Search Results (2,971)

Cyanobacterial harmful algal blooms are an increasing concern for wildlife health, particularly in eutrophic wetlands, yet well-documented avian cases supported by environmental, pathological, and toxicological evidence remain scarce. This study describes a sentinel case of probable microcystin toxicosis in a Red-gartered coot (Fulica armillata) from Laguna Petrel, a protected coastal wetland in central Chile, during a broader wildlife mortality event. Surface-water monitoring included nutrient analyses, in situ physicochemical measurements, phytoplankton assessment, and cyanotoxin quantification. The evaluated bird was documented alive with severe motor impairment, euthanized, and examined by gross necropsy, histopathology, and tissue toxicology. Water analyses showed elevated nutrients, persistently alkaline and highly productive conditions, marked dominance of Microcystis aeruginosa, and high concentrations of microcystin-LR, microcystin-RR, microcystin-YR, and nodularin. The bird showed marked hepatic lesions at necropsy, histopathological changes compatible with acute hepatotoxic injury, and detectable microcystin-LR in lyophilized liver tissue. Taken together, these findings support a diagnosis of probable microcystin toxicosis in this individual. This case highlights the value of waterfowl as sentinels of ecosystem health threats and underscores the importance of integrated monitoring in protected coastal wetlands potentially affected by toxic cyanobacterial blooms. Full article

Mangrove ecosystems provide critical coastal protection, biodiversity support, and carbon storage, yet they remain vulnerable to degradation caused by coastal development, pollution, and climate-related pressures. This study monitors mangrove dynamics in Al-Birk, Asir Region, Saudi Arabia, using Google Earth Engine (GEE), multi-temporal Landsat imagery, spectral indices, and Random Forest (RF) classification. Landsat imagery from 2016 to 2021 was processed to derive NDVI, MSAVI2, EVI, and NDWI, and supervised RF classification was applied to map annual mangrove extent and associated land-cover classes. The RF classifier achieved an overall accuracy of 92.5% and a Kappa coefficient of 0.89. Results indicate that classified mangrove extent increased from approximately 1069 ha in 2016 to 1540 ha in 2021, representing a net gain of 471 ha and a 44% increase over the study period. A localized decline was detected between 2020 and 2021, indicating spatially uneven vegetation dynamics. The findings provide a spatial baseline for monitoring mangrove change and supporting coastal conservation planning in Saudi Arabia. While the detected expansion is temporally consistent with ongoing restoration initiatives, the study does not establish direct causality between policy interventions and observed spatial changes. Full article

Plastic pollution has emerged as one of the most pervasive environmental challenges, with microplastics (MPs) widely distributed across marine ecosystems worldwide. This study aimed to assess the uptake of MPs by key fish and invertebrate species from different locations in the coastal zone of the Bulgarian Black Sea. Fish were collected during routine monitoring surveys in September–November 2024, while invertebrates were obtained via scuba diving. The presence of MPs in fish stomachs and invertebrate soft tissues, and their polymer composition, shape and size were analyzed using an Agilent 8700 LDIR Chemical Imaging System. Potential biological effects of ingested MPs were evaluated by an integrated Specific Oxidative Stress (SOS) index. The results revealed MP uptake levels comparable to those reported globally. Small-sized particles (<50 µm) with rounded shapes were most abundant across studied taxa. Polymer composition varied considerably depending on species and sampling region, indicating differences in exposure sources and environmental conditions. Oxidative stress levels in both fish and invertebrates showed substantial interspecific variation, and clear differences between the northern and southern region of the Bulgarian Black Sea. Overall, elevated uptake of MPs appears to contribute to oxidative stress in marine organisms, potentially affecting their health status, resilience, and adaptive capacity, as reflected by increased SOS index values. Full article

The finless porpoise (Neophocaena asiaeorientalis) is a species frequently observed in Korean coastal waters that remains highly vulnerable to bycatch and habitat disturbance. To develop effective conservation strategies, it is essential to understand their acoustic behavior and environmental preferences. This study utilized Passive Acoustic Monitoring to investigate the acoustic characteristics and activity patterns of finless porpoises in coastal waters near cage aquaculture farms from September to October 2021. A total of 372,707 clicks and 175,119 click trains were identified. Mean acoustic parameters were peak frequency 122.0 ± 11.1 kHz, 3 dB bandwidth 15.4 ± 12.0 kHz, 10 dB bandwidth 45.3 ± 16.1 kHz, and ICI 39.0 ± 34.8 ms. Click activity exhibited a distinct diel pattern, with significantly higher activity during the early morning and nighttime. Generalized Additive Model analysis revealed significant non-linear relationships between click activity and tide, temperature, salinity, and hour. Specifically, click activity decreased with rising temperatures and lower salinity, while the effect of tide was relatively limited. These findings provide critical baseline data for the development of acoustic deterrent devices tailored to Korean marine environments and contribute to the management of bycatch mitigation and coastal ecosystem conservation. Full article

