in these areas was summer > autumn & winter > spring, and the mean average individual weight order was spring & summer > winter > autumn. These findings provided maps of the seasonal spatial distribution pattern of the species across seasons, which were then used in climate-change scenario models. Model predictions suggested that O. punctatus might migrate northward and offshore under climate warming conditions, and that the climate scenario SSP585-2100 might be the most negative case, respectively, for the habitat area of gain% minus loss%. These data can be used to develop robust and systematic regional fisheries resource management policies that consider adaptation measures to address the impact of environmental and climate change along China’s coasts and other areas in the world. Full article

The depletion of global fish stocks poses a major challenge to sustainable development, particularly in economies where marine resources are critical to livelihoods and food security. In this study, the relationship between economic development and the sustainability of fish stocks is examined using the Environmental Kuznets Curve (EKC). We use panel data from 32 economies between 2002 and 2020 and analyze the fish stock status indicator (EPI_FSS) from the Environmental Performance Index, which captures the proportion of national catches from overfished or collapsed stocks. Using a dynamic panel approach and the generalized method of moments (GMM), we investigate how the human development index (HDI) and other socio-economic factors influence changes in the state of fish stocks. Our results show a statistically significant inverted-U-shaped (∩-shaped) relationship between the HDI and the state of fish stocks, suggesting that the deterioration of fish stocks increases at lower levels of development, but improves beyond a certain threshold. In addition, higher levels of foreign direct investment (FDI), education, and research and development (R&D) spending are associated with better outcomes for fish stocks. These results suggest that while early economic growth may put pressure on marine resources, sustained investment in human capital, innovation, and global integration is critical to promoting long-term marine sustainability. Full article

This research investigated the temporal dynamics of the anthropogenic impact of fishing pressure on the resilience of the fish species Sarotherodon melanotheron (Rüppel, 1858) in the African Lake Toho, located in southwest Benin. The sampling and analysis of monthly length frequency data were conducted from April 2002 to March 2003 and from April 2022 to March 2023 using the FAO-ICLARM Stock Assessment Tool (FiSAT II software program (version 1.2.2.). The analysis of the S. melanotheron population in Lake Toho revealed a significantly diminishing resilience potential, reflected mainly in general reductions in both the average size and weight of individuals. There was a notable reduction in the size of Sarotherodon melanotheron individuals caught between 2002–2003 and 2022–2023, reflecting the increased pressure on juvenile size classes. Catches are now concentrated mainly on immature fish, revealing increasing exploitation before sexual maturity is reached. An analysis of maturity stages showed a decrease in the percentage of mature individuals in the catches (69.27% in 2002–2003 compared to 55.07% in 2022–2023) and a reduction in the number of mega-spawners (4.53% in 2002–2003 compared to 1.56% in 2022–2023). Growth parameters revealed a decrease in asymptotic length (from 32.2 cm to 23.8 cm) and longevity (from 9.37 years to 7.89 years), while the growth coefficient slightly increased. The mean size at first capture and optimal size significantly declined, indicating increased juvenile exploitation. The total and natural mortalities increased, whereas the fishing mortality remained stable. The exploitation rate remained high, despite a slight decrease from 0.69 to 0.65. Finally, the declines in the yield per recruit, maximum sustainable yield, and biomass confirm the increasing fishing pressure, leading to growth overfishing, recruitment overfishing, reproductive overfishing, and, last but not least, a decreasing resilience potential. These findings highlight the growing overexploitation of S. melanotheron in Lake Toho, compromising stock renewal, fish population resilience, sustainability, and production while jeopardizing local food safety. Full article

Silurus lanzhouensis is a large-sized commercial fish species endemic to the mid-upper reaches of the Yellow River, serving as a “Card of Aquatic Biological Species in the Yellow River”. However, due to factors such as overfishing and habitat changes, it has been listed as an endangered species. In order to protect and restore its wild resources, we conducted a detailed study for the first time from 2022 to 2024 on the age composition, growth characteristics, mortality rate, and current status of resource exploitation of the S. lanzhouensis population in the upper Yellow River. A total of 489 individuals underwent measurements for their total length (L) and body weight (W), with age determination conducted using lapillus otoliths. The collected samples exhibited a spectrum of total lengths spanning from 2.5 to 63.7 cm, body weights ranging from 0.11 to 1974.15 g, and ages ranging from 1 to 6 years. Further analysis of the length–weight relationships unveiled an allometric growth index (b) of 2.9562 for the overall samples, indicating an isometric growth pattern. Additionally, insights into the growth characteristics of S. lanzhouensis were provided by the von Bertalanffy growth function, revealing an asymptotic total length (L_∞) of 119.30 cm and a growth coefficient (K) of 0.1278 yr⁻¹. The growth characteristic index (φ) totaled 3.2598, suggesting a moderate growth rate in comparison to other Silurus species. The total mortality rate (Z) recorded for the population of S. lanzhouensis was found to be 0.5296 yr⁻¹. Through the application of three distinct methodologies on exhaustive samples, the average natural mortality rate (M) was calculated to be 0.3105 yr⁻¹. Consequently, the fishing mortality rate (F) for the entire sample set was determined to be 0.2191 yr⁻¹, leading to an exploitation rate (E) of 0.4137. Based on the survey findings, it is evident that the population of S. lanzhouensis has not been subjected to over-exploitation, attributable to ongoing stock enhancement. These results also provide foundational data for the protection and restoration of S. lanzhouensis in the upper Yellow River. Full article