Search Results (383)

Brown algal forests (Cystoseira sensu lato) are key habitat-forming components of temperate rocky coasts but have experienced widespread decline across the Mediterranean Sea. This study investigates the current distribution and potential future shifts in brown algal forests across the Adriatic Sea under ongoing climate change. We combined non-destructive field-based mapping along the Slovenian coastline with remote-sensing products and spatial environmental predictors to model basin-wide habitat suitability. A multiscale geographically weighted regression (MGWR) framework was applied to account for spatial non-stationarity and to explicitly capture the fact that environmental drivers of habitat suitability operate at different spatial scales—an assumption that global models such as GAM or standard GWR cannot adequately address. Habitat suitability maps were generated for present-day conditions and projected under mid- and late-century climate scenarios. The results reveal pronounced latitudinal gradients, identify areas of ongoing canopy decline in the northern Adriatic, and highlight parts of the southern Adriatic as potential climate refugia. Overall, the study demonstrates a likely north–south contraction of suitable habitat for brown algal forests and underscores the value of multiscale spatial modelling for informing marine spatial planning, conservation prioritization, and climate-adaptive restoration under European policy frameworks. Full article

Under the requirements of the EU Nature Restoration Regulation, significant investment in the restoration of marine and coastal ecosystems will be necessary in EU Member States. A certain level of knowledge among the population will be required to ensure authorities have the required social license to pursue marine ecosystem restoration activities, and awareness raising campaigns will likely be a part of the body of actions taking place to support the delivery of the EU Nature Restoration Regulation. This survey assesses the baseline awareness, attitudes and support for marine and coastal restoration amongst the Irish adult population. Relatively low levels of awareness of both restoration initiatives and the regulation are documented, with approximately 15% of respondents aware of restoration activities and 19% aware of the regulation. While distance to the coast isn’t always strongly correlated with awareness and support, connection to the marine—represented by visiting the coast and being concerned about the marine environment—is strongly correlated with these metrics. The results indicate that information campaigns around marine and coastal restoration should attempt to highlight the benefits society receives from the marine and coastal environment and foster a sense of connection with it. Full article

Underwater optical images are the primary carriers of underwater scene information, playing a crucial role in marine resource exploration, underwater environmental monitoring, and engineering inspection. However, wavelength-dependent absorption and scattering severely deteriorate underwater images, leading to reduced contrast, chromatic distortions, and loss of structural details. To address these issues, we propose a U-shaped underwater image enhancement framework that integrates Swin-Transformer blocks with lightweight attention and residual modules. A Dual-Window Multi-Head Self-Attention (DWMSA) in the bottleneck models long-range context while preserving fine local structure. A Global-Aware Attention Map (GAMP) adaptively re-weights channels and spatial locations to focus on severely degraded regions. A Feature-Augmentation Residual Network (FARN) stabilizes deep training and emphasizes texture and color fidelity. Trained with a combination of Charbonnier, perceptual, and edge losses, our method achieves state-of-the-art results in PSNR and SSIM, the lowest LPIPS, and improvements in UIQM and UCIQE on the UFO-120 and EUVP datasets, with average metrics of PSNR 29.5 dB, SSIM 0.94, LPIPS 0.17, UIQM 3.62, and UCIQE 0.59. Qualitative results show reduced color cast, restored contrast, and sharper details. Code, weights, and evaluation scripts will be released to support reproducibility. Full article

