Search Results (1,082)

Stutzerimonas, a genus newly separated from the Pseudomonadaceae family in 2022, has attracted considerable attention due to its diverse metabolic capabilities and environmental adaptability. However, the mechanisms underlying its sulfur-oxidizing capacity and survival strategies in extreme environments remain poorly understood. Clarifying potential sulfur-oxidizing microbial groups contributes to a more accurate understanding of energy flow and elemental cycling in hydrothermal ecosystems. In this study, we isolated and identified a sulfur-oxidizing strain, designated 381-2^T, from sediments in the Tianxiu hydrothermal field of the northwest Indian Ocean, and proposed it as a new species of Stutzerimonas. Physiological characterizations demonstrated that strain 381-2^T could oxidize thiosulfate to tetrathionate and encoded the key sulfur oxidation gene tsdA. Cultivation with sulfide minerals showed that strain 381-2^T could influence sulfide mineral weathering through metabolic activities, such as pH regulation, and potentially promote the reprecipitation of metal ions on the microbial surface. Comparative genomic analysis of 322 Stutzerimonas genomes further revealed the widespread presence of the tsdA gene and metal resistance genes, suggesting potential adaptive strategies for survival in hydrothermal environments. This study expands the understanding of Stutzerimonas species and provides insights into their ecological roles in hydrothermal systems. Full article

Canada’s commitment to conserving 30% of its lands and oceans by 2030 is an incredibly ambitious objective requiring immense political and strategic effort. Despite initiatives by federal, provincial, territorial, and Indigenous governments, this target remains distant. This paper identifies key threats faced by protected area (PA) experts to achieve conservation objectives. Major obstacles include recreational overuse, resource extraction, habitat fragmentation, and political–economic pressures. To guide land management and maintain ecological integrity, the study illustrates the value of planning strategies, such as linking land cover with ecosystem dynamics. This relationship provides a pragmatic strategy for the administration of PAs while acknowledging the necessity for a more intricate, ecosystem-oriented approach. Using legal and policy analysis as well as semi-structured interviews with key conservation stakeholders throughout British Columbia (BC), this paper contends that applying ecosystem principles can assist managers of PAs to identify planning opportunities to more effectively reconcile conservation and recreational priorities while supporting climate resilience. Full article

Blue carbon ecosystems are critical biodiversity hotspots facing escalating threats. Coastal and Marine Spatial Planning (CMSP) is a key policy tool for protecting their biodiversity and enhancing ecosystem services, resilience, climate action, and sustainable development. We performed a systematic bibliometric analysis (1981–2025) using the Web of Science Core Collection. The results indicated that global CMSP–blue carbon ecosystems collaborative research exhibits a three-stage evolutionary pattern: the initial phase (2008–2012) of blue carbon concept introduction; the development phase (2013–2018), where research focus shifted to carbon sinks and ecology driven by policy initiatives; and the growth phase (2019–2025), where research focused on precision systematic governance. Research has evolved from baseline ecosystem assessments to policy governance integration, which emerged as a core component of Marine Spatial Planning to advance sustainable development. Research networks exhibit a “center–periphery” pattern. However, the international influence of China’s research output remains limited. Future CMSP collaborative governance will require refining planning frameworks, addressing regional technical adaptation challenges, and establishing a multidimensional policy system to reconcile the effective conservation of blue carbon ecosystems in order to reconcile biodiversity, resilience, and sustainable development. This study maps the CMSP–blue carbon ecosystems research landscape, informing improved climate-friendly marine and coastal spatial planning for enhanced coastal wetland biodiversity and ecological resilience. Full article

Eukaryotic algae are key contributors to biodiversity and ecosystem functioning in aquatic environments. However, understanding their global diversity patterns and community assembly mechanisms remains limited by the lack of high-resolution, highly specific analytical methods. Here, we present the first eukaryotic algae-specific classification database, EukAlgae-T (Eukaryotic Algae Taxonomic database), constructed based on single-copy orthologous genes. The database integrates 50,581 non-redundant marker genes from 479 high-quality genomes and was applied to analyze 939 marine metagenomic samples from the Tara Oceans project. Our results reveal that the genomically represented fraction of the global algal community is dominated by a widely distributed core taxonomic group, comprising 125 of the 230 detected species. Redundancy analysis indicated that community structure is primarily regulated by latitude and iron concentration on a global scale. In contrast, Mantel tests revealed strong regional heterogeneity, with temperature, salinity, and iron concentration acting as universal local drivers, albeit with varying effect sizes and combinations across ocean basins. Co-occurrence network analysis further demonstrated predominantly cooperative interactions among taxa, forming a highly modular and stable network structure, and identified key hub taxa characterized by low abundance but high connectivity. Together, this study provides a dedicated framework for eukaryotic algae metagenomic analysis and demonstrates that algal community assembly is driven by multi-scale environmental filtering: broadly constrained by climate zones and iron limitation at the global scale and regionally reshaped by local oceanographic processes (e.g., thermohaline structure). Cooperative coexistence and niche differentiation among taxa jointly underpin the maintenance of global algal diversity. Full article

