Search Results (13,524)

To explore the optimization effects of fixed aquatic water treatment materials combined with immunomodulatory agents on the ecosystem and farming efficiency of Litopenaeus vannamei in high-water-level ponds, this study established experimental ponds (with fixed aquatic water treatment materials and feed supplemented with chitosan oligosaccharides) and control ponds (no fixed water treatment materials applied, fed with basal feed only). Through a comparative trial over a complete farming cycle, the study systematically analyzed changes in plankton community structure and diversity, water physicochemical factors, shrimp growth performance, immune indicators, and muscle nutritional composition. The results showed that in the experimental group, diatoms (Ditylum brightwellii and Skeletonema) dominated the plankton community, while the density of harmful blue-green algae (Oscillatoria and Trichodesmium) significantly decreased, and planktonic animal diversity improved in the later stages. Among the water physicochemical indicators, the experimental group exhibited a 50% reduction in nitrite levels by the later stages, significantly higher than the 33.33% reduction in the control group. Total ammonia nitrogen levels remained lower than those in the control group, with a smaller increase in the later stages. Total phosphorus levels were significantly lower in the experimental group after 80 days, and the later-stage decline in chemical oxygen demand was 11.65% higher than that in the control group. Shrimp body weight increased significantly by 13.23%, while hepatosomatic index, musculosomatic index, and immune enzyme (acid phosphatase and total antioxidant substances) activity also improved markedly. The content of unsaturated fatty acids (linoleic acid and oleic acid) in the muscles significantly increased. The study demonstrated that the combined application of fixed aquatic water treatment materials and chitosan oligosaccharide preparations can optimize the farming water environment, enhance shrimp growth performance and quality, and provide technical support for the ecological cultivation of Litopenaeus vannamei. Full article

Pseudotolithus elongatus is one of the most commercially important species supporting artisanal fisheries in Guinea-Bissau; however, its population biology and reproductive characteristics remain poorly understood, particularly in estuarine ecosystems. This study provides the first integrated biological characterisation of P. elongatus in the Cacine River Estuary, Guinea-Bissau, based on 1776 specimens collected through three independent sampling programmes. Length at first sexual maturity (L₅₀) was estimated using binomial generalised linear models (GLMs); length–weight relationships were assessed by ordinary least squares regression and analysis of covariance (ANCOVA); sexual size dimorphism was evaluated using a battery of parametric and non-parametric tests (ANOVA, Welch’s t-test, Kruskal–Wallis, Kolmogorov–Smirnov); and sex ratio was tested using chi-square goodness-of-fit tests with Yates’ continuity correction. Females attained sexual maturity at a significantly smaller size than males (L₅₀ = 224.9 mm vs. 306.8 mm), and both sexes exhibited positive allometric growth. Females attained larger body sizes and predominated in the largest length classes, confirming pronounced sexual size dimorphism. Reproductive activity occurred throughout the year, with a distinct spawning peak during the dry season (February–April), and the overall sex ratio remained close to parity despite significant variation among length classes and months. These findings provide a biological baseline to support evidence-informed fishery management of P. elongatus in Guinea-Bissau and highlight the need for long-term, standardised monitoring in the Cacine River Estuary. Full article

Long-term shoreline change on tropical islands is spatially heterogeneous, but alongshore contrasts remain insufficiently resolved. We quantified shoreline change along the 151.1 km eastern sandy coast of Hainan Island, China, from 1987 to 2025 using Landsat-derived visually interpreted shoreline proxies and the Digital Shoreline Analysis System across 1413 transects. The coast was broadly stable to accretional, with a mean linear regression rate (LRR) of 0.49 m/yr and a mean net shoreline movement (NSM) of 17.72 m. Under the uncertainty-aware classification, 28.0% of transects were stable, 42.1% accretional, 8.2% erosional, and 21.7% indeterminate. For descriptive comparison, the eight sectors were grouped into three broad alongshore zones: a stable northern zone (Beaches A–B), an accretion-dominated central zone (Beaches C–E), and a heterogeneous southern zone (Beaches F–H). The strongest accretion occurred at Beach D (LRR = 7.63 m/yr), whereas the strongest erosion occurred south of the offshore artificial island at Beach F (LRR = −3.97 m/yr). These contrasts show that coast-wide stability or accretion can mask localized erosion. The observed patterns were spatially associated with differences in headland-bay morphology, nearshore seagrass beds, engineering structures, estuarine processes, and lagoon-inlet settings. The findings support beach-sector monitoring and differentiated coastal management. Full article

