Search Results (730)

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

As an important component of waters constituent that affects ocean color and the underwater ecological environment, the accurate assessment of Chromophoric Dissolved Organic Matter (CDOM) is crucial for observing the continuous changes in the marine ecosystem. However, remote sensing estimation of CDOM remains challenging for both coastal and oceanic waters due to its weak optical signals and complex optical conditions. Therefore, the development of efficient, practical, and robust models for estimating the CDOM absorption coefficient in both coastal and oceanic waters remains an active research focus. This study presents a novel algorithm (denoted as DQAAG) that incorporates ultraviolet bands into the inversion model. The design leverages the distinct spectral absorption characteristics of phytoplankton versus detrital particles in the ultraviolet (UV) region, enabling improved discrimination of water color parameters. Furthermore, the algorithm replaces empirical formulas commonly used in semi-analytical approaches with an artificial intelligence model (deep learning) to achieve enhanced inversion accuracy. Using IOCCG hyperspectral simulation data and NOMAD dataset to evaluates Shanmugam (2011) (S2011), Aurin et al. (2018) (A2018), Zhu et al. (2011) (QAA-CDOM), DQAAG, the results indicate that the a_g(443) derived from the DQAAG exhibit good agreement with the validation data, with root mean square deviation (RMSD) < 0.3 m⁻¹, mean absolute relative difference (MARD) < 0.30, mean bias (bias) < 0.028 m⁻¹, coefficient of determination (R²) > 0.78. The DQAAG algorithm was applied to SeaWiFS remote sensing data, and validation was performed through match-up analysis with the NOMAD dataset. The results show the RMSD = 0.14 m⁻¹, MARD = 0.39, and R² = 0.62. Through a sensitivity analysis of the algorithm, the study reveals that R_rs(670) and R_rs(380) exhibit more significant characteristics. These results demonstrate that UV bands play a crucial role in enhancing the retrieval accuracy of ocean color parameters. In addition, DQAAG, which integrates semi-analytical algorithms with artificial intelligence, presents an encouraging approach for processing ocean color imagery to retrieve a_g(443). Full article

Aquatic environments have been a critical source of nutrition for millennia, with wild fisheries supplying protein and nutrients to populations worldwide. A notable shift has occurred in recent decades with the expansion of aquaculture, now representing a fast-growing sector in food production. Aquaculture plays a key role in mitigating the depletion of wild fish stocks and addressing issues related to overfishing. Despite its potential benefits, the sustainability of both wild and farmed aquatic food systems is challenged by anthropogenic pollution. Contaminants from agricultural runoff, industrial discharges, and domestic effluents enter freshwater systems and eventually reach marine environments, where they may be transported globally through ocean currents. Maintaining water quality is paramount to food safety, environmental integrity, and long-term food security. In addition to conventional seafood products such as fish and shellfish, foods such as those derived from microalgae are gaining attention in Western markets for their high nutritional value and potential functional properties. These organisms have been consumed in Asia for generations and are now being explored as sustainable foods and ingredients as an alternative source of protein. Contaminants in aquatic food products include residues of agrochemicals, persistent organic pollutants (POPs) such as dioxins, polychlorinated biphenyls (PCBs), and per- and polyfluoroalkyl substances (PFASs), as well as brominated flame retardants and heavy metals. Public and scientific attention has intensified around plastic pollution, particularly microplastics and nanoplastics, which are increasingly detected in aquatic organisms and are the subject of ongoing toxicological and ecological risk assessments. While the presence of these hazards necessitates robust risk assessment and regulatory oversight, it is important to balance these concerns against the health benefits of aquatic foods, which are rich in omega-3 fatty acids, high-quality proteins, vitamins, and trace elements. Furthermore, beyond direct human health implications, the environmental impact of pollutant sources must be addressed through integrated management approaches to ensure the long-term sustainability of aquatic ecosystems and the food systems they support. This review covers regulatory frameworks, risk assessments, and management issues relating to aquatic environments, including the impact of climate change. It aims to serve as a comprehensive resource for researchers, policymakers, food businesses who harvest food from aquatic systems and other stakeholders. Full article