As the core pillar of international trade, the global shipping industry has seen its carbon and pollutant emissions become a key challenge in global environmental governance. Statistics indicate that ship carbon emissions account for 3% of the world’s total anthropogenic CO₂ emissions, while contributing 20% of global NO_x and 12% of SO₂ emissions, posing a serious threat to coastal ecosystems and public health. In response to the International Maritime Organization (IMO) “Net Zero Framework” and national green shipping policies, the transformation of ship power systems toward low-carbon and zero-carbon operation has become an inevitable trend. This paper systematically reviews the research progress and application status of green energy materials for ships, focusing on the working principles, technical characteristics, and engineering application cases of solar photovoltaic (PV) materials, wind energy utilization technologies, fuel cell materials, and alternative clean energy fuels (e.g., liquefied natural gas (LNG), methanol, and hydrogen energy). It also discusses the integration mode and optimization strategy of multi-energy hybrid power systems. The research findings show that solar photovoltaic technology has achieved large-scale application in coastal ships; hydrogen fuel cells are suitable for long-range ocean navigation scenarios due to their high energy density; LNG and methanol have become the current mainstream alternative fuels, relying on mature infrastructure; and hybrid energy systems can significantly improve power supply reliability and emission reduction efficiency through multi-energy complementarity. Finally, aiming at the existing bottlenecks (e.g., cost, energy storage, and safety) of various technologies, future development directions are proposed. This study provides a reference for the technological breakthrough and engineering practice of green energy power systems for ships and contributes to the realization of the “carbon neutrality” goal in the global shipping industry. Full article

Derelict crab pots (“ghost pots”) cause bycatch mortality, habitat degradation, and lost harvest in shallow coastal ecosystems. Existing detection and recovery programs rely on expert operators and high-cost sonar, limiting coverage and reproducibility. Here, we present GhostVision, an open-source framework that integrates low-cost consumer side-scan sonar with modern object-detection models to enable scalable, rapid post-processing and mapping of derelict gear. Mobile Mapping Units (MMUs) equipped with off-the-shelf fishfinders surveyed more than 1500 acres in Delaware’s Inland Bays between 2020 and 2022. Three architectures (YOLOv12, YOLOv26, RF-DETR) were trained on 3110 manually annotated sonar images and evaluated with both dataset-centric metrics and full pipeline implementation. YOLOv12 showed the strongest untuned operational performance (F1 = 0.512; recall = 0.922), while post-processing optimization produced comparable performance across all three models (F1 ≈ 0.71–0.73). Across 11 complete test recordings, end-to-end processing required only 8.87–9.79% of survey time (approximately 10–11× faster than real-time), supporting same-day analysis and recovery workflows. GhostVision can foster community engagement in derelict crab-pot removal by pairing low-cost sonar with AI to aid recovery efforts at management-relevant scales. By lowering financial and technical barriers, GhostVision provides a reproducible pathway for large-scale stewardship and supports future extensions to multi-class detection and autonomous platforms. Full article

The protected fan mussel Pinna nobilis (Linnaeus, 1758) is a key ecosystem-engineering species in Mediterranean coastal ecosystems, historically providing important regulating ecosystem services—particularly nutrient removal and shell-based carbon storage—as well as the ecological function of large-scale biofiltration. Prior to the mass mortality event in 2016, the Greek population was estimated at approximately 2.66 × 10⁹ individuals. This is associated with an annual gross shell carbon storage of 13,689–108,139 t “C”, together with 304.7–2988.3 t “N” and 49.7–450.5 t “P” retained in shell material, valued at EUR 8.14–76.6 million yr⁻¹ using replacement-cost proxies. These values represent a gross shell carbon storage rather than a net ecosystem carbon sequestration, due to the fact that metabolic fluxes and remineralization may partially offset long-term retention. Furthermore, P. nobilis performed a substantial biofiltration function, filtering 6.07 × 10¹¹–6.85 × 10¹² m³ of seawater per year (2.89–32.53 turnovers of the 30 m coastal zone). The mass mortality event led the population to a decline by >81%, reducing the value of nutrient retention and gross shell carbon storage to EUR 1.31–13.47 million yr⁻¹ and filtration capacity to 1.15 × 10¹¹–1.30 × 10¹² m³ yr⁻¹. Using an illustrative order-of-magnitude replacement-cost approach, we estimate that by reproducing the lost biofiltration function through engineered systems, we would require approximately EUR 1–5.2 billion annually which indicates the magnitude of natural capital lost and the utmost importance of P. nobilis recovery for Greek coastal ecosystems. Full article