Ecuadorian aquaculture plays an increasingly important role in food security, providing a sustainable complement to capture fisheries. Manabí constitutes a key economic sector that contributes to employment generation, income diversification, and supply of high-quality protein. However, the sector’s heterogeneity and limited legal registration of enterprises hinder the development of policies and targeted interventions. This study characterizes aquaculture enterprises in Manabí, integrating productive, technological, and socio-economic variables obtained from field surveys. Three distinct entrepreneurship patterns were identified: small-scale, informal farms cultivating native species with low technology but characteristics that may contribute to socio-ecological resilience; semi-formal producers operating with intermediate technology and mixed species; and freshwater shrimp farms operating at the largest relative scale within the sample, though still small-scale and family-based, with moderate technological development and market integration limited mainly to local and regional markets. The typology focused on a gradient in formalization, technological sophistication, and market orientation among enterprises. These findings provide a comprehensive understanding of aquaculture diversity in Manabí and offer a practical framework for differentiated policy design using a Strategic Producer Positioning Map. Strengthening formalization, technological innovation, environmental management, and social inclusion is essential to enhance the sector’s sustainability and competitiveness, contributing to sustainable blue economy development in coastal Ecuador. Full article

The Senegalese sole (Solea senegalensis Kaup, 1858) is a highly valuable species in European aquaculture and capture fisheries. Efficient monitoring of its populations is essential for sustainable management, yet traditional survey methods are invasive and labor-intensive. Environmental DNA (eDNA) analysis offers a powerful non-invasive alternative by detecting DNA fragments shed by organisms into the environment. In this study, we developed a species-specific TaqMan quantitative PCR (qPCR) assay targeting the mitochondrial cytochrome c oxidase subunit I (COI) gene to detect S. senegalensis eDNA. We evaluated assay performance, eDNA release, and persistence under controlled aquarium conditions. The assay demonstrated robust analytical sensitivity and specificity and showed an efficiency of 77.4%, an R² of 0.986, and an analytical limit of detection at the 10⁻⁵ dilution. Density had a statistically significant effect on the values observed (one-way ANOVA: F_3,16 = 3.903, p = 0.0287). To ensure accuracy, context-dependent operational quantification cycle (Cq) thresholds were defined: a stringent cutoff (Cq < 30) prevents false positives in complex marine environments, while a permissive cutoff (Cq < 36) maximizes detection in controlled settings. Aquarium trials confirmed that eDNA concentration correlates directly with fish density and accumulation time. Following fish removal, rapid eDNA degradation was observed, falling below strict quantifiable limits within 72 h, although trace signals persisted at late amplification cycles. This optimized qPCR protocol provides a foundational molecular tool that, pending further in situ validation, could support non-invasive S. senegalensis monitoring in ecological assessments and aquaculture management. Full article

Phytoplankton and zooplankton are critical basal resources in regulating aquatic material and energy fluxes. We investigated how environmental variables shape seasonal plankton abundance and diversity across nearshore zones in Eastern Guangdong, China. We identified 62 phytoplankton taxa (dominated by Bacillariophyceae at 88.52%) and 34 zooplankton species (dominated by calanoid copepods at 36.36%). Redundancy analysis (RDA) demonstrated that seasonal shifts in temperature, salinity, pH, dissolved oxygen, and dissolved nutrients (N, P, Si) significantly drive spatial community variability (Y ≥ 0.02). Dominant bioindicator species exhibited strong seasonal ties to environmental gradients; the diatom Skeletonema costatum strongly correlated with inorganic nitrogen during autumn, while the copepod Acartia centrura was heavily influenced by summer salinity and nutrient loads. Overall, phytoplankton diversity was higher than zooplankton diversity. These baseline findings regarding dominant copepods, diatoms, and eutrophic field parameters offer valuable insights for developing live feed alternatives in aquaculture and identifying bioactive substances for pharmaceutical applications. Full article

