Search Results (28)

This study addresses the issues of sparse observations from buoys in the tropical Indian Ocean and systematic biases in reanalysis products by proposing a daily-mean wind speed reconstruction framework that integrates multi-source meteorological fields. This study also considers the impact of different source domains on model pre-training, with the goal of providing reliable data support for wind energy assessment. The model was pre-trained using data from the Americas and tropical Pacific buoys as the source domain and then fine-tuned on Indian Ocean buoys as the target domain. Using annual leave-one-out cross-validation, we evaluated the model’s performance against uncorrected ERA5 and CCMP data while comparing three deep reconstruction models. The results demonstrate that deep models significantly reduce reanalysis bias: the RMSE decreases from approximately 1.00 m/s to 0.88 m/s, while R² improves by approximately 8.9% and 7.1% compared to ERA5/CCMP, respectively. The Branch CNN–Transformer outperforms standalone LSTM or CNN models in overall accuracy and interpretability, with transfer learning yielding directional gains for specific wind conditions in complex topography and monsoon zones. The 20-year wind energy data reconstructed using this model indicates wind energy densities 60–150 W/m² higher than in the reanalysis data in open high-wind zones such as the southern Arabian Sea and the Somali coast. This study not only provides a pathway for constructing high-precision wind speed databases for tropical Indian Ocean wind resource assessment but also offers precise quantitative support for delineating priority development zones for offshore wind farms and mitigating near-shore engineering risks. Full article

In inland waters, Atmospheric Correction (AC), including Adjacency Effect (AE) correction, is a major challenge for water quality retrieval using optical satellite data. This study evaluated three image pre-processing options for turbidity retrieval in the St. Lawrence River using Sentinel-2 (S2) and Landsat 8/9 (L8/9) imagery with the Light Gradient Boosting Machine (LightGBM) model: (1) No pre-processing, i.e., use of Top-of-Atmosphere (TOA) reflectance, (2) AC pre-processing, obtaining water-leaving reflectance (R_w) from AC for the Operational Land Imager lite (ACOLITE)’s Dark Spectrum Fitting (DSF) technique, and (3) AE pre-processing, correcting for the AE using T-Mart before obtaining R_w from DSF. Results demonstrated that AE pre-processing outperformed the other two options. For L8/9, AE pre-processing reduced the Root Mean Square Error (RMSE) and improved the median symmetric accuracy (ε) by 48.8% and 19.0%, respectively, compared with AC pre-processing, and by 48.5% and 50.7%, respectively, compared with No pre-processing. For S2, AE pre-processing performed better than AC pre-processing and also outperformed No pre-processing, reducing RMSE by 28.4% and ε by 50.8%. However, No pre-processing yielded the lowest absolute symmetric signed percentage bias (|β|) among all pre-processing options. Analysis indicated that AE pre-processing yielded superior performance within 0–300 m from shore than other options, where the AE influence is strongest. Turbidity maps generated using AE pre-processing were smoother and less noisy compared to the other pre-processing options, particularly in cloud-adjacent regions. Overall, our findings suggest that incorporating AE correction through T-Mart improves the performance of the LightGBM model for turbidity retrieval from both L8/9 and S2 imagery in the St. Lawrence River, compared to the alternative pre-processing options. Full article

