Search Results (1,138)

Coastal wetlands are important sinks for heavy metals, yet the linkage between vertical redistribution, quantitative source contributions, and ecological–health risk drivers remain insufficiently understood. This study collected the stratified sediment samples from three depth intervals (0–20, 20–40, and 40–60 cm) from 28 representative sites in the coastal wetlands of western Bohai Bay, and evaluated the spatial distribution, vertical variation, pollution status, potential sources, and ecological–human health risks of eight heavy metals (Cr, Ni, Cu, Zn, As, Cd, Hg, and Pb). The mean concentrations were below the Class I limits of the Marine Sediment Quality Standard. Most metals were close to or slightly below regional background values, whereas Cu and As showed mild enrichment and Cr was higher than values reported for Bohai Bay and Hangzhou Bay. Vertical profiles were generally homogeneous, with weak enrichment of specific metals, probably due to sediment resuspension, tidal disturbance, and bioturbation. Pollution assessment based on the geoaccumulation index (Igeo), Nemerow pollution index (P_N), and pollution load index (PLI) consistently indicated low contamination levels, with Hg and Pb as the main contributors to the regional pollution load. Source apportionment indicated that heavy metals were jointly influenced by lithogenic background (38.9%), atmospheric deposition (31.1%), and local anthropogenic activities (30.0%). Ecological risk assessment showed that the integrated risk index (RI) remained within the low-risk category, although Hg consistently fell within the moderate-risk range and Cd approached the moderate-risk threshold. Health risk assessment showed that both non-carcinogenic and carcinogenic risks were within acceptable limits for all receptor groups. Children had higher risks in core residential areas, whereas adults showed higher risks in non-core industrial–agricultural zones because of increased exposure frequency. The source–risk analysis indicates that non-carcinogenic risk is mainly associated with background-derived Cr, whereas carcinogenic risk is primarily linked to anthropogenic As inputs. These findings indicate that source contributions and risk contributions are not necessarily consistent, highlighting the need for source-oriented risk management in industrialized coastal wetlands. Full article

The Guangdong–Hong Kong–Macao Greater Bay Area (GBA) is a densely populated, highly connected coastal urban region that is exposed to typhoons, extreme rainfall, flooding, storm surges, heat-related risks, and public health emergencies. Existing studies have clarified many aspects of hazard exposure and spatial vulnerability, but evidence on how residents receive warnings, interpret risks, prepare, evacuate, and contribute to community resilience remains dispersed across disciplines and jurisdictions. This study maps the intellectual structure and thematic evolution of research on residents’ responses to urban disaster risks in the GBA. Following a PRISMA 2020-aligned identification and screening process, 144 records from the Web of Science Core Collection were manually screened. Bibliometric analysis, keyword co-occurrence analysis, a region–hazard matrix, and a BERTopic-inspired topic modelling procedure were then used to identify publication trends, disciplinary sources, spatial hazard patterns, and latent themes. The results show accelerated growth after 2020 and identify six interrelated themes: risk perception and preparedness; evacuation and shelter accessibility; urban flooding vulnerability; typhoon, storm surge, and coastal community risk; community resilience and climate adaptation governance; and health emergency response and psychosocial resilience. The review synthesises these findings into a heuristic framework linking risk information, cognitive appraisal, response action, and community resilience. The GBA is treated as an analytically informative, rather than statistically representative, case of a high-density, coastal, and multi-jurisdictional urban region. The findings suggest that resident-centred resilience planning should connect trusted and actionable warnings with inclusive digital communication, accessible protective resources, and cross-boundary coordination for compound hazards. Full article

Although recent studies have significantly improved our understanding of submerged landscapes along the karstified eastern Adriatic coast, many aspects of their evolution and response to post-glacial relative sea-level rise remain poorly understood. Thus, the present study offers new insights into the Late Quaternary paleoenvironmental history of Pirovac Bay, a submerged coastal karst basin in the central Adriatic, by integrating high-resolution seismic data with chronologically constrained sediment cores. The results revealed the existence of two morphologically distinct karst depressions that provided accommodation space for the formation of diverse depositional environments. The Late Glacial and Holocene sedimentary succession documents an evolution from subaerial and fluvially influenced settings to lacustrine and ultimately fully marine environmental conditions. The identified fluvio-karst valley highlights the largely unexplored role of fluvio-karst processes in the development of coastal karst basins, while the discovered Pirovac paleolake is the youngest submerged Holocene lake known along the eastern Adriatic coast. The present-day embayment appears to be characterized by erosional processes and active submarine groundwater discharge, reflecting highly dynamic hydrological conditions. These findings contribute to a better understanding of the interactions between karstification, sea-level rise, sedimentary processes, and groundwater dynamics in coastal karst basins. They also provide an important framework for future paleoenvironmental and hydrogeological investigations along the eastern Adriatic coast. Full article