Macroalgae are essential components of marine ecosystems, supporting biodiversity, primary productivity, and the functioning of coastal habitats. In the northeast Atlantic Macaronesian archipelagos (Azores, Madeira, Selvagens, Canary Islands, Cabo Verde), they hold significant ecological and economic value and have recently emerged as key indicators of environmental change. This oceanic region faces increasing pressure from multiple stressors, including climate change, invasive species, habitat degradation, and other anthropogenic impacts, driving shifts in coastal ecosystems and the simplification of structurally complex habitats such as marine forests. To assess the current state of knowledge on Macaronesian macroalgae and identify gaps relevant to conservation and management, we conducted a systematic literature review following PRISMA guidelines. Our results show strong but uneven foundational knowledge, with the Azores and Canary Islands accounting for roughly 80% of publications. Research is dominated by fundamental studies in ecology and taxonomy, while applied research (e.g., resource exploitation, aquaculture, toxicology, and climate-change impacts) remains limited. Red algae and a few dominant orders (Ceramiales, Fucales, Dictyotales) are well represented, whereas green algae and less conspicuous taxa are understudied. Future research should expand geographic coverage, broaden taxonomic scope using molecular tools, strengthen applied research, standardize monitoring frameworks, and align scientific output with management needs. Full article

Underwater wireless optical communication (UWOC) has emerged as a key enabler for Internet of Underwater Things (IoUT) and autonomous sensing networks, but its reliability is severely affected by salinity-induced attenuation, scattering, and turbulence. This work presents a high-speed and salinity-resilient UWOC architecture that jointly exploits Polarization Division Multiplexing (PDM) and Multiple-Input Multiple-Output (MIMO) diversity to enhance link capacity and robustness in realistic oceanic conditions. Two 1 Gbps NRZ data channels at 1550 nm were transmitted using continuous-wave lasers and evaluated using a hybrid OptiSystem–MATLAB simulation framework with full channel modeling of absorption, scattering, turbulence, and salinity (32–36 ppt). Results reveal that the proposed PDM-MIMO system achieves more than an order-of-magnitude bit-error-rate (BER) reduction compared with non-MIMO or single-polarization baselines, maintaining acceptable BER levels up to 20 m. Performance degradation with increasing salinity is quantified, and results confirm that combined PDM and spatial diversity effectively mitigate salinity-induced losses. The presented design demonstrates a viable and scalable solution for next-generation underwater sensing and communication networks in coastal and deep-sea ecosystems. Full article

Plastic has transitioned rapidly from a revolutionary material to a global environmental concern, primarily due to mismanagement. Synthetic polymers have quickly gained widespread use due to their versatility, durability, and affordability. However, the properties making plastic indispensable contribute to its permanence in the environment, where it breaks down into microplastics—tiny particles that are typically classified in the size range from 0.1 μm to 5 mm. These particles can now be found in all ecosystems, including the oceans, soil, atmosphere, and within living organisms, raising global concerns about their long-term environmental and health impacts. This review critically examines the current status and potential for identifying, analyzing, and mitigating microplastic pollution. In this paper, we particularly focus on the destructive and non-destructive analytical methods used for microplastic identification and characterization, examining their technical capabilities and limitations, the challenges in maintaining sample integrity, and the reliability of their quantification methods. In addition, the review addresses microplastic removal strategies, from laboratory procedures to real-world applications, examining barriers to implementation and the limited availability of existing solutions. Finally, the review highlights the urgent need for standardized protocols, regulatory frameworks, and interdisciplinary collaboration to address the multifaceted nature of microplastic pollution. Full article