Seagrasses are vital ecosystem engineers and habitat architects in coastal environments, with Posidonia oceanica in the Mediterranean playing a crucial role as an indicator of ecological health. As an endemic and vulnerable species, P. oceanica meadows are highly susceptible to environmental degradation, underscoring the importance of non-destructive monitoring techniques. Traditional SCUBA-based surveys are accurate but resource-intensive and difficult to scale, especially for estimating shoot density and leaf length. This study applies a conservative acoustic-based approach to assess Posidonia oceanica biometrics, habitat characteristics, and ecological status along the Turkish Levant coast. The method offers a non-destructive alternative to SCUBA surveys and addresses a regional knowledge gap in Mediterranean seagrass monitoring. Acoustic data collected during winter and summer 2019 along the Turkish Levant coast were analyzed to estimate seagrass biometrics and derive ecological indicators, with validation via SCUBA observations. Results show that acoustic methods can reliably estimate shoot density, leaf area index, and canopy height. They provide broad-scale coverage and efficiency, though further refinement is required to improve calibration across depths and substrates. While acoustic methods provide broad, non-invasive coverage, they are affected by spatial and temporal variability that SCUBA surveys capture more reliably. Calibration of the POSIBIOM (vers 1.1) algorithm was based on specimens collected at 15 m depth on rocky substrates. While this provided consistent regression relationships, it may limit accuracy when extrapolated to habitats such as sand, mud, or matte. This study represents the first high-resolution, spatiotemporal mapping of P. oceanica meadows and benthic habitats along a significant portion of the Turkish Levant coast using acoustics alone. Overall, the study highlights the potential of acoustics as a scalable, non-invasive tool for seagrass monitoring. This approach contributes to ecosystem-based management and conservation strategies in the Mediterranean. Future work will focus on refining models to address bottom type- and depth-dependent acoustic responses and improve biometric accuracy. Full article

Marine oil spills pose a persistent threat to marine ecosystems and coastal economies, and their rapid and unpredictable spread requires timely and reliable monitoring. In X-band marine radar images, oil slicks usually appear as low-contrast dark targets embedded in heterogeneous sea clutter, making accurate segmentation particularly challenging. To address this problem, this study proposes a training-free two-stage oil slick detection framework that combines an improved Slick Boundary Ratio (SBR) feature with an improved Whale Optimization Algorithm (WOA). First, the improved SBR feature is used to extract the oil slick region of interest (ROI). Then, the improved WOA is employed to determine the global threshold for oil slick segmentation. Experimental results show that the proposed method achieves accurate and spatially coherent oil slick segmentation in complex radar backgrounds, with an Accuracy of 99.36%, a Precision of 85.73%, a Recall of 84.42%, an F1-score of 85.07%, and an Intersection over Union (IoU) of 74.01%. These results indicate that the proposed framework can effectively suppress false positives while maintaining strong detection sensitivity, thereby improving segmentation robustness in low-contrast marine radar scenes. Owing to its training-free design, the proposed method shows potential for shipborne and coastal oil spill monitoring applications. Full article

Marine coastal ecosystems provide a variety of habitats for biodiversity. However, they are affected by bycatch, the unintentional capture of non-target species during fishing operations such as gillnets, trammel nets, and longlines. To mitigate bycatch, modifications such as LED and UV lights in gillnets and trammel nets and C-type (circle) hooks in longlines have been studied worldwide. Yet, studies remain limited in Türkiye. This study aimed to evaluate the effectiveness of these gear modifications in small-scale fisheries along the Aegean coast of Türkiye. Paired trials were conducted to compare standard (control) and modified (LED, UV, or C-type hook) fishing gears. Trials resulted in four sea turtles caught in LED and UV nets with no significance. Other vulnerable species caught in UV trammel nets showed significance. Overall, modified gears showed a significant reduction in commercial species catch, while increasing non-target species captures. These preliminary findings contradict much of the literature, which generally reports these modifications as effective bycatch reduction tools. The results emphasize the necessity of developing regionally adapted gear modifications and conducting more extensive experiments to validate their performance. The implementation of locally optimized bycatch mitigation tools may help achieve a balance between marine conservation and the socioeconomic sustainability of small-scale fisheries. Full article