Conserving near-shore island endemics requires workflows that are robust to small, spatially clustered samples and that translate Species Distribution Model (SDM) into regulation-ready actions. We formalize a transferable SDM-to-action blueprint—(i) cluster-aware spatial holdout (leave-one-cluster-out, LOCO), (ii) conservative, high-specificity binarization paired with simple ecological filters, and (iii) explicit area-band uncertainty—and apply it to the Ulleungdo (Republic of Korea) endemic Scrophularia takesimensis. We combined 2008–2024 field records with a 5 m resolution MaxEnt model (linear–quadratic features; regularization RM = 1.40) using 28 unique presences versus 744 background points sampled within an accessible coastal belt (300 m from shore). Under LOCO, the model generalized well (AUC = 0.984 ± 0.014; partial AUC at specificity of at least 0.90 = 0.935; RelRMSE = 0.107) and mapped a narrow near-shore suitability belt with a continuous northern–northeastern core and fragmented southern–eastern satellites. To obtain a regulation-ready map, we converted continuous suitability to binary using a cutoff that achieved specificity of at least 0.98 under spatial holdout (threshold: 0.472; baseline: 300 m) and applied two ecological filters (retain areas within 90 m of shoreline; remove patches < 75 m²), yielding a CORE of 1.148 km² that captured 71.4% of recent records with zero leakage beyond the belt after post-processing. Accessible-mask sensitivity (masks of 300, 450, and 600 m) bounded the post-processed CORE to 0.930–1.593 km² (coverage: 0.607–0.789), which we carry forward as a planning area band. We translate these results into a tiered plan: protect the near-shore core, reconnect the fragmented southern and eastern stretches, and survey the highest-ranked coastal segments. Beyond this case, the blueprint generalizes to other small-n near-shore endemics, offering a transparent path from the SDM to policy while clarifying that, given static predictors, inferences concern present-day suitability rather than climate change forecasting. Full article

Coastal water quality is crucial for ecosystem services, supporting biodiversity and tourism. However, high tourist influxes often overwhelm wastewater treatment plant (WWTP) capacities, leading to untreated discharge and eutrophication, which severely impacts bathing water. Water quality monitoring is currently limited to selected points at the beach and oceanographic sampling, which requires depths >20 m offshore, leaving a gap of measurements between 1 and 50 m from the beach. To resolve this gap, our study proposes a low cost-effective sampling and monitoring method by using a kayak with a submersible fluorometer FlowCAM, as well as fecal bacteria detection and quantification. The kayak sampling was carried out during high- and low-tourism seasons in coastal bathing waters surrounded by Marine Protected Areas. The results show a patchy phytoplankton distribution, with chlorophyll a concentration up to 5.5 μg/L, indicating local fertilization. The observed floating organic matter patches were fecal bacteria free, while effluents of the WWTP to the Jate river and shore exceeded the legal limits for bathing water. These results suggest that wastewater treatment was overwhelmed during the high-tourism season, likely discharging wastewater into the river that flows into the shore. These findings are discussed in a sustainable development and socioeconomical context. Full article

In addressing the increasing challenges associated with automation, alternative fuels, and regulatory compliance within the maritime industry, the well-being of seafarers has become a critical determinant of workforce stability and career sustainability. This study investigates the impact of shore leave policies on seafarers’ well-being and turnover intention by applying the Analytical Hierarchy Process (AHP). The study delineates four principal criteria—mental well-being, physical health, work–life balance, and organizational support—and evaluates their sub-criteria via expert assessments from two distinct cohorts, each comprising 30 participants: maritime human resource professionals and seafarers working alongside related stakeholders. The outcome designates organizational support as the most influential criterion, with shore leave flexibility and financial incentives identified as the top-ranked sub-criteria. In contrast, mental well-being has the lowest overall weight, indicating that while its significance is acknowledged, it is frequently overshadowed by structural and financial factors. The findings underscore the need for shipping companies and policymakers to formulate flexible and financially supported shore leave policies to bolster seafarer retention and overall job satisfaction. This study enhances literature concerning sustainable seafaring careers and provides strategic recommendations for optimizing the management of shore leave policies within the maritime industry. Full article