Suspended sediment concentration (SSC) is a critical proxy for coastal water quality, geomorphological evolution, and biogeochemical cycles. In shallow macro-tidal embayments like Sanmen Bay (SMB), China, surface SSC exhibits highly dynamic spatiotemporal variations driven by intense, multi-scale tidal forcing. Using Sentinel-2 MSI imagery processed with the ACOLITE Dark Spectrum Fitting (DSF) algorithm, this study reconstructs the spatial distribution of surface SSC across the embayment. We then introduce the normalized Suspended Sediment Concentration Asymmetry Index ($A_{ssc}$) to quantitatively diagnose asymmetrical sediment responses across spring–neap and flood–ebb cycles. The results reveal a spatially divergent, dual-control mechanism governing sediment transport across the embayment’s hydro-geomorphic gradients. Quantitative trend-surface fittings and stratified regressions demonstrate that net sediment transport in deep bedrock channels is primarily governed by tidal pumping. Conversely, sediment dynamics on intertidal mudflats and shallow subtidal shoals are modulated by geomorphic resistance, exhibiting high morphodynamic sensitivity to minute water depth variations. By bridging process-based estuarine tidal theory with discrete satellite observations, this reproducible framework transforms multi-temporal remote sensing snapshots into spatially continuous diagnostics, providing a practical decision-support paradigm for coastal engineering and ecosystem management in dynamically analogous macro-tidal environments. Full article

In temperate coastal waters, phytoplankton communities often follow a classical seasonal pattern, with diatoms dominating in spring and dinoflagellates becoming more prominent during summer. However, spring-to-summer phytoplankton community reorganization in eutrophic Liaodong Bay remains poorly characterized. Here, we examined seasonal changes in phytoplankton communities and environmental conditions in Liaodong Bay in spring and summer 2025. The phytoplankton community underwent a marked spring-to-summer reorganization that differed from the classical seasonal pattern. In spring, dinoflagellates accounted for 63.51% of total community abundance, with the heterotrophic dinoflagellate N. scintillans comprising 99.56% of this fraction. By contrast, diatoms comprised 91.02% of the summer community, with Coscinodiscus granii, Skeletonema costatum, and other diatom taxa sharing dominance. This reorganization coincided with a seasonal shift in phosphorus regime and nutrient stoichiometry, from low dissolved inorganic phosphorus (DIP; 0.12 μmol P L⁻¹), dominance of dissolved organic phosphorus (DOP; 0.28 μmol P L⁻¹) and high N:P in spring to higher DIP (0.66 μmol P L⁻¹), lower DOP (0.18 μmol P L⁻¹), lower N:P, and higher Si:N in summer. Correlation and redundancy analyses indicated that the spring N. scintillans-dominated assemblage was broadly aligned with DOP-rich and high-N:P conditions, whereas summer-dominant diatoms were broadly aligned with DIP, dissolved silicate (DSi), and Si:N gradients, although not all bivariate relationships were significant. These patterns suggest that potential relative inorganic phosphorus deficiency in spring may have been less favorable for diatom dominance, whereas higher DIP, lower N:P, and higher Si:N in summer were consistent with a resource regime more favorable for multi-diatom expansion. Overall, the phytoplankton community in Liaodong Bay exhibited a non-classical seasonal reorganization from a spring N. scintillans-dominated assemblage, rather than a conventional autotrophic dinoflagellate-dominated stage, to summer multi-diatom co-dominance, coinciding with shifts in phosphorus regime and nutrient stoichiometry. Full article

