Search Results (2,192)

Rochia nilotica is a tropical Pacific gastropod inhabiting shallow coral reef habitats and supporting important marine resources in Pacific island nations. In this study, we analyzed specimens collected from Weno Island, Chuuk Atoll, Federation States of Micronesia (FSM), using an integrative approach that combined morphological characteristics, molecular phylogenetics (COX1 and 16S rRNA), and complete mitochondrial genome analysis. While the Chuuk population exhibited morphological features consistent with R. nilotica, molecular data revealed substantial genetic divergence. Phylogenetic analyses based on the complete mitochondrial genome (17,664 bp) clustered the Chuuk specimen with Rochia virgata. Phylogenies inferred from concatenated COX1 and 16S rRNA gene sequences yielded congruent topologies, placing the Chuuk lineage within the Rochia clade but clearly separated from other R. nilotica populations in New Caledonia and Mo’orea Island, French Polynesia. This genetic divergence is likely driven by the long-term geographic isolation of Chuuk Atoll. The lagoon’s fringing reefs descend rapidly into waters exceeding 4000 m, which may act as a barrier to restricting larval dispersal. Combined with the extremely short planktonic larval duration of R. nilotica (approximately four days), such environmental isolation may promote the formation of a distinct gene pool. Despite morphological uniformity, the observed genetic divergence suggests that the Chuuk population may represent a cryptic species. Our study provides a complete mitochondrial genome and offers robust phylogenetic framework that provides an understanding of species boundaries within Rochia. These findings underscore the importance of integrating genomic and morphological data for accurate species identification and have implications for conservation and sustainable aquaculture practices in geographically isolated reef ecosystems. Full article

Marine Spatial Planning (MSP), the prevailing global governance paradigm for sustainable ocean development, confronts the critical challenge of integrating climatic uncertainty into its core processes. Reliance on the stationarity assumption compromises risk assessments for long-lifecycle assets within the Blue Economy, thereby impeding progress toward principal sustainability objectives. This article introduces and validates FARO (Framework for Adaptive Operational Risk Analysis), a methodological framework designed to operationalize the transition toward climate-smart MSP. The framework’s core innovation lies in furnishing a scalable quantitative structure that directly links high-resolution climatological projections with operational decision-making and capital planning, thereby converting climatic uncertainty into actionable operational risk indicators. Its applicability is demonstrated via a case study of Brazil’s emergent offshore wind industry (Southeastern Marine Region), analyzing impacts under the RCP 4.5 and RCP 8.5 scenarios (using INPE-Eta/CMIP5 regional projections). The findings quantify the critical role of technological resilience as a key adaptation variable, revealing a potential reduction in operational downtime from approximately 60% to 10% by enhancing operational capacity from Standard (SWH 2.0 m) to Flexible (SWH 2.5 m). In conclusion, the results indicate that FARO is a robust decision-support instrument, effectively bridging state-of-the-art regional climate science with participatory planning to foster genuinely sustainable and resilient maritime development. Full article

Urban flooding is a major challenge to sustainable development in rapidly urbanizing cities. This study applies an integrated approach that combines Sentinel-1 SAR data, geomorphological analysis, and the DPSIR (Drivers–Pressures–State–Impacts–Responses) framework to assess the relationship between urbanization and flooding in Hanoi during the 2010–2024 period (with Sentinel-1 time-series data for 2015–2024). A time series of Sentinel-1 images (2015–2024) was processed on Google Earth Engine to detect inundation and construct a flood frequency map, which was validated against 148 field survey points (overall accuracy = 87%, Kappa = 0.79). The results show that approximately 80% of newly urbanized areas are situated on geomorphologically sensitive units, including inside- and outside-dike floodplains, fluvio-marine plains, paleochannels, and karst terrains, characterized by low elevation and high flood susceptibility. Meanwhile, about 73% of the total inundated area occurs within newly developed urban zones, primarily in western and southwestern Hanoi, where rapid expansion on flood-prone terrain has intensified hazards. The DPSIR analysis highlights rapid population growth, land use change, and inadequate drainage infrastructure as the main pressures driving both the frequency and extent of flooding. To our knowledge, this is the first study integrating geomorphology, Sentinel-1, and DPSIR for Hanoi, thereby providing robust evidence to support sustainable urban planning and climate-resilient development. Full article