Whether zinc (Zn) and copper (Cu) bioaccumulation in the Pacific oyster (Magallana gigas) reflects toxicological stress or is an incidental consequence of growth remains unclear. We cultured three commercial triploid M. gigas stocks for approximately one year, sampling gill and hepatopancreas at the start and end of this period, when Zn/Cu burden was naturally low and high, respectively. Pooled samples from both time points were profiled by whole-transcriptome sequencing, enzyme activity and oxidative damage assays, qPCR validation, and protein–protein interaction network analysis. Transcriptome-wide changes in both tissues tracked the culture period, but growth and Zn/Cu burden were too highly collinear (r = 0.92–0.98) to separate statistically. Critically, of the four metals measured (Zn, Cu, iron [Fe], and manganese [Mn]), only Zn and Cu increased with growth, whereas Fe and Mn did not, indicating metal-specific rather than generalized accumulation. Superoxide dismutase (SOD) activity and the transcript abundance of its copper/zinc isoform (Cu/Zn-SOD) increased with growth in both tissues, whereas catalase (CAT) activity was unchanged and glutathione peroxidase (GPX) activity rose only in gill. Malondialdehyde (MDA), a marker of oxidative damage, increased in both tissues. Gill mounted a broader response than hepatopancreas, including upregulation of KEAP1 alongside downregulation of detoxification, proteostasis, and ribosome-related genes. Stock-level qPCR further revealed stock-dependent regulation of antioxidant genes in hepatopancreas. Together, these results indicate that Zn/Cu bioaccumulation in M. gigas co-varies with growth in a metal-specific manner, consistent with cofactor demand for Cu/Zn-SOD. The accompanying oxidative and proteostatic changes therefore more plausibly reflect growth physiology than an independent pollutant signal. Full article

Indonesia, as one of the world’s largest maritime nations, has substantial fishery potential in the Java Sea, yet fleet modernization remains limited. This study proposes a novel integrated framework that combines computer-aided vessel design with techno-economic feasibility analysis for a 30-GT steel fishing vessel as a replacement for traditional wooden fleets. The novelty lies in the simultaneous evaluation of technical design parameters and investment performance within a single framework tailored to small-scale fisheries. The vessel, with principal dimensions of 16 m (L), 4 m (B), 1.85 m (D), and 1.2 m (T), demonstrates adequate stability and operational capability. Financial results show positive NPV and an IRR above the benchmark, confirming technical and economic feasibility. The results confirm that 30-GT steel vessels provide a technically and economically feasible solution to support sustainable fishery development. Full article

The Greek seas have hosted a diversity of sharks and rays since antiquity, with Aristotle providing the earliest detailed descriptions in his History of Animals, while the first modern documented record dates back to 1858. Despite this long history of attention and the acceleration of research on elasmobranchs over the past two decades, information on their spatial distribution remains fragmented, with most studies focusing on biological and fisheries-related parameters at low taxonomic and/or spatial resolution. This is concerning given that over 50% of Mediterranean chondrichthyans are now threatened with extinction. The present study reconstructs the distribution of extant species in the Greek seas by integrating published literature, mass and social media, biodiversity platforms, citizen science programs, research projects, and national datasets. Although records were compiled from 1858 onwards, only those starting from 1942 contained sufficiently precise locality information to be georeferenced. The review yielded 5596 spatial presence records of initially 67 species; however, after data validation, 62 species were confirmed: 33 shark species, 28 batoid species, and 1 chimaera species, of which 54.8% were from research programs, 30.5% were from published research, and 14.4% were from citizen science and were previously unpublished. These records enrich knowledge of threatened and data-deficient taxa and may serve as a useful baseline for future analyses and distribution modeling, as well as for informing marine spatial planning and conservation prioritization efforts in the eastern Mediterranean. Full article