The Eastern Adriatic Sea is biogeographically complex, yet knowledge of its hydromedusae is fragmented across two centuries of uneven sampling and shifting taxonomy. This review integrates historical faunistic records (pre-1950), mid-century programmes (1950–2000), modern quantitative time series (post-2000), and citizen science observations to compile an updated checklist of 98 non-siphonophoran hydrozoan taxa. Records are synthesised across eight sub-regions, although the most continuous research has focused on the Northern Adriatic and the open South Adriatic. The clearest long-term signal is in the Northern Adriatic, where diversity collapsed by >60% from the 1960s to the 1980s, largely through the loss of meroplanktonic taxa with benthic polyp stages under eutrophication-driven hypoxia. Since 2000, oligotrophication coincides with a partial recovery, marked by the re-emergence of meroplankton and episodic intrusions of oceanic holoplankton (including Trachymedusae) linked to circulation regimes (BiOS). For the open South Adriatic, bathymetric distributions and diel vertical migration patterns are synthesised to characterise a persistent offshore core. Taxonomic updates and information on non-indigenous and bloom-forming taxa are provided. Methodological biases and gaps, especially polyp-stage ecology and spatial sampling voids, are highlighted, and routine DNA barcoding is recommended. The checklist provides a baseline for tracking change in a shifting ecosystem. Full article

Polar sea ice is undergoing rapid change, with recent record-low extents in both hemispheres, raising the demand for skillful predictions from days to seasons for navigation, ecosystem management, and climate risk assessment. Accurate sea ice prediction is essential for understanding coupled climate processes, supporting safe polar operations, and informing adaptation strategies. Physics-based numerical models remain the backbone of operational forecasting, but their skill is limited by uncertainties in coupled ocean–ice–atmosphere processes, parameterizations, and sparse observations, especially in the marginal ice zone and during melt seasons. Statistical and empirical models can provide useful baselines for low-dimensional indices or short lead times, yet they often struggle to represent high-dimensional, nonlinear interactions and regime shifts. This review synthesizes recent progress of DL for key sea ice prediction targets, including sea ice concentration/extent, thickness, and motion, and organizes methods into (i) sequential architectures (e.g., LSTM/GRU and temporal Transformers) for temporal dependencies, (ii) image-to-image and vision models (e.g., CNN/U-Net, vision Transformers, and diffusion or GAN-based generators) for spatial structures and downscaling, and (iii) spatiotemporal fusion frameworks that jointly model space–time dynamics. We further summarize hybrid strategies that integrate DL with numerical models through post-processing, emulation, and data assimilation, as well as physics-informed learning that embeds conservation laws or dynamical constraints. Despite rapid advances, challenges remain in generalization under non-stationary climate conditions, dataset shift, and physical consistency (e.g., mass/energy conservation), interpretability, and fair evaluation across regions and lead times. We conclude with practical recommendations for future research, including standardized benchmarks, uncertainty-aware probabilistic forecasting, physics-guided training and neural operators for long-range dynamics, and foundation models that leverage self-supervised pretraining on large-scale Earth observation archives. Full article

With the increasing detection of micro- and nanoplastics (MNPs) in marine environments and the expanding body of related research, their environmental behavior and ecological effects have become central topics in marine environmental science. This review addresses the growing concern over MNP pollution in the marine realm, encompassing their primary sources, spatial accumulation and distribution, environmental transport and transformation dynamics, and ecotoxicological effects on marine organisms and ecosystems, as well as the ecological risks they pose within key habitats such as seagrass beds and coral reefs. We synthesize evidence on the biological impacts of MNPs, including oxidative stress, tissue accumulation, metabolic disturbances, and immune impairment, as well as the heightened risk of pathogen transmission facilitated by the so-called “Plastisphere”. Moreover, we explore the potential implications of MNP exposure on oceanic carbon cycling and net primary productivity. The reviewed literature suggests that MNPs are capable of long-range transport and progressive fragmentation into ultrafine particles, which are readily ingested and retained by a wide array of marine organisms, subsequently inducing toxicological effects and compromising both organismal health and ecological integrity. Such disturbances may undermine critical ecosystem services, including carbon sequestration capacity and food web stability. Finally, based on the current research landscape, we outline future research priorities: improving environmental detection and toxicological evaluation of MNPs, elucidating their long-term effects at the ecosystem scale, and investigating their interactions with co-occurring pollutants under complex, multi-stressor scenarios. These efforts are essential to support science-based assessment and effective management strategies for marine MNP pollution. Full article