Oil spills remain among the most severe anthropogenic threats to marine ecosystems, with consequences that span ecological, socio-economic, and human health domains. While numerous studies have investigated individual accidents such as Exxon Valdez, Prestige, and Deepwater Horizon, systematic comparative analyses across multiple large-scale incidents remain limited. This review addresses this critical gap by synthesizing findings from fourteen major oil spills worldwide. It examines the roles of oil type and environmental conditions, emphasizing impacts on fish, seabirds, shoreline habitats, and benthic organisms, as well as on long-term ecosystem recovery. Across cases, coastal waters, shorelines, and benthic communities consistently emerged as the most impacted habitats, reflecting both the persistence of oil in nearshore environments and the challenges of long-term restoration. Biologically, all trophic levels were affected: plankton, fish, seabirds, and benthic invertebrates were highly vulnerable, while marine mammals and reptiles suffered population-level effects. By integrating cross-case evidence, this review highlights recurring patterns, key uncertainties, and long-lasting ecosystem disruptions that persist decades after acute events. The Deepwater Horizon spill stands out as the most ecologically severe incident, whereas earlier spills such as Exxon Valdez, Erika, and Prestige remain benchmarks for ecological damage. Thus, this state-of-the-art review provides the most comprehensive comparative assessment of oil spill impacts to date and offers technical recommendations for enhancing preparedness, response, and resilience in the face of future spills. Full article

Although marine forest restoration projects have been widely implemented along the Korean coast, most evaluations have relied on simple structural indicators such as seaweed coverage or biomass, leaving functional responses of benthic macrofaunal communities largely unexplored. This study examined the effects of marine forest restoration on the functional structure of macrozoobenthic communities at development sites along Korea’s eastern coast in 2021 and 2024. Seaweed biomass increased significantly in 2024 compared to that in 2021, and this increase in seaweed biomass showed a clear positive correlation with increases in species number, density, and biomass of macrozoobenthos. Changes in feeding types of macrozoobenthic communities were remarkable, with grazer density increasing most sharply, followed by carnivores, omnivores, and suspension feeders. Red algal biomass was also positively correlated with suspension feeders and grazers, suggesting that seaweed mediated habitat and secondary food-web structures beyond providing simple food resources. These results indicate that seaweed habitat restoration plays an important role in recovering the functional diversity and feeding guild composition of macrozoobenthic communities and demonstrates the potential of using both species and functional diversity indicators to evaluate the effectiveness of marine forest restoration projects in Korea. Full article

Cadmium (Cd) is a typical pollutant with strong toxicity even at low concentrations. In the marine environment, Cd is a problem of magnitude and ecological significance due to its high toxicity and accumulation in living organisms. The clam Meretrix meretrix is a useful bioindicator species for evaluating heavy-metal stress. This study investigated the extent of recovery from Cd²⁺-induced oxidative and immune impairments in M. meretrix gills achieved by short-term depuration. Clams were exposed to 3 mg/L Cd²⁺ for six days or three days followed by three days of depuration, and the Cd contents, morphological structure, osmoregulation, oxidative stress, and immune responses in the gills were evaluated. The results showed that gill Cd contents increased with exposure, reaching 9.857 ± 0.074 mg·kg⁻¹ on day 3 but decreased slightly to 8.294 ± 0.056 mg·kg⁻¹ after depuration, while reaching 18.665 ± 0.040 mg·kg⁻¹ on day 6 after continuous exposure. Histological lesions, including lamellar fusion, hemolymphatic sinus dilation, and ciliary degeneration, partially recovered after depuration. Reactive oxygen species (ROS) and malondialdehyde (MDA) levels decreased significantly, while DNA-protein crosslinking rate (DPC) and protein carbonyl (PCO) showed minor reductions. Total antioxidant capacity (T-AOC) and the activities of Ca²⁺/Mg²⁺-ATPase (CMA), cytochrome c oxidase (COX), succinate dehydrogenase (SDH), and lactate dehydrogenase (LDH) increased by over 10% during depuration, though these changes were not statistically significant. Lysozyme (LZM) activity and MT transcript levels increased progressively with Cd exposure, indicating their suitability as biomarkers of Cd stress. Acid and alkaline phosphatase (ACP, AKP) activities and Hsp70 and Nrf2 mRNA transcripts exhibited inverted U-shaped response consistent with hormetic response. ACP and AKP activity levels rose by more than 20% after depuration, suggesting partial restoration of immune capacity. Overall, Cd exposure induced oxidative damage, metabolic disruption, and immune suppression in M. meretrix gills, yet short-term depuration allowed partial recovery. These findings enhance understanding of Cd toxicity and reversibility in marine bivalves and reinforce the usage of biochemical and molecular markers for monitoring Cd contamination and assessing depuration efficiency in aquaculture environments. Full article