Mangrove ecosystems underpin the livelihoods of coastal and rural households across the tropics, yet how their ecosystem service (ES) values are associated with livelihood-strategy choices remains unevenly understood. Following a Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA)-guided protocol, this systematic review searched Web of Science and Scopus for studies published between 2016 and 2026 (database search was run on 27 May 2026); of the 353 records identified and 207 screened after removing 146 duplicates, 133 unique studies were retained; 95 of these contributed evidence to one or more of seven outcome themes, while 38 were retained as contextual or background evidence. The seven themes were graded using a hybrid Grading of Recommendations Assessment, Development and Evaluation (GRADE)/Confidence in the Evidence from Reviews of Qualitative Research (CERQual) approach (zero, high certainty; two, moderate certainty; five, low certainty). A structured assessment of meta-analytic feasibility across six candidate outcome domains found that no domain met the operational requirement of at least three independent studies reporting one outcome construct on a harmonisable metric with usable variance information; therefore, this review reports the direction, consistency, and certainty of associations rather than pooled-effect magnitudes. The corpus shows a pronounced value-epistemology asymmetry, with monetary valuation forming the largest single evidence theme (45 studies, approximately one-third of the corpus) and relational or indigenous framings remaining a smaller but substantive theme (20 studies, about 15%), meaning that household decision-making is incompletely captured. Evidence for mangrove–fishery production linkages and the coastal-protection/ecosystem-based disaster-risk-reduction function was the most consistent and was rated as moderate certainty. However, the fishery evidence provides the more direct connection to livelihood dependence, whereas most coastal-protection estimates are biophysical or aggregate and do not directly demonstrate household livelihood-strategy responses. The five remaining themes rest on low-certainty evidence, with welfare estimates spanning orders of magnitude and value-to-behaviour pathways weakly tested. Asian settings account for roughly half of the evidence (Southeast and South Asia together 45%, 60/133), while African, Latin American, and Pacific Island settings remain under-represented, limiting transferability. Evidence on bundled payments for ecosystem services, blue-carbon governance, and secure community tenure should therefore be treated as context-dependent options for prospective evaluation rather than as established prescriptions. The clearest research priority is quasi-experimental and longitudinal work linking elicited values to observed livelihood behaviour. Full article

In recent years, aquaculture, a critical pillar of global food security, has faced challenges including germplasm resource degradation, frequent disease outbreaks, and insufficient environmental adaptability. To address these issues, omics technologies—centered on genomics, transcriptomics, and related fields—are driving the transformation of aquaculture toward precision and intelligence by establishing a three-dimensional “genotype–phenotype–environment” knowledge network. In this review, we outline foundational applications of omics in aquaculture and highlight the characteristics and current applications of distinct omics approaches. Furthermore, we summarize three core application domains of omics in aquaculture: (1) genetic breeding via genomic selection (GS), gene editing, and multi-omics molecular dissection of economic traits; (2) disease prevention through host–pathogen interaction studies and microbial engineering; and (3) environmental assessment through multi-omics characterization of biological and ecological responses. Additionally, we identify challenges in applying omics technologies to aquatic breeding and database development. Overall, this review aims to provide aquaculture practitioners with actionable insights by enhancing understanding of omics-driven innovations in sustainable aquaculture advancement. Full article

Background/Objectives: Acinetobacter baumannii is a major cause of infections in Intensive Care Units (ICUs), driving mortality through high-level antimicrobial resistance. This study utilized whole-genome sequencing (WGS) to evaluate the phenotypic, genotypic and virulence features of carbapenem-resistant A. baumannii (CRAB), which has caused ventilator-associated pneumonia/tracheobronchitis (VAP/VAT) in the ICU of the University Hospital of Split, Croatia. Methods: Over 1 year, lower respiratory tract specimens from 79 VAP/VAT patients were analyzed. CRAB isolates were identified via MALDI-TOF MS and evaluated for antimicrobial susceptibility, and a representative subset underwent WGS and multilocus sequence typing (MLST). Results: Out of 106 specimens, 18 non-duplicate CRAB strains were isolated. Five isolates underwent genomic analysis, identifying two globally distributed, high-risk Pasteur lineages: ST2 and ST492. These lineages displayed distinct resistomes: ST2 carried bla_OXA-23 and bla_ADC-73, while ST492 harbored plasmid-borne bla_OXA-72 (Rep3-T1/AB082 cluster) and bla_ADC-30. All isolates shared aminoglycoside/macrolide-resistance genes, conserved efflux pumps, and virulence determinants (bau, bas, ent, bar) crucial for acinetobactin synthesis and respiratory colonization. Phylogenetic analysis confirmed regional circulation and genetic links to neighboring countries. Conclusions: This study highlights the evolutionary dynamics of endemic CRAB lineages in a Croatian ICU and their global dissemination, which poses a critical threat, demanding strict infection control and novel therapeutics. Full article