Posidonia oceanica is an endemic seagrass of the Mediterranean Sea, forming extensive meadows and providing valuable ecosystem services underwater as well as on the shore. P. oceanica constantly generates new leaves while shedding the older ones. The latter may be deposited on the shoreline, forming “banquettes” that exhibit variable thickness, ranging from a few centimeters to several meters. These deposits act as natural barriers against coastal erosion, preventing sand loss and dissipating wave energy. Moreover, the degradation of the washed-up leaves releases large amounts of nutrients, relevant for the coastal food web. However, the presence of banquettes in touristic areas is often perceived as a nuisance, thus leading to their removal by local administrations. This study proposes a multidisciplinary approach for the assessment of P. oceanica banquettes along the coastline of the Campania region (Southern Italy), estimating their biomass and the associated concentrations of nutrients and other chemical elements, with the final aim to assess the potential loss of natural capital and ecosystem services due to their removal. Regional estimates show that approximately 40 tons of C are stored annually in the beached biomass, representing a potential carbon loss associated with their removal. The results highlight the crucial role that P. oceanica banquettes play in the blue carbon cycle and provide valuable insights to support their sustainable management. Full article

Extracts from natural waste like bark or leaves are great sources of phytochemicals, which contain functional groups (hydroxyl, carboxylic, vinyl, allyl) attractive in terms of polymer synthesis. In this study, the synthesis of epoxy with an extract of Scots pine bark as a natural co-hardener was evaluated. Ultraviolet-visible (UV-Vis) spectroscopy was used for the identification of phytochemicals with conjugated dienes and quantification of TPC. Also, the total solid content (TSC) of representative extracts was calculated. The best extract in terms of total phenolic content (TPC) value was selected as a co-hardener and investigated using differential scanning calorimetry (DSC) for thermal effects and attenuated total reflectance Fourier transform infrared spectroscopy (ATR FTIR) for reactions between functional groups. Also, the mechanical properties (flexural modulus, flexural strength, impact strength, Shore D hardness) and density of composition were obtained for extract-based epoxy and compared to reference sample values. Results were discussed in terms of future research and improvement of compositions. Also, potential applications were proposed. Full article

This paper demonstrates the benefits that high-frequency surface wave radars (HFSWR) are bringing to maritime safety and security in off-shore activities at over the horizon distances. As a primary means for remote sensing of marine and maritime environment, a network of HFSWRs is deployed in the western part of the Gulf of Guinea and covers an area of over 100 km². Alongside HFSWRs, usual maritime sensors are utilized for vessel tracking as well, however, only satellite automatic identification systems (SAIS) and land automatic identification systems (LAIS) are capable of covering over the horizon distances. Unfortunately, both LAIS and SAIS require vessel cooperation in order to provide any data, which is often abused by vessels conducting illegal activities. Here, analysis is done in which AIS and HFSWR data are compared in order to identify a pattern of behavior of non–cooperative vessels (vessels with onboard AIS devices turned off) so a proper risk assessment may be achieved. It is shown that typical patterns can be easily recognized for two illegal activities which plague the waters where this study is conducted. Those illegal activities are oil bunkering and piracy, both conducted off-shore and out of the reach of the usual coastal sensors such as X or S band radars. Furthermore, tracks created whilst conducting illegal activities are easily distinguishable from others in the overall operational picture. Additionally, it should be pointed out that numerous vessels are switching off their AIS devices when they leave the coastal regions in order to avoid detection by pirate vessels. This behavior can also be easily recognized and must not be mixed with the illegal activities mentioned above. Full article

The COVID-19 pandemic burdened the working and living conditions of seafaring personnel with particular challenges. The present study investigated the health and occupational burden of 301 multinational seafarers from merchant ships using self-administered questionnaires. The survey was carried out between September and November 2021 on the occasion of SARS-CoV-2 vaccinations at the Port of Hamburg, Germany. Participants generally reported good physical and mental health status while general burden perception increased compared to pre-pandemic levels. Three-quarters of seafarers reported experiencing shore-leave denial at least once throughout the pandemic. In summary, the study reveals the substantial impact of the COVID-19 pandemic on the perceived occupational burden of seafaring personnel. Full article