This paper presents a validated, data-driven framework for the sustainable rehabilitation of corrosion-damaged marine infrastructure, demonstrated through a comprehensive study on a historic coastal structure. The implemented three-phase methodology—integrating advanced condition assessment, evidence-based intervention design, and rigorous performance validation—successfully addressed severe chloride-induced deterioration. Diagnostic quantification revealed that 30% of the primary substructure was severely compromised, with chloride concentrations reaching 1.94% by weight (970% above the corrosion threshold) and half-cell potential mapping confirming a >90% probability of active corrosion in critical elements. Guided by this data, a synergistic intervention combining galvanic cathodic protection, high-performance coatings, and structural strengthening was deployed. Post-repair validation confirmed exceptional outcomes: a complete electrochemical repassivation (potential shift from −385 mV to −185 mV), a 97.3% reduction in chloride diffusion rates, a 250% increase in surface resistivity, and the restoration of structural capacity to 115% of design specifications. The framework achieved a 65% reduction in projected lifecycle costs while establishing a new paradigm for preserving marine infrastructure through evidence-based, multi-mechanism strategies that ensure long-term durability and economic viability. Full article

As a major export crop in China, Saccharina japonica cultivation suffers from significant economic losses due to disease outbreaks, with pathogen identification remaining a critical bottleneck for mariculture. In this study, a dominant bacterial strain, LJ53, was isolated from the diseased farmed S. japonica. Artificial challenge assay confirmed that this strain is the direct causative agent of bleaching symptoms on sporophytes. Based on morphological characteristics and 16S rRNA gene-based phylogeny, it was identified as Pseudoalteromonas agarivorans LJ53. Ultrastructural observation revealed that this strain destroyed host cells and caused typical pathological changes such as chloroplast disintegration. Interestingly, metagenomic analysis showed no significant difference in the relative abundance of this pathogen between healthy and diseased S. japonica tissues. However, the co-occurrence network of the disease community exhibited increased connectivity, altered modularity, and features characteristic of microbial dysbiosis. This dysbiosis disrupts the water ecological balance by destabilizing microbial symbiosis and nutrient cycling, which are essential for overall ecosystem resilience. As a result, these imbalances can exacerbate disease transmission and weaken the self-regulating capacity of marine environment, highlighting the need for integrated management strategies to restore equilibrium. These findings provide a theoretical basis for elucidating the mechanisms of bacterial diseases in S. japonica and developing future control strategies. Full article

Rapid urbanization has intensified ecological problems such as landscape fragmentation and biodiversity decline, underscoring the need to maintain regional ecological integrity. The construction of ecological security patterns and the optimization of ecological restoration areas are crucial for addressing these ecological issues. However, research on how to couple ecological security patterns with ecological risk assessment to scientifically identify priority areas for ecological restoration and guide spatially targeted restoration remains insufficient. To address this gap, we investigated Liaoning Province by integrating morphological spatial pattern analysis, landscape connectivity assessment, and ecosystem service hotspot analysis to identify ecological sources. We then applied the minimum cumulative resistance model and circuit theory to extract ecological corridors, constructing a comprehensive ecological security pattern. Integrating landscape ecological risk assessment with ecological security patterns established a conservation and restoration-oriented ecological security framework. The results show that the ecological security pattern comprises 40 ecological source patches and 89 potential ecological corridors. Ecological sources encompass a total of 17,628 km² (approximately 12% of the province), primarily comprising water bodies, grasslands, shrublands, and forests. The ecological corridors span a total of 3533.9 km, with an average length of 39.7 km. We also identified 139 ecological pinch points and 109 ecological barrier points. Integrating these findings with landscape ecological risk zoning delineates ecological restoration zones, revealing a spatial pattern characterized by east–west differentiation and north–south continuity. This ecological conservation and restoration network provides a clear spatial guide and a robust scientific foundation for territorial spatial planning, ecological conservation, and restoration efforts. Full article