Microplastics (MPs)—synthetic polymer particles less than 5 mm in size—have emerged as ubiquitous contaminants in terrestrial and aquatic environments worldwide, raising concerns about their ecological and human health impacts. While research has predominantly focused on urban and marine settings, evidence shows that rural ecosystems are also affected, challenging assumptions of pristine conditions outside cities and coasts. This review synthesizes current knowledge on the presence, pathways, and impacts of MPs in rural environments, highlighting complex contamination dynamics driven by both local sources (agricultural plastics, domestic waste, rural wastewater, and road runoff) and regional processes (atmospheric deposition, hydrological transport, and sediment transfer). Key findings highlight that rural lakes, streams, soils, and groundwater systems are active sinks and secondary sources of diverse MPs, predominantly polyethylene (PE), polypropylene (PP), and polyethylene terephthalate (PET) in fibrous and fragmented forms. These particles vary in size, density, and color, influencing their transport, persistence, and bioavailability. Ecological effects include bioaccumulation in freshwater species, soil degradation, and potential food chain transfer, while human exposure risks stem from contaminated groundwater, air, and locally produced food. Despite these growing threats, rural systems remain underrepresented in monitoring and policy frameworks. The article calls for context-specific mitigation strategies, enhanced wastewater treatment, rural waste management reforms, and integrated microplastics surveillance across environmental compartments. Full article

From an ecological perspective, sustainable lighting in urban marine areas requires striking a balance between meeting human needs and protecting marine ecosystems from the harmful effects of disrupting natural light regimes. While managing artificial lighting is crucial, we argue that preventing obstructions to light penetration into the water is as important, as many marine organisms depend on the euphotic zone. This study intends to review the key factors for the implementation of wildlife-friendly lighting design in the urban marine environment, as the subject is explored in ecological studies but scarcely discussed in urban studies. An integrative literature review and cases are employed to synthesise evidence about changes to the light regime in urban marine areas from four perspectives: light reach, intensity, spectrum, and duration. The cases present measures implemented to benefit marine species affected by alterations to the light regime following urbanisation in a way that they could still thrive in a modified built environment. In discussion, it is acknowledged that achieving sustainable lighting in urban marine areas is a multifaceted challenge involving concurrent influencing factors, including a shared agency between humans and non-humans, which may require comprehensive lighting designs that are tailored to specific goals and target species. 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

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

This study examines the occurrence of bacteria resistant to antibiotics and heavy metals in Terra Nova Bay, a coastal area of the Ross Sea in Antarctica that is increasingly recognised as vulnerable to human influence. During the 37th Italian Antarctic Expedition (2021–2022), researchers collected seawater, sediment, and fish samples from the notothenioid species Trematomus bernacchii to evaluate microbial resistance in an environment once considered largely pristine. Fifty heterotrophic bacterial isolates were obtained and tested against twenty-eight antibiotics, revealing a notable presence of multidrug resistance. These multidrug-resistant isolates were then assessed for their tolerance to eight heavy metal salts to understand whether resistance traits extended beyond antimicrobials. Twelve isolates showing resistance to both antibiotics and metals were selected for further genetic screening, targeting key resistance genes linked to tetracycline, vancomycin, sulphonamides, and other antimicrobial classes. The detection of multiple resistance genes in genera such as Pseudomonas, Pseudoalteromonas, and Psychrobacter indicates that both natural selective pressures and local, human-related contamination may be shaping resistance patterns in this region. Overall, the study demonstrates that even remote Antarctic marine ecosystems can host bacteria with complex resistance profiles. While these ecosystems are largely isolated, human activities such as scientific research, tourism, and the introduction of pollutants may contribute to the dissemination of antibiotic resistance genes, raising important ecological and potential public health considerations regarding the spread of resistance in polar environments. Full article