Chum salmon (Oncorhynchus keta) is undergoing aquaculture development in the Republic of Korea (ROK). Understanding its thermal biology, including the identification of optimal and suboptimal temperature ranges, is essential for sustainable aquaculture, particularly in a warming marine environment. In this study, we aimed to assess the optimal temperature range and high-temperature effects in chum salmon smolt reared at 10, 14, 18, and 22 °C for 6 weeks. Specifically, we evaluated growth performance, osmoregulatory capacity, health indicators, and endocrine and cellular stress responses after 3 and 6 weeks of exposure. After 6 weeks, the growth performance peaked at 18 °C, whereas both growth and body lipid reserve significantly declined at 22 °C despite sustained appetite. Growth was also significantly lower at 10 °C. Plasma osmolality and ion concentration did not change with increasing temperature. While hematocrit (Hct) and red blood cell count (RBCC) significantly decreased at 18 °C and 22 °C, hemoglobin concentration did not change significantly. The typical endocrine stress response was not observed; rather, cortisol levels decreased at 22 °C, whereas hepatic Heat Shock Protein (HSP)70 and HSP90 mRNA expressions were significantly upregulated at both 18 °C and 22 °C, with the markedly higher induction at 22 °C. These findings collectively indicate the onset of cellular stress at temperatures of 18 °C or higher. Despite the peak growth performance and competent osmoregulation performance at 18 °C, the concurrent induction of heat shock responses and decreases in Hct and RBCC suggest that the physiological optimum lies below 18 °C. Taken together, these findings suggest that maintaining rearing temperatures above 10 °C and below 18 °C is advisable to promote growth while minimizing cellular stress in aquaculture settings. Full article

Ports pose distinctive monitoring challenges due to harsh marine conditions, mixed construction typologies, and heterogeneous ground conditions. These factors complicate the routine use of satellite InSAR, especially when medium-resolution scatterers must be reliably attributed to specific assets for risk and asset management decisions. In current practice, persistent and distributed scatterer (PS/DS) points are often interpreted in map view without an explicit positional uncertainty model or systematic linkage to three-dimensional infrastructure geometry. We present an end-to-end Differential InSAR framework tailored to large ports that fuses medium-resolution Sentinel-1 Level 2 Co-registered Single-Look Complex (L2-CSLC) stacks with high-resolution airborne LiDAR at the post-processing stage. For the Port of Bahía de Algeciras (Spain), we process 123 Sentinel-1A/B images (2020–2022) in ascending and descending geometry using PS/DS time-series analysis with ETAD-like timing corrections and RAiDER tropospheric/ionospheric mitigation. LiDAR is then used to (i) derive look-specific shadow/layover masks and (ii) perform a whitening-transformed nearest-neighbor association that assigns PS/DS points to LiDAR points under an explicit range–azimuth–cross-range (RAC) uncertainty ellipsoid. The RAC standard deviations $({\sigma }_r,{\sigma }_a,{\sigma }_c)$ are derived from the effective CSLC range/azimuth resolution and from empirical height correction statistics, providing a geometry- and data-informed prior on positional uncertainty. Finally, we render dual-geometry red–green composites (ascending to R, descending to G; shared normalization) on the LiDAR point cloud, enabling consistent inspection in plan and elevation. Across asset types, rigid steel/concrete elements (trestles, quay faces, and dolphins) sustain high coherence, small whitened offsets, and stable backscatter in both looks; cylindrical storage tanks are bright but exhibit look-dependent visibility and larger cross-range residuals due to height and curvature; and container yards and vessels show high amplitude dispersion and lower temporal coherence driven by operations. Overall, LiDAR-assisted whitening-based linking reduces effective positional ambiguity and improves structure-specific attribution for most scatterers across the port. The fusion products, geometry-aware linking plus three-dimensional dual-geometry RGB, enhance the interpretability of medium-resolution SAR and provide a transferable, port-oriented basis for integrating deformation evidence into risk and asset management workflows. Full article