Diabetes mellitus represents one of the main health challenges worldwide, characterized by hyperglycemia and long-term serious microvascular and macrovascular complications. Marine organisms are a promising reservoir of bioactive metabolites for developing effective antidiabetic therapies with fewer side effects. The sea urchin Tripneustes gratilla (T. gratilla) is widely distributed in the Red Sea, with limited reports of its pharmacological activities and chemical characterization. In this study, a nanosuspension formulation of T. gratilla extract (T. gratilla-NS) was developed to enhance the bioavailability of its bioactive constituents. This study investigated the antidiabetic potential of T. gratilla extract through an integrated approach encompassing chemical profiling of the extract, assessment of its alcoholic extract for in vitro inhibitory effects on α-amylase and α-glucosidase, and in vivo evaluation of T. gratilla-NS in an alloxan-induced diabetic rat model. We found that the alcoholic extract showed potent inhibitory action toward α-amylase with IC₅₀ 5.31 ± 0.05 µg/mL and moderate inhibitory activity toward α-glucosidase with IC₅₀ 21.36 ± 0.06 µg/mL. T. gratilla-NS significantly increased insulin levels, reduced blood glucose levels, and restored pancreatic damage. Furthermore, it enhanced the levels of superoxide dismutase and total antioxidant capacity with a concomitant decrease in malondialdehyde concentration in pancreatic tissue. The observed activities could be attributed to a wide array of diverse compounds, terpenes, mainly sesquiterpenes, diterpenes, steroids, and polyunsaturated fatty acids detected by GC-MS, compounds with a phenolic nucleus equal to 54.26 ± 1.27 mg. GAE/g of extract. This research highlights the dual role of T. gratilla-NS in combating diabetes and subsequently attenuating its associated complications. Full article

The development of detection and identification technologies for biofouling organisms on marine aquaculture cages is of paramount importance for the automation and intelligence of cleaning processes by Autonomous Underwater Vehicles (AUVs). The present study proposes a methodology for the detection of fouling shellfish on marine aquaculture cages. This methodology is based on an improved version of a symmetric Faster R-CNN: The original Visual Geometry Group 16-layer (VGG16) network is replaced with a 50-layer Residual Network with Aggregated Transformations (ResNeXt50) architecture, incorporating a Convolutional Block Attention Module (CBAM) to enhance feature extraction capabilities; In addition, the anchor box dimensions must be optimised concurrently with the Intersection over Union (IoU) threshold. This is to ensure the adaptation to the scale of the object; combined with the Multi-Scale Retinex with Single Scale Component and Color Restoration (MSRCR) algorithm with a view to achieving image enhancement. Experiments demonstrate that the enhanced model attains an average precision of 94.27%, signifying a 10.31% augmentation over the original model whilst necessitating a mere one-fifth of the original model’s weight. At an intersection-over-union (IoU) value of 0.5, the model attains a mean average precision (mAP) of 93.14%, surpassing numerous prevalent detection models. Furthermore, the employment of an image-enhanced dataset during the training of detection models has been demonstrated to yield an average precision that is 11.72 percentage points higher than that achieved through training with the original dataset. In summary, the technical approach proposed in this paper enables accurate and efficient detection and identification of fouling shellfish on marine aquaculture cages. Full article

The dugong (Dugong dugon) is the sole extant species of the genus Dugong within the order Sirenia, and the only strictly herbivorous marine mammal. As one of the oldest marine mammals, it plays a vital role in maintaining marine biodiversity. Inhabiting the shallow waters of the Indian Ocean and western Pacific, its populations and their seagrass habitats continue to decline due to compounded pressures from human activities and climate change. The International Union for Conservation of Nature (IUCN) currently classifies the species as vulnerable to endangered. Dugongs were once widely distributed along China’s southern coast, but sightings have become extremely rare since 2000. Population recovery remains challenging, necessitating urgent actions to enhance protection and restoration of critical habitats—particularly seagrass beds—alongside foundational scientific research. This paper examines the conservation status and threats to China’s dugong population and their habitats, analyzes conservation challenges, and proposes protection strategies (including strengthening protection and management of dugongs and their habitats; exploring population recovery methods; enhancing habitat monitoring; improving population monitoring techniques; and raising public awareness). These protection strategies aim to advance dugong conservation. Full article