Peatlands play a critical role in global and regional climate regulation by functioning as long-term carbon sinks, regulating hydrology, and modulating land–atmosphere energy exchange. Intact peat ecosystems store large amounts of organic carbon and stabilize local climate through high water retention and evapotranspiration, whereas peatland degradation disrupts these functions and can transform peatlands into significant sources of greenhouse gas emissions and climate extremes such as drought and fire. Indonesia contains approximately 13.6–40.5 Gt of carbon, around 40% of which is stored on the island of Sumatra. However, tropical peatlands in this region are highly vulnerable to climate anomalies and land-use change. This study investigates the impacts of major climate anomalies—specifically El Niño and positive Indian Ocean Dipole (pIOD) events in 1997/1998, 2015/2016, and 2019—on peatland cover change across South Sumatra, Jambi, Riau, and the Riau Islands. Landsat 5 Thematic Mapper and Landsat 8 Operational Land Imager/Thermal Infrared Sensor imagery were analyzed using a Random Forest machine learning classification approach. Climate anomaly periods were identified using El Niño-Southern Oscillation (ENSO) and IOD indices from the National Oceanic and Atmospheric Administration. To enhance classification accuracy and detect vegetation and hydrological stress, spectral indices including the Normalized Difference Vegetation Index (NDVI), Modified Soil Adjusted Vegetation Index (MSAVI), Normalized Difference Water Index (NDWI), and Normalized Difference Drought Index (NDDI) were integrated. The results show classification accuracies of 89–92%, with kappa values of 0.85–0.90. The 2015/2016 El Niño caused the most severe peatland degradation (>51%), followed by the 1997/1998 El Niño (23–38%), while impacts from the 2019 pIOD were comparatively limited. These findings emphasize the importance of peatlands in climate regulation and highlight the need for climate-informed monitoring and management strategies to mitigate peatland degradation and associated climate risks. Full article

Understanding ocean temperature structure and its spatiotemporal variability is essential for studying ocean circulation, climate, and marine ecosystems. While previous approaches using observations and numerical models have advanced our understanding, they face limitations such as sparse data coverage and computational bias. To address these issues, we developed an ensemble of data-driven neural network models trained with in situ vertical profiles and daily remote sensing inputs. Unlike previous studies that were limited to open-ocean regions, our model explicitly included coastal areas with complex bathymetry. The model was applied to the East/Japan Sea and reconstructed 31 years (1993–2023) of daily three-dimensional ocean temperature fields at 13 standard depths. The predictions were validated against observations, showing RMSE < 1.33 °C and bias < 0.10 °C. Comparisons with previous studies confirmed the model’s ability to capture short- to mid-term temperature variations. This data-driven approach demonstrates a robust alternative to traditional methods and offers an applicable and reliable tool for understanding long-term ocean variability in marginal seas. Full article

Mangrove ecosystems along the Indian Ocean coast show great biodiversity, adapting to harsh environmental conditions of high salinity and higher organic matter, and they are a host for a range of microbial communities with special features that produce unique secondary metabolites. Of this, mangrove-associated endophytic fungi, the second largest ecological group of marine fungi, show the greater potential, being a diverse pool for discovering novel bio-actives with pharmacological and biotechnological interest. This review summarizes the research findings on structural diversity and the associated pharmacological activities of secondary metabolites produced by mangrove-associated fungi along the Indian Ocean coast reported over the period of 2002–2025, based on the literature retrieved from Google Scholar. The total of 302 secondary metabolites is presented mainly from classes of polyketides (208), alkaloids (34), and terpenoids (60). Interestingly, 164 compounds were identified, as first reported in those publications. These compounds have been reported to show diverse biological activities, and the most prominent activities are cytotoxic, antibacterial, antifungal, antioxidant, enzyme inhibitory, and anti-inflammatory effects. The structural novelty and pharmacological activities of these metabolites highlight the importance of mangrove fungi as promising sources for new drug discovery and advancing industrial biotechnology. Therefore, this review highlights the insight into the possible application of these chemical compounds in the future drug industry, as well as in biotechnology for advancing human well-being. Furthermore, though significant progress has been made in exploring the fungi community from mangroves of the African and Middle Eastern coasts, the Indian coast mangrove fungi are yet to be explored more for novel discoveries. Full article

We argue that a multidisciplinary approach is essential to identify deoxygenation impacts on marine ecosystems and fisheries, bridging across the traditionally separate fields of oceanography and economics. Oceanography reveals physical and chemical drivers of deoxygenation, and assesses potential biological impacts based on the physiological and ecological characteristics of organisms and communities. Economics identifies the consequences of human activities associated with the utilization of the changing ocean, particularly in relation to deoxygenation. Economic data, models and analysis can contribute to determining the future directions toward achieving a healthy ocean in the context of deoxygenation. However, differing perspectives on the value of the ocean may lead to conflicts between short-term economic gains and long-term sustainability. Uncertainties in fish populations and deoxygenation modeling add complexity. Despite the difficulties involved, the interdisciplinary view of economics and oceanography offers a more comprehensive understanding of the complexities of ocean deoxygenation and its impacts on both the ocean and people. In order to address the challenges posed by deoxygenation and its impacts, and to develop mitigation and adaptation strategies, it is essential to establish a strong collaboration between experts of oceanography and fisheries economics. Full article