Hydrocharis morsus-ranae is a free-floating species growing in lakes and slow-flowing rivers near the shore in Europe and Western Asia, and as an invasive plant in the USA and Canada. Light-requiring plants of this species can also grow in the shade, up to about 30% of full sunlight. In this paper we present the data about the photosynthetic apparatus of sunny and shady H. morsus-ranae plants grown in the sun and in the shade in nature. Methods of light and transmission electron microscopy, biochemistry, chlorophyll fluorescence induction as well as the principal component analysis were used. It was found that leaves of plants growing in shade differed from those in the sun with such traits as thickness of a blade, palisade and spongy parenchyma, ultrastructure of chloroplasts, and quantum efficiency of photosynthetic electron transport, the content of chlorophylls and carotenoids, anthocyanins and phenilpropanoids. By these traits, H. morsus-ranae shady plants are similar with shade-bearing plants that indicates their adaptation to light intensity lowering. The ordination plots (PCA) suggested a clear structural and functional shift of plants growing in different lighting showing relationship to light changes in the natural environment. Thus, our results displayed the high phenotypic plasticity of the H. morsus-ranae photosynthetic apparatus, which ensures its acclimation to changing light environment and wide distribution of this species. Full article

Cordulegaster heros is a Balkan species with a disjunctive area extending into Central Europe. The population in the Chřiby Mts. in the southeastern Czech Republic is the northernmost population, and this population was intensively studied from 2010 to 2021 to establish basic data on its abundance. In the territory, the geomorphological characteristics of streams, characteristics of sediment in streams, habitat, emergence time, and period of flight were recorded, and population viability was evaluated. Larvae were recorded in 10 small forest streams (altitude of 235–426 m a.s.l.), with an average minimum width of 51.9 cm, an average maximum width of 177.7 cm, an average minimum depth of 6.5 cm, an average maximum depth (in pools) of 21 cm, and an average stream gradient of 1.9 grades. The sediments in each stream exhibited a grain size distribution with an average fraction less than 0.05 mm represented by 6.3%, a fraction of 0.05–0.1 mm represented by 21.1%, a fraction of 0.1–2 mm represented by 52.1%, a fraction of 2–5 mm represented by 12.1%, a fraction of 5–20 mm represented by 8%, and a fraction of 20+ mm represented by 0.3%. The larval abundance was 0.1–6.7 larvae per 1 m² of suitable sediment. The emergence period was recorded from 28 May to 1 July. The emergence site was categorized as larvae-dominated plant leave (57% of cases), plant stalks (21%), and tree trunks (17%). Exuviae occurred at an average of 154 cm at horizontal distance from the shore and an average vertical height of 77 cm above the ground. The average total distance of larval movement was 205 cm. The flight period in 2021 was recorded from 15 June to 11 August with peak flight activity noted in the third week of June. The northernmost population of C. heros was evaluated as viable and stable. Full article

No-take areas are key instruments to promote the effectiveness of Marine Protected Areas (MPAs), particularly concerning the protection of endangered species such as the dusky grouper (Epinephelus marginatus). However, despite the establishment of no-take areas and the prohibition of catching this species in a southwestern Portuguese MPA (SACVMP—‘Sudoeste Alentejano’ and ‘Costa Vicentina’ Marine Park) since 2011, there is still no evidence of population recovery. By using acoustic biotelemetry, this work aimed to evaluate the feasibility of restocking hatchery-reared adult dusky groupers in two no-take areas within the SACVMP. In 2019 and 2021, thirty groupers were tagged with acoustic transmitters and the site attachment and movements of the groupers were assessed in the releasing sites (no-take areas). None of the tagged fish settled down in either of the areas, leaving the no-take areas mainly at dusk and night. Some individuals displayed extended movements of more than a hundred kilometers along the Portuguese coast which was rarely reported for this species. At least in some coastal stretches, those movements were performed close to the shore, which may evidence the importance of coastal MPAs to protect and promote the connectivity of species more associated with rocky reef habitats. Following studies should focus on the conditions that promote site attachment and fidelity by hatchery-reared dusky groupers so that future large-scale restocking programs can be successful in MPAs with appropriate habitats. Full article