Background: Obesity is increasingly recognized as a metabolic disorder driven by gut microbiota dysbiosis and chronic low-grade inflammation within adipose tissue. Emerging evidence highlights the gut–adipose tissue axis as a critical mediator of energy balance and metabolic regulation. Marine algae—rich in polysaccharides, polyphenols, and carotenoids—offer bioactive compounds that modulate gut microbial composition and generate beneficial metabolites termed “postbiotics.” Objective: This review aims to comprehensively summarize current advances in understanding how marine-algal-derived postbiotics influence the gut microbiota–adipose tissue axis and contribute to obesity prevention and management. Methods: A structured literature search was conducted across PubMed, Scopus, Web of Science, ScienceDirect, and SpringerLink for studies published between 2015 and October 2025. Eligible studies included in vitro, in vivo, and human trials examining the effects of marine-algal compounds on gut microbiota composition, short-chain fatty acid (SCFA) production, adipose inflammation, and metabolic outcomes. Results: Marine-algal polysaccharides (fucoidan, alginate, laminarin, carrageenan, and ulvan) act as fermentable fibers that enhance SCFA production and enrich beneficial taxa such as Akkermansia, Lactobacillus, and Bacteroides, while reducing endotoxin-producing bacteria. Polyphenols and carotenoids (fucoxanthin, phlorotannins, astaxanthin) directly target adipogenesis, oxidative stress, and adipose browning. Animal studies consistently demonstrate reduced body weight, improved insulin sensitivity, and decreased inflammation following algae supplementation. Human trials—though limited—confirm safety and show microbiota modulation with modest weight loss. Conclusions: Marine-algal-derived postbiotics represent a promising, natural, and sustainable strategy to target the gut microbiota–adipose tissue axis in obesity. They offer multi-targeted mechanisms through microbial and host pathways, supporting their integration into functional food and nutraceutical development. Further clinical research and regulatory standardization are warranted to translate these findings into evidence-based interventions. Full article

Owing to its corrosion resistance, stainless steel is a sustainable alternative to carbon steel as a structural material in challenging seawater environments. Studies on carbon steel indicate that among all marine corrosion zones (i.e., atmospheric zone, splash zone, tidal zone, and immersed zone), the rate of corrosion is particularly high in the splash zone, above the seawater level, due to the recurrent splashing of seawater with high levels of oxygen and chloride content. Nevertheless, the information on the extent of localized corrosion (i.e., pitting and crevice corrosion) on stainless steel in the splash and tidal zones is scarce and, in most cases, limited to standard austenitic grades. In this work, we present the pitting and crevice corrosion results on lean duplex, duplex, and super duplex stainless steels after two years of field exposure in the North Sea (site at Heligoland South Harbour). The standard austenitic grade 1.4404 (316L) was also exposed as a reference material in atmosphere and splash zone conditions. Parallel exposure of coupons in splash, tidal, and immersed zones allows comparison of the extent of corrosion in each zone and enables proper material selection for structural applications in marine environments. Full article

In the Amazon basin, there are few terrestrial communication routes between cities, so river transport is often the only viable alternative for people and cargo. Although high-speed vessels are common in the region, they face operational challenges that endanger crews and passengers. Moreover, their use can impact the environment in various ways. This paper discusses operational difficulties related to the use of high-speed vessels in the Brazilian Amazon, and details possible environmental impacts, based on literature reviews and photographic information from field surveys in the state of Amazonas. The main operational challenges include interacting with complex flows, the possibility of colliding with fixed and moving objects, and the limitation of navigation routes. The main environmental impacts were classified as related to vessel motion, the propulsion system, and waste disposal. There is a need for increased innovation and research into marine applications and sustainability topics. Technical information must be disseminated more widely, including to remote regions. If the region’s sustainability is to be improved, riverine infrastructure must be enhanced and new technologies adopted. Full article