Benthic foraminifera, single-cell marine organisms found worldwide, represent an important component of seabed ecosystems. Due to their sensitivity to environmental pollution, they are often used as bioindicators, providing an efficient tool in toxicity studies. Among the pollutants affecting marine coastal and estuarine environments, persistent flame retardants, such as polybrominated diphenyl ethers (PBDEs), are frequently found. Low-level exposure to BDE-47, a PBDE congener, is known to affect organismal development. In this framework, this study aims to assess the effects of BDE-47 exposure on benthic foraminifera from coastal marine environments. Foraminifera specimens belonging to the symbiont-bearing Peneroplidae family were sampled and exposed to two different BDE-47 concentrations for up to 48 h. Vitality indicators such as changes in pseudopodial activity, movement, reproduction, loss of symbiont algae, and occasional mortality events were monitored during the experiment. Exposure to BDE-47 induced alterations in pseudopodial activity, movement, reproduction, and symbiont retention, with the progressive loss of vitality and limited mortality at increasing exposure levels, highlighting the sensitivity of this species to BDE-47. These findings suggest the harmful repercussions of PBDE pollution on marine coastal ecosystems, affecting benthic organisms and potentially contributing to biomagnification processes within the food web, with possible implications for human health. Full article

Cities are artificial ecosystems that suffer most from environmental issues and climate change. Urban Heat Island (UHI) effects represent an increasing challenge, especially for compact Mediterranean cities characterized by high population density and extensive impervious surfaces. This study assessed localized microclimatic conditions within the small Maltese coastal town of Isla through a 15-day summer field monitoring campaign. Air temperature, relative humidity, and wind speed were measured across urban locations characterized by different levels of vegetation coverage and thermal vulnerability. The analysis combined descriptive statistics, Mann–Whitney U testing, and Multiple Linear Regression (MLR) models. In addition, site-specific Nature-based Solutions (NbS) scenarios were proposed as context-sensitive strategies to support urban heat mitigation and climate resilience. The results highlighted distinct microclimatic responses between the sites investigated. In particular, the MLR analysis suggested that non-vegetated areas were more sensitive to short-term atmospheric variability associated with wind speed and relative humidity fluctuations. These findings suggest that urban vegetation may contribute not only to localized cooling, but also to increased microclimatic stability within compact Mediterranean urban environments. Full article

The atypical proliferation of Sargassum (Sargassum spp.) in the tropical Atlantic and the Caribbean Sea over the past decade has triggered an unprecedented environmental and socioeconomic crisis along the Mexican coastline. Continuous beaching events of this macroalga on the Riviera Maya have caused coastal ecosystem degradation, severe impacts on the tourism sector, toxic gas emissions during decomposition, and high cleanup costs. To address this challenge, the valorization of Sargassum as a raw material for synthesizing functional materials represents a sustainable management strategy. In this study, a superabsorbent hydrogel was developed from Sargassum biomass (collected in Cancún, Quintana Roo, in 2025) using an innovative process that bypasses the conventional cellulose isolation step. The biomass was subjected to high-energy milling (15 and 30 min) to prepare Sargassum powder, which was subsequently carboxymethylated using monochloroacetic acid. This modified biomass was then crosslinked with citric acid, a process evaluated at three different citric acid/carboxymethylated Sargassum mass ratios. The hydrogel synthesized with the lowest crosslinking agent ratio achieved a maximum water absorption capacity of 1160 wt%, a value that exceeds the typical absorption capacities of 700–900% for biopolymer hydrogels. Successful material formation was confirmed by Fourier transform infrared spectroscopy (FTIR), which revealed the characteristic functional groups of CMC and the ester bonds formed during crosslinking. Additionally, scanning electron microscopy (SEM) analysis showed a well-defined porous structure with pore sizes ranging from 8.5 to 19.5 µm, which is essential for its high absorption performance. This study demonstrates the feasibility of producing high performance hydrogels from Sargassum through a simplified, cost-effective, and environmentally friendly process. These findings open a promising avenue for the integrated management of this problematic biomass, transforming it into value-added materials with potential applications in agriculture, hygiene, and environmental remediation. Full article

Macrozoobenthic communities function as important bioindicators of natural and anthropogenic pressures in transitional ecosystems and contribute to ecosystem processes. Transitional systems, such as lagoons, estuaries and coastal ponds, exhibit strong physico-chemical variability, often intensified by anthropogenic pressures and climate change. Changes in macrozoobenthic communities across five Veneto Po Delta lagoons were assessed through long-term monitoring (2008–2025) conducted within the Water Framework Directive and additional monitoring activities. The macrozoobenthic communities were analysed to assess temporal variability and inter-lagoon differences in the Po Delta system; ecological indices were generally stable, but organism density showed significant interannual fluctuations, with marked declines in 2008, 2009, 2024, and 2025. Univariate and multivariate analyses identified phases of community restructuring driven by temporal shifts in species composition and relative abundance. These patterns may reflect the interacting effects of multiple stressors, including long-term anthropogenic pressures and the recent expansion of the invasive blue crab Callinectes sapidus, although causality was not assessed. Increases in water temperature and suspended solids were observed across all lagoons, potentially affecting benthic communities. Overall, this study provides an assessment of macrozoobenthic variability and a preliminary analysis of the factors that may have influenced it, highlighting patterns that warrant further investigations to elucidate the underlying mechanisms. Full article