Marine Protected Areas (MPAs) have played an important role in the protection of endangered species such as the dusky grouper (Epinephelus marginatus), and the no-take areas have been particularly crucial for this purpose. Yet, despite the establishment of no-take areas and the legislation banning dusky groupers’ catches since 2011 in a southwestern Portuguese MPA (SACVMP—‘Sudoeste Alentejano’ and ‘Costa Vicentina’ Marine Park), there is still no evidence of this population’s recovery. In the face of this, the present work aimed to monitor the experimental hatchery-reared adult dusky groupers’ restocking of two no-take areas of SACVMP with acoustic biotelemetry. In 2019 and 2021, thirty groupers tagged with acoustic transmitters were released in two no-take areas, and the site attachment and their movements were assessed. None of the tagged fish set residency in either of the releasing areas, mostly leaving there at dusk and night. A rarely reported event for this species was also observed, as some individuals moved for more than a hundred kilometers along the Portuguese coast. At least some of those ranging movements were performed close to the rocky shore, which may point out the importance of coastal MPAs in promoting the connectivity of fish species associated with rocky reef habitats. Future studies must focus on the conditions that promote the site attachment and the site fidelity of released hatchery-reared dusky groupers so that large-scale restocking programs can be successfully implemented in MPAs with appropriate habitats. Full article

The molecular genetic mechanism of Turner syndrome (TS) still leaves much to be discovered. Methods: TS (45X0) patients and age-matched controls (46XX and 46XY) were selected. The nanopore sequencing combined with trio-whole exome sequencing (trio-WES) were used for the first time to investigate TS. Results: Thirteen TS (45X0) patients and eight controls were enrolled. Trio-WES analysis did not find any pathogenetic or likely pathogenic variants except X chromosome (chrX) deletion. The average methylation levels and patterns of chrX in 45X0 and 46XY were similar, and significantly higher than in 46XX (p = 2.22 × 10⁻¹⁶). Both hyper-methylation and hypo-methylation were detected in the CpG island (CGI), CGI_shore, promoter, genebody, and PAR1-region, while in the transposon element inactivation regions of the chrX and hypermethylation were predominant. A total of 125 differentially methylated genes were identified in 45X0 compared to 46XX, including 8 and 117 hypermethylated and hypomethylated genes, respectively, with the enrichment terms of mitophagy, regulation of DNA-binding transcription factor activity, etc. Conclusions: The results suggest that the methylation profile in patients with TS might be determined by the number of X chromosomes; the patterns of methylation in TS were precisely associated with the maintenance of genomic stability and improvement of gene expression. Differentially methylated genes/pathways might reveal the potential epigenetic modulation and lead to better understanding of TS. Full article

Seaports are well known as the medium that has evolved into the central link between sea and land for complex marine activities. The growth in maritime logistics particularly necessitates a large volume of energy supply in order to maintain the operation of sea trade, resulting in an imbalance between generation and demand sides. Future projections for three major concerns show an increase in load demand, cost of operation, and environmental issues. In order to overcome these problems, integrating microgrids as an innovative technology in the seaport power system appears to be a vital strategy. It is believed that microgrids enhance seaport operation by providing sustainable, environmentally friendly, and cost-effective energy. Although microgrids are well established and widely used in a variety of operations on land, their incorporation into the seaport is still limited. The involvement of a variety of heavy loads such as all-electric ships, cranes, cold ironing, and buildings infrastructure renders it a complicated arrangement task in several aspects, which necessitates further research and leaves space for improvement. In this paper, an overview of the seaport microgrids in terms of their concepts and operation management is presented. It provides the perspectives for integrating the microgrid concept into a seaport from both shore side and seaside as a smart initiative for the green port’s vision. Future research directions are discussed towards the development of a more efficient marine power system. Full article