Coral reefs are crucial ecosystems for marine biodiversity but are increasingly threatened by anthropogenic pressures and climate anomalies. The 2016 global bleaching event resulted in widespread coral mortality, altering reef structure and benthic communities. Here, we examine the evolution of Maldivian reefs from 2015 to 2023 using long-term monitoring data to assess post-disturbance dynamics. Analyses of 26 benthic descriptors revealed severe impacts from thermal stress, with heterogeneous recovery patterns. Reef-building capacity, which reflects the reef’s accretion potential and is mainly sustained by primary (e.g., Acropora branching corals) and secondary constructors (e.g., Tridacna spp.), rebounded substantially, while binders (e.g., coralline algae) and bafflers (e.g., erect sponges) remained depleted. Among growth forms, fast-growing branching and digitate corals, despite substantial declines, drove rapid recovery. Massive corals were less affected and continued growing, while encrusting corals declined steadily over the period. Post-bleaching community composition shifted markedly toward increased abiotic cover and reduced coral dominance, with partial reversion by 2023. Despite the 2016 collapse in constructional capacity, most reefs exhibited notable recovery within seven years. These findings underscore the moderate yet promising resilience of Maldivian reefs, exceeding previous bleaching events, and emphasize the importance of long-term monitoring to understand ecosystem responses under accelerating climate stress. Full article

The abundant Argentine shortfin squid resource plays a key role in the Patagonian Large Marine Ecosystem, the Polar Frontal Zone Ecosystem, and the South Atlantic Subtropical Gyre Ecosystem. In this article, we analyzed the annual and monthly changes in catch per unit effort (CPUE) of Argentine shortfin squid with a spatial resolution of 0.25° × 0.25° and constructed three ensemble learning and two deep learning fishing grounds forecasting models using catch information and spatial–temporal and marine environmental data. The results of the study were as follows: 1. From 2016 to 2021, Argentine shortfin squid in the Southwest Atlantic experienced notable interannual fluctuations, with the resource showing an increase and then remaining stable from 2016 to 2018, a decline in 2019, and a substantial increase from 2020 to 2021. Seasonally, CPUE was low from November to January, rose significantly from February to May, and declined in June; 2. The XGBoost model had the best overall performance among the three tree models, achieving an average of 68.86% accuracy, 70.19% F1-score; 3. In the 2021 actual production data validation, the Fusion ResNet18 model achieved an average production data accuracy of 74.47%, F1-score of 73.85%; the Fusion 3DResNet18 model achieved an average production data accuracy of 81.27%, F1-score of 82.43%. This indicates that convolutional neural networks, particularly 3D versions, are more suitable than decision tree-based ensemble models for predicting Argentine shortfin squid fishing grounds. Highly accurate fishing grounds forecasts help enterprises save production costs while providing some reference for the sustainable development of fishery resources. Full article

Accounting for Gross Ecosystem Product (GEP) is a crucial approach for quantifying ecological value, assessing the contributions of ecosystems to human well-being, and supporting sustainable development decision-making. For the Pingtan Comprehensive Experimental Zone, an island-centered administrative region, we developed a GEP indicator system and accounting framework tailored to islands for integrated accounting of terrestrial and marine ecosystems. We used a functional value approach that combines biophysical models with statistical data and conducts physical and monetary accounting in two steps. The accounting methods and procedures were refined to exclude resource and labor inputs from production processes and eliminate external contributions. From 2015 to 2023, the GEP increased by 9.118 billion CNY, representing an increase of 133.03%. The total GEP exhibited a phased rapid–slow–rapid fluctuation pattern over time. The value structure shifted from being dominated by material supply services to being dominated by cultural services. The high-value areas of flood regulation exhibited a clear expansion trend, whereas water conservation and climate regulation showed a fragmented decline. Carbon sequestration, oxygen release, and soil retention remained relatively stable. The findings support evaluating the effectiveness of ecological conservation, implementing ecological compensation, and formulating sustainable development policies in the Pingtan Comprehensive Experimental Zone. Full article