Multiple environmental stressors can directly or indirectly affect zooplankton community structure in marine coastal waters. However, quantifying the relative importance of eutrophication-mediated pathways remains challenging. In this study, we surveyed zooplankton, phytoplankton, and water conditions at 24 stations in Qinzhou Bay during spring and used correlation analysis and structural equation modelling (SEM) to examine the association between eutrophication and zooplankton biomass. The results showed that zooplankton biomass increased from the Inner Bay to the Outer Bay; whereas, zooplankton evenness decreased. Biomass was significantly negatively correlated with both the eutrophication index and zooplankton evenness; a single small copepod numerically dominated the assemblage, so high biomass and low evenness co-occurred as expressions of dominance. The SEM showed an acceptable fit and linked eutrophication to lower zooplankton biomass mainly through heavy-metal enrichment, community dominance (low evenness), and reduced phytoplankton density. The total association between eutrophication and biomass was −0.40, primarily indirect rather than through a significant direct path (−0.13, p = 0.51), with heavy-metal enrichment and community dominance (low evenness) as the main statistical mediators. Because the data come from a single spring survey of 24 stations, these path coefficients should be interpreted as correlational associations requiring multi-season confirmation. Full article

Southern Australia supports a high diversity of fishes in the family Syngnathidae, which is recognised as globally threatened, facing threats from coastal development, over-exploitation and bycatch. In southwestern Australia, Cockburn Sound houses a large industrial port and naval defence assets with plans to substantially expand the port facilities but also sits within a recognised syngnathid ‘hotspot’. Using a broad array of data sources, including historical museum vouchers, published records, historical and contemporary observations from notebooks and diving surveys, historical and contemporary trawl surveys, citizen science observations and environmental DNA, we compiled 4839 records of syngnathid fishes from the embayment. Twenty-one species of seadragons, seahorses or pipefishes were confirmed from an area of around 200 km², representing a high diversity by area on a global scale. This remarkable diversity exists despite the bay being a highly modified system. Many species are likely to face conservation concerns within the bay, but others may benefit from the addition of artificial structures. There is clearly a need to protect the diversity and mitigate detrimental impacts from development and ongoing infrastructure operations, including direct and indirect interaction, habitat loss, water quality, turbidity, noise and introduced pests. Full article

The paper addresses the intersection between modern built heritage preservation and Climate-Aided Design (CADe) processes in fragile coastal Mediterranean contexts. The study focuses on the city of Beirut in Lebanon, part of the Eastern Mediterranean and Middle East (EMME) region and considered a climate change hotspot facing extreme challenges. Rapid urbanization and socio-political instability, especially during the twentieth century, have undermined the city’s ability to mitigate and adapt to future climate change scenarios. Moreover, Beirut’s modern built heritage faces a constant threat of demolition due to the absence of protective legislation, compounded by aggressive real-estate development ambitions. The hypothesis is that the integration of climatic data and regenerative design with modern cultural heritage classification frameworks can aid the preservation process, drive a more adaptive and inclusive approach to urban regeneration, and inform legislative integration of climate adaptation in conservation frameworks. To test this hypothesis, a multi-scalar case-study-based methodology is adopted using a combination of digital tools to assess and analyze the current and future impacts of climate change on two main case studies. First, the St. George Hotel & Bay, one of the first reinforced concrete recreational buildings in the city, was built during the French Mandate (1920–1946) and is vulnerable to sea-level rise, flooding, and demolition. Second, the Beirut City Center “The Egg”, a Brutalist structure built during Beirut’s modernist “golden era”, which is prone to structural deterioration and demolition. The main objective is to highlight 20th-century built heritage as part of Beirut’s spatial narrative worthy of conservation and rehabilitation by analyzing their capability to adapt to, mitigate, or benefit from future environmental risk. Ultimately, the study explores their potential to catalyze climate-resilient urban regeneration practices in the city. Results show that the integration of current and future forecast environmental analyses informed early preservation and intervention decision-making stages to position 20th-century modern built heritage as an asset to climate action in addition to being a socio-cultural and economic asset. Full article

Freshwater scarcity and soil salinization limit coastal agriculture, and brackish water irrigation may help alleviate regional water shortages. This study examined the effects of irrigation water salinity on water–salt dynamics and ion distribution in coastal saline soil from Laizhou Bay. Repacked soil column experiments were conducted using a freshwater control and brackish water treatments with TDS levels of 1, 3, and 5 g L⁻¹. Soil water content and electrical conductivity were monitored at 1 min intervals at five depths, and pore water ion composition was analyzed after infiltration. Higher salinity was associated with reduced cumulative infiltration and infiltration rates, delayed wetting front migration, and longer infiltration durations. Freshwater cumulative infiltration reached 11.94 L, whereas the 3 and 5 g L⁻¹ treatments decreased final cumulative infiltration by more than 11%. Soil EC increased with salinity, with higher values occurring mainly in the middle and lower soil layers. Na⁺ and Cl⁻ were the dominant ions contributing to salinity risk and moved downward with the wetting front. Low-salinity brackish water caused less short-term infiltration inhibition and salt accumulation risk than higher-salinity water under laboratory column conditions. However, field validation, crop response evaluation, economic feasibility assessment, and long-term salt balance analysis are required before practical irrigation recommendations can be made. Full article