Xestoquinone derivatives isolated from marine sponges exhibit a range of bioactivities, including the inhibition of HIF signaling, mitochondrial function, and tumor cell proliferation. Mechanistic investigation suggested that 14-hydroxymethylxestoquinone (1) acts as a protonophore. Although adociaquinones A (5) and B (6) each stimulated cellular oxygen consumption, neither affected mitochondrial membrane potential. Cell-based respiration studies revealed that adociaquinones restored sodium azide-stalled oxygen consumption and ascorbate enhanced this response, suggesting ascorbate-supported redox cycling as a possible mechanism by which adociaquinones suppress HIF and tumor cell proliferation. These xestoquinone derivatives activated cellular stress response pathways that inhibit protein translation by phosphorylating key regulatory proteins (i.e., eIF2α, eIF4E, and eEF2). Further, thiol-reducing agents NAC and DTT attenuated the monosubstituted xestoquinone derivatives’ efficacy to inhibit HIF signaling, suggesting a potential mechanism of action that involves sulfhydryl modification. Full article

Detecting underwater debris is important for monitoring the marine environment but remains challenging due to poor image quality, visual noise, object occlusions, and diverse debris appearances in underwater scenes. This study proposes UDD-YOLO, a novel detection framework that, for the first time, applies a diffusion-based model to underwater image enhancement, introducing a new paradigm for improving perceptual quality in marine vision tasks. Specifically, the proposed framework integrates three key components: (1) a Cold Diffusion module that acts as a pre-processing stage to restore image clarity and contrast by reversing deterministic degradation such as blur and occlusion—without injecting stochastic noise—making it the first diffusion-based enhancement applied to underwater object detection; (2) an AMC2f feature extraction module that combines multi-scale separable convolutions and learnable normalization to improve representation for targets with complex morphology and scale variation; and (3) a Unified-IoU (UIoU) loss function designed to dynamically balance localization learning between high- and low-quality predictions, thereby reducing errors caused by occlusion or boundary ambiguity. Extensive experiments are conducted on the public underwater plastic pollution detection dataset, which includes 15 categories of underwater debris. The proposed method achieves a mAP50 of 81.8%, with 87.3% precision and 75.1% recall, surpassing eleven advanced detection models such as Faster R-CNN, RT-DETR-L, YOLOv8n, and YOLOv12n. Ablation studies verify the function of every module. These findings show that diffusion-driven enhancement, when coupled with feature extraction and localization optimization, offers a promising direction for accurate, robust underwater perception, opening new opportunities for environmental monitoring and autonomous marine systems. Full article

Polysaccharides from marine organisms have been extensively studied and utilized as functional food ingredients due to their excellent immunomodulatory properties. However, the immunomodulatory potential of fermented Ruditapes philippinarum polysaccharide (RPP) has not been systematically explored. This study investigated the effects of RPP on immune function in cyclophosphamide (CTX)-induced immunosuppressed BALB/c mice. These results revealed that RPP alleviated CTX-induced weight loss and restored appetite. Moreover, RPP can promote the morphology and indices of immune organs, as well as increased the number of white blood cells (WBC), red blood cells (RBC), and hemoglobin (Hb). Serum levels of interleukin-6 (IL-6) and immunoglobulin E (IgE) were significantly elevated following RPP treatment. Additionally, RPP improved colonic morphology by upregulating the expression of E-cadherin and ZO-1 and promoting the secretion of secretory IgA (sIgA). These results indicated that RPP exerted an immune protective effect in BALB/c mice and justified its further potential as a bioactive ingredient for functional foods derived from marine shellfish. Full article