Traditional shrimp maturation uses high water exchange, conflicting with sustainable farming and biosecurity, although broodstock production systems have been updated by the adoption of closed-cycle production. So, this study evaluated BFT for Penaeus vannamei broodstock maturation, comparing it against a conventional system. The research compared two treatments, BFT and CW, in three replicated tank systems. Each experimental unit was a circular fiberglass tank with 5.63 m³ working volume. BFT tanks involved a 3.12 m² mobile triangular cage for viewing and capturing mated females. Parameters monitored included water quality, reproductive performance and hemato-immunological responses. The BFT system resulted in greater water quality stability, significantly lower water consumption, and lower Total Ammonia Nitrogen (TAN) concentrations, indicating efficient ammonia recycling. Also, reproductive performance and most hemato-immunological parameters did not differ significantly between treatments. Although CW showed slightly higher broodstock survival and sperm viability, BFT males exhibited a significantly higher Total Hemocyte Count (THC). Overall, BFT is suitable for sustainable P. vannamei broodstock maturation, as it promotes stable environmental conditions without compromising reproductive or immunological performance. Further research is recommended, particularly regarding effects of zero-water-exchange on male shrimp and improvements on capture structures. Full article

In the naval sector, hydrofluorocarbons (HFCs) are the primary refrigerants in use. To face global environmental challenges, international treaties have established stringent regulations aimed at transitioning towards more sustainable alternatives. Natural refrigerants are proposed as valid solutions, with a particular focus on carbon dioxide (R744) due to its very low direct environmental impact and high safety. This paper evaluates the potential of using R744 as a refrigerant for refrigeration systems onboard cruise ships; based on the R744 innovative solutions currently proposed in the literature for cruise ship applications, the aim is to assess whether the transition to R744 would provide advantages in terms of energy performance and total environmental impact compared with conventional systems employing HFCs. The analysis includes a description of the conventional provision and air conditioning systems mounted onboard and innovative technologies utilizing R744 as a refrigerant, proposed in the literature. These systems are numerically analyzed and compared. The numerical results show that the exclusive use of R744 in onboard systems would significantly reduce the direct environmental impact compared with the current HFCs-based configurations. However, when considering the total impact, further technological advancements in R744 systems are required to achieve a reduction in indirect emissions as well. While progressing toward full R744 adoption, some promising pathways are proposed to enhance current system efficiency. Full article

The need for sustainable alternatives to petroleum-based plastic packaging has prompted interest in biodegradable biopolymer films. This study developed edible composite films using minimally refined chitosan from American lobster (Homarus americanus) shell waste combined with fish gelatin, glycerol, and sunflower oil. A Box–Behnken design within a response surface methodology (RSM) framework was used to investigate the effects of these formulation variables on ten key film properties, including mechanical strength, water sensitivity, barrier performance, and optical characteristics. High-quality empirical models (R² ≥ 0.88) captured nonlinear, synergistic, and antagonistic interactions among the components, revealing trade-offs between competing attributes. Simultaneous multi-response optimization identified balanced formulations suited to various food packaging needs, including perishable, fresh, and dry products. Experimental validation of selected formulations confirmed model predictions within 5% error under laboratory conditions. Up to 68% of the inhibition activity against Escherichia coli was retained in a few composite formulations when compared with neat chitosan films, thus supporting their potential for active packaging. The key highlight of the present work is the use of crude chitosan derived from lobster shell waste, a low-cost, sustainable alternative to highly purified commercial sources, demonstrating the practical viability of marine byproduct valorization. Overall, this study advances the development of high-performance, application-specific biopolymer films and highlights RSM as an effective tool for optimizing multifunctional edible packaging materials. Future work should focus on enhancing antimicrobial functionality, evaluating real-world performance, and assessing consumer acceptance to support industrial adoption. Full article