The Veracruz Reef System National Park (VRSNP), located in the central Gulf of Mexico, is one of the country’s most ecologically and economically significant coral systems. Despite its high biodiversity and ecosystem functionality, it is affected by anthropogenic inputs such as fluvial discharges, urban effluents, and port and tourism activities that contribute organic and bacteriological loads. This study aimed to identify the presence of Enterococcus spp. and Vibrio spp. during three climatic seasons—dry, rainy, and north winds—at two water column depths (surface and bottom) across three reefs (Enmedio, Chopas, and Gallega) within the VRSNP during the 2022 annual cycle. Samples were analyzed according to national and international standards. Results showed that Vibrio spp. were influenced mainly by temporal factors, with higher values during north winds and the dry season (>1100 MPN/100 mL); otherwise, rainy conditions reported the lowest load (184.89 ± 15.00 MPN/100 mL). While Enterococcus spp. exhibited greater spatial influence, particularly in surface waters, Enmedio Reef recorded the highest load (478.34 ± 37.28 CFU/100 mL); in addition, Chopas Reef reported the lowest at the bottom (12.43 ± 1.26 CFU/100 mL). The findings highlight the need to strengthen microbiological monitoring protocols in marine coastal ecosystems to assess water quality, public health risks, and the ecological integrity of coral reef environments, as well as the implementation of molecular identification techniques. Full article

With the growing global reliance on marine resources, issues pertaining to the marine environment and the Sustainable Development Goals (SDGs)-integrated development of the marine economy have gained worldwide attention. This study employs the synthetic control method (SCM) and difference-in-differences (DID) approach to assess the impact of three heterogeneous types of marine environmental regulations—market incentives, command-and-control, and public participation—on the SDGs-integrated development of the marine economy. Special focus is placed on the detailed mechanisms through which these regulatory approaches influence five key dimensions of the SDGs-integrated development of the marine economy. Overall, the results show that market incentive regulation has a significant positive effect on the SDGs-integrated development of the marine economy. In contrast, command-and-control and public participation regulations demonstrate varying degrees of inhibitory influence. Examining the five dimensions of SDGs-integrated development, innovation-driven development, industrial coordination, green construction, open cooperation, and the sharing of livelihoods, market incentive regulation promotes innovation-driven and open cooperation dimensions while inhibiting industrial coordination, green construction, and the sharing of livelihoods. command-and-control regulation positively promotes people’s sharing of livelihoods but negatively impacts the other four dimensions, with the strongest inhibitory effect on the innovation-driven dimension. Public participation regulations inhibit innovation-driven development and the sharing of livelihoods, with the most pronounced suppression observed in innovation-driven development. Conversely, they promote industrial coordination, green construction, and open cooperation. Based on these findings, this paper proposes a series of policy recommendations aimed at achieving coordinated integration between marine ecological governance and SDGs-integrated development of the marine economy. Full article

The trophic status of coastal environments is largely controlled by nutrient inputs, particularly nitrogen and phosphorus, whose excess may lead to eutrophication. The northern Adriatic Sea has historically been affected by these processes, with notable impacts on water quality. This study analyses a time series (2015–2024) collected at six offshore sites in the Gulf of Trieste within the Marine Strategy Framework Directive (MSFD) Descriptor 5. Dissolved Inorganic Nitrogen (DIN) showed marked spatial variability, with 19.9% of samples exceeding the threshold of 6.85 µM. Phosphate concentrations were low (mean 0.17 µM), indicating strong P-limitation (mean N:P ratio = 277). Chlorophyll a concentrations (mean 0.9 ± 0.1 µg L⁻¹) reflected oligotrophic conditions, although 17% of samples exceeded 1.5 µg L⁻¹. Time-series analyses revealed a significant warming trend (+0.1 °C yr⁻¹; p = 0.022) and a significant decrease in chlorophyll a (p = 0.038), while no significant trends were observed for nutrients, dissolved oxygen or TRIX. TRIX values (0.8–6.9) indicated overall good to high ecological status. A trophic–hydrological gradient highlighted the positive influence of river inputs and precipitation on nutrient availability and trophic conditions. These results provide a solid quantitative baseline for MSFD assessments and underscore the role of hydrological and meteorological forcing in shaping trophic variability in the Gulf of Trieste. Full article