Background: Pancreas disease, caused by salmonid alphavirus subtype 3 (SAV3), remains a significant threat to Atlantic salmon (Salmo salar L.) aquaculture in Norway despite the widespread use of inactivated vaccines. Molecular adjuvants represent a promising strategy to improve vaccine efficacy by enhancing immune responses. Methods: In this study, we evaluated the immunological and protective effects of two transcription factors, gata3 and eomes encoded by plasmid DNA adjuvants in combination with a low-dose inactivated SAV3 vaccine. Atlantic salmon were immunized with inactivated virus alone or in combination with either gata3- or eomes-encoding plasmids, followed by SAV3 challenge. Vaccine performance was assessed by growth, antibody response (ELISA and virus neutralization assay), and histopathological scoring of heart and pancreas. Results: The effects of gata3 and eomes were context-dependent: eomes reduced pancreas lesions at 4 weeks post-challenge, while both plasmid-adjuvant groups showed improved growth at 10 weeks post-challenge compared to the plasmid control. Although antibody responses were increased in all vaccinated groups at 6 weeks post-immunization, the plasmid control performed comparably to the GATA3 or EOMES groups, and no significant differences were detected in the virus neutralization test. Interestingly, the empty plasmids given to control fish exhibited immunostimulatory activity, warranting further investigation. In vitro and in vivo fluorescence microscopy confirmed expression of the transcription factors in transfected cells and at the injection site. Conclusions: Our results suggest that transcription factor-encoding plasmids can provide selective adjuvant effects, while also highlighting the potential that plasmid DNA can have as adjuvants in fish vaccine development. Full article

Indonesia has significant fisheries potential; however, limited cold chain infrastructure at small-scale fishing ports contributes to post-harvest losses and quality degradation of fishery products. This study presents the design and techno-economic assessment of a modular portable cold storage unit for tuna fisheries integrated with renewable energy systems. The system (7 × 3 × 5 m) uses polyurethane sandwich panels and requires a maximum cooling load of 6.14 kW with peak power consumption of 7.93 kW. The estimated capital cost is approximately USD 34,100, while the operational cost is about USD 198 per cycle. A comparative analysis using the Levelized Cost of Energy (LCOE) method indicates that diesel generators provide the lowest cost at approximately USD 0.56/kWh, whereas standalone photovoltaic (PV) systems exhibit the highest cost at around USD 0.89/kWh. However, hybrid PV systems offer the best balance between cost efficiency and environmental performance by reducing carbon emissions. The results demonstrate that integrating hybrid renewable energy into modular cold storage enhances cold chain reliability, reduces fish losses, and supports sustainable coastal development. This approach contributes to low-carbon fisheries infrastructure and aligns with global sustainability and renewable energy transition goals. Full article

Marine mammal Bycatch Reduction Devices (BRDs) can result in the escape of target fish species. In the present study, a modified single-layer codend configuration developed from previous studies was evaluated using BRDs with guide net angles of 30° and 45°. Catch was collected separately from the codend and the BRD cover to estimate catch loss rates and characteristics. For caught species, catch loss rates based on the number and weight of individuals were 9% and 13% for herring with the 30° guide net and 16% and 18% with the 45° guide net, respectively. For Korean pomfret, catch loss rates were 24% and 23% at 30° and 4% at 45°. These results suggest that further modification of BRD is necessary. In contrast, catch loss rates of mackerel with the 30° guide net reached 56%, whereas hairtail showed loss rates of 60% and 65% with the 45° guide net. Underwater observations indicated that catch loss was influenced by swimming behavior and entanglement with the guide net. Despite the modification of the codend to a single layer, the present study still observed high catch loss rates. However, no bycatch of marine mammals occurred during the experimental operations. Full article