The Guangdong–Hong Kong–Macao Greater Bay Area (GBA) comprises the two Special Administrative Regions of Hong Kong and Macao, and the nine municipalities of Guangzhou, Shenzhen, Zhuhai, Foshan, Huizhou, Dongguan, Zhongshan, Jiangmen and Zhaoqing in Guangdong Province. The GBA serves as China’s strategic maritime hub and a core engine for marine economic development. However, existing research has underexplored the structural connectivity and topological resilience of its port network from the perspective of a maritime corridor within the GBA. Therefore, using port network data from 2022 to 2023, this study identifies the core topological structure of the GBA maritime corridor and examines how resilience evolves under stochastic connection disruptions. The results show that the GBA maritime corridor exhibits an asymmetric cross-shaped backbone structure that connects domestic coastal ports with international markets (Southeast Asia, Japan, and South Korea). The network density of the GBA port system reaches 0.41258, indicating substantial connectivity that supports efficient regional and global logistics circulation. Regarding resilience level, the probability of connection disruption is the key factor that significantly affects the stability and anti-interference ability of the GBA maritime network. These findings clarify the backbone framework of the maritime corridor for marine economic development, thereby providing theoretical support for strengthening the safety and stability of the GBA maritime transport system. Full article

Microplastic (MP) pollution in marine ecosystems is a matter of concern worldwide, as their ingestion and accumulation in marine fauna pose a significant health risk associated with MP pollution. This detailed study is the first of its kind in the Chandipur coastal waters, Bay of Bengal to comprehensively evaluate MP pollution, and associated pollution load in commonly consumed edible fish and shrimp species. Samples of Harpadon sp., Setipinna taty, Coilia dussumieri, Johnius belangerii, Pampus sp., Arius arius, and Penaeus monodon were collected from Chandipur, Odisha, East coast of India and examined using wet peroxide oxidation, followed by FTIR spectroscopy. A relatively higher concentration of MPs was observed in the muscle tissues (4628 ± 11,702 particles/g of tissue) compared to the gastrointestinal tract (GIT) (4296 ± 9687 particles/g of tissue). The abundance of MPs was maximum in Coilia dussumieri and minimum in Arius arius. Comparatively higher retention of MPs (11,309 ± 15,448 particles/g of tissue) was obtained in the monsoon season than in the pre- and post-monsoon. Microscopic examination revealed the presence of mostly fiber- and fragment-type MPs, in addition to black fibers. The commonly encountered size class was 1–50 µm with 63.4%. FTIR analysis revealed eighteen different types of MPs and polyvinyl chloride (PVC), polyethylene terephthalate (PET), and cellulose acetate (CA) with occurrence percentage between 91.6 and 100%, whereas polyamide (PA) was the most uncommon and least found in all the samples. The Polymer Hazard Index (PHI) revealed the presence of extremely hazardous polymers such as polyurethane (PU), PVC, and PET in tissues, and Pollution Load Index (PLI) values indicate low pollution levels. Full article

Water quality degradation in China’s coastal waters poses a significant ecological challenge, yet the spatially varying predictors of key pollutants remain poorly quantified at the national scale. This study employed a Geographically Weighted Random Forest (GWRF) model integrating meteorological, marine, and socioeconomic data to analyze the associations between potential influencing factors and water quality variations in chemical oxygen demand (COD), dissolved inorganic nitrogen (DIN), and dissolved inorganic phosphorus (DIP) across China’s coastal waters. Results reveal significant spatial heterogeneity and clustering patterns, with distinct “High–High” hotspots and “Low–Low” cold spots for each indicator. The GWRF model showed modest improvements over traditional global models (RF, XGBoost) under spatially structured cross-validation, with significant improvement only for COD. COD variations were jointly associated with meteorological and marine factors, whereas nutrients (DIN, DIP) showed stronger associations with marine environments. Spatialized SHAP effects indicated regional specificities: cropland proportion showed positive effects on COD in Bohai Bay but negative effects in eastern Shandong Peninsula; upper ocean heat content and coastal population density emerged as key contributing factors for DIN; sea surface salinity was closely linked to DIP distribution patterns. These findings provide a systematic quantification of factor contributions at the national scale, offering spatially explicit evidence for formulating differentiated pollution control strategies for China‘s nearshore waters. Full article