With the trend of internationalization, maritime traffic density has gradually increased. Since 2002, the International Maritime Organization (IMO) has required various types of vessels to be equipped with the Automatic Identification System (AIS). Through AIS static and dynamic data, more complete navigational information of vessels can be obtained. As the Port of Kaohsiung is currently transitioning into a smart port, this study focuses on inbound and outbound vessels of the Second Port of Kaohsiung. It considers both the safety monitoring of the smart port and environmental security, integrating a big data database to provide early warnings for abnormal navigation conditions. This study builds an integrated database based on vessel AIS data, conducts AIS big data analysis to extract useful information, and establishes a random forest model to predict whether a vessel’s course and speed during port navigation deviate from normal patterns, thereby achieving the goal of early warning. This study also helps reduce the risk of collisions caused by abnormal vessel operations and thus prevents marine pollution in the port area due to oil spills or hazardous substance leakage. Through real-time monitoring and early warning of navigation behavior, it not only enhances navigation safety but also serves as the first line of defense against marine pollution, contributing significantly to the protection of the port’s ecological environment and the promotion of sustainable development. Full article

Many studies have been conducted on wave and sediment movement with submerged dikes. However, the effect of a submerged dike’s height and orientation on hydrodynamics has not been thoroughly examined from the perspective of the marine ecology impact. This paper employs a two-dimensional numerical model to investigate effects of submerged dike height and orientation on flow, specifically flow velocity and cross-dike flux. The findings indicate that the most significant velocity variation occurs at a distance of approximately one-fifth of the dike length (0.2 L) from the dike head, when the flow is perpendicular to the dike and parallel to the coastline. And this area as the submerged dike’s protection zone will have the least impact on the surrounding environment. The change pattern of the flow velocity with the distance apart from the submerged dike varies for different submerged dike heights. A submerged dike height of 0.7 times the water depth (0.7 H) is a dividing value. Additionally, as the orientation angle increases, the cross-dike flux rises. From the perspective of the impact on the marine ecological environment, the design angle of the submerged dike should be as small as possible. The findings establish a theoretical hydrodynamic basis that may support future integrated studies on coastal zone management. Full article

Bacterial biofilms on different types of microplastics in aquatic environments have become an increasing ecological and public health concern. In this context, this study investigated biofilm formation on virgin and aged microplastics under marine conditions. Serratia marcescens biofilm formation was observed on both virgin and aged polyethylene particles after 7 days, with no significant changes by day 14. Concerning polypropylene microplastics, biofilms developed on aged particles but were not detectable on virgin particles, likely due to interference from the polypropylene red color matching S. marcescens cells. In contrast, expanded polystyrene spheres showed an initial biofilm formation that dissipated by day 14, potentially due to toxic residues from photooxidation, including potential styrene monomers and other chemical additives, inhibiting biofilm persistence. These findings indicate differences in biofilm formation across microplastics types, which may influence microplastic buoyancy and ecological impacts. Thus, microplastic color and additives should be considered in future studies on microplastics biofilm formation and biofouling. Full article

This study aimed to explore the trade-offs between regional economic activity and environmental policy to explore economic approaches for reducing and managing pollutant discharge while maintaining a balance between socioeconomic activities and the marine environment. A linear programming simulation was conducted to model the interactions between socioeconomic activities, pollutant emissions, and reduction policies in the Omura Bay watershed. The model was designed to maximize Gross Regional Product (GRP), using inflow pollutant loads as a constraint. The simulation showed that a 12.7% reduction in 2015 pollutant loads is feasible under total load control. However, this level of reduction would cause a 14% decrease in watershed GRP. Further analysis revealed that reductions beyond 12.4% would significantly lower GRP and increase the cost of mitigation, making a 12.3% reduction the most realistic upper limit. The estimated cost of implementing countermeasures to manage pollutant inflow was JPY 6.7 billion, which would translate to a JPY 37.6 billion reduction in the cost to maintain current conditions and a JPY 26.7 billion reduction in the maximum reduction scenario (12.3%) with minimal economic impact. This analysis highlights the tradeoff between environmental protection and economic performance. A key innovation is the proposal of a “proper nutrient management” scenario, moving beyond uniform reductions to assess region-specific targets that consider ecological needs, such as those of the fishery industry. This approach emphasizes the importance of setting realistic and ecologically balanced reduction targets. Full article