Ichthyoplankton communities provide important information on spawning dynamics and early life-history processes of fish populations. This study investigated the species composition and seasonal occurrence of fish eggs and larvae in Yeongil Bay, in the East Sea of Korea, from January to December 2023. Samples were collected at seven stations and identified based on morphological characteristics and molecular analysis using mitochondrial DNA (COI and 16S rRNA). Thirty-six egg taxa (676 ± 739 eggs 1000 m⁻³) and 42 larval taxa (28 ± 35 larvae 1000 m⁻³) were identified. The dominant egg species were Engraulis japonicus (23.3%), Pseudopleuronectes herzensteini (11.8%), and Sardinops sagax (9.8%), while the dominant larval species were Sebastes inermis (29.7%), Sillago japonica (20.7%), and Sebastiscus marmoratus (5.5%). Egg abundance increased from spring and reached a peak in July, whereas larval abundance showed seasonal peaks in January and August. nMDS ordination showed seasonal variation in assemblage structure. Egg assemblages showed seasonal grouping patterns that corresponded with seasonal variation in surface water temperature and salinity, whereas larval assemblages showed relatively more complex seasonal patterns and were characterized by higher species richness and more extended seasonal occurrence. These results suggest that ichthyoplankton assemblages in Yeongil Bay exhibited seasonal variation in species composition during the study period, with E. japonicus eggs comprising the dominant component of the summer ichthyoplankton assemblage. Furthermore, the combined use of morphological and molecular identification improved species-level resolution and provided baseline information for understanding seasonal variation in ichthyoplankton assemblages in this coastal ecosystem. Full article

Carbon sequestration is considered one of the key factors for sustainable development. The marshes of Aniva Bay (Sakhalin Island) are ecosystems currently undergoing intense natural carbon accumulation (450–930 g∙C∙m⁻²∙year⁻¹) 2–4 times higher than the average speed for similar ecosystems, making this area highly promising for the implementation of “carbon farms.” Carbon sequestration could be accelerated by installing structures on mudflats that capture suspended organic matter from tidal waters. A model experiment was conducted to assess the suitability and biocompatibility of logging waste from coniferous species (Picea ajanensis, Larix leptolepis, Abies sachalinensis) for such structures by simulating their immersion in seawater. The content of phenols and tannins in the resulting water extracts was determined, and the composition of water-soluble substances was analyzed by GC-MS. Extract toxicity was investigated using the halophilic test organism Artemia salina. The experiments revealed the release of tannins in concentrations of up to 14 mg/L, which is nearly 1.5 times the maximum permissible concentration (MPC) and could potentially negatively impact the coastal ecosystem. Furthermore, the concentration of tannins leached from L. leptolepis bark exceeded the MPC by a factor of 5.5. A critical finding is the presence of highly toxic compounds in wood waste, for which targeted analysis is absent in state regulatory documents for hazard assessment. Specifically, immersion of A. sachalinensis wood led to the leaching of juvabione into saltwater at concentrations causing 100% mortality in Artemia salina. Based on the results, the most promising species for the terraformation of mudflats is the use of P. ajanensis logging waste. Full article

Typhoon disaster chains—cascading sequences of hazards triggered by tropical cyclones—pose significant risks to highly urbanized coastal regions. However, quantitative modelling of their stochastic evolution, including both propagation probabilities and temporal dynamics, remains limited. This study develops a typhoon disaster chain evolution model by integrating the FBIREC (Factor-Bearing body- Incident-Response-Environment-Consequence) scenario representation framework with a Graphical Evaluation and Review Technique (GERT) stochastic network. The model is applied to the Guangdong–Hong Kong–Macao Greater Bay Area using Typhoon Mangkhut (2018) as a case study. Ten cascading event sequences are identified, and their transmission probabilities and expected durations are calculated. The model reproduces the observed event probabilities for Typhoon Mangkhut with high fidelity, with a mean absolute error of 4.31% and a coefficient of determination R² = 0.816. Power facility damage was identified as one of the most influential infrastructure nodes, exhibiting high propagation potential to multiple downstream service systems. The disaster chain unfolds across two temporal scales: short-term risks (0–48 h) and long-term risks (>48 h), providing quantifiable targets for phased emergency response planning. The proposed framework provides a methodological reference that can be adapted to other typhoon-prone regions following case-specific re-parameterization. Full article