Search Results (796)

This study provides a systematic analysis of the spatiotemporal distribution and trends in the frequency of significant wave height (SWH) exceeding level 5 (SWH > 2.5 m) and level 7 (SWH > 6 m) in the Northwest Pacific (NWP) for 1993–2024, which are defined as f₅ and f₇, respectively, as well as their correlations with major climate indexes. Our results indicate that (1) the high-value zones for the annual mean f₅ and f₇ are both located in the south waters of the Aleutian Islands, with maximum values of 58.0% and 6.4%, respectively. Winter’s contribution is greatest (maximum values of 96.9% and 16.8% per year), while summer’s is the smallest. (2) f₅ exhibits a significant decline trend across the entire NWP basin (of −0.15 to −0.30%/yr), with the steepest decline occurring in autumn (−0.69%/yr) and the shallowest in summer. f₇ exhibits a significant linear decrease in the open ocean east of Japan (−0.08%/yr) while showing a significant linear increase in the waters east of the Kamchatka Peninsula (0.08%/yr). Both variations peak in winter (maximum values of −0.27% and 0.30% per year) and are smallest in summer. (3) Seasonal and regional variations in climate index–f₅ and f₇ relationships reflect large-scale atmospheric modulation of waves. For example, the Oceanic Niño Index shows a predominantly negative correlation with f₅ in winter (maximum correlation coefficient r_m = −0.70) around the Luzon Strait, shifting to a significant positive correlation in summer (r_m = 0.70) across the extensive region east of Taiwan Island and the Philippines. The Pacific Decadal Oscillation index shows a significant positive correlation with f₇ in summer and autumn (r_m = 0.69) east of Taiwan Island and a strong negative correlation in winter (r_m = −0.77) to the east of Kamchatka Peninsula. Full article

Eight Pacific Island Countries and Territories (PICTs) have been validated by the World Health Organization (WHO) as having eliminated lymphatic filariasis (LF) as a public health problem. WHO recommends that these countries implement post-validation surveillance (PVS) to ensure resurgence has not occurred. Some PICTs proactively conducted LF PVS even in the absence of specific recommendations or best-practice guidelines at the time of implementation. We aimed to explore the barriers and facilitators to implementing LF PVS in PICTs, with a view to informing context-specific strategies and regional guidelines. Key informant interviews were held between March and September 2024 with 15 participants involved in LF and/or neglected tropical disease surveillance. Transcripts were analysed thematically using a generalised deductive approach. A conceptual framework was developed to summarise themes with two main streams of barriers identified. Stream One Barriers included limited awareness of, and guidelines for, PVS requirements and competing national health priorities. Stream Two Barriers included cost, resource, and logistical barriers to conducting PVS. Participants called for clearer, contextually tailored guidelines, improved communication from WHO, and integration within existing systems. This study highlights the urgent need for operational guidance, policy advocacy, and capacity strengthening to ensure sustainable LF PVS in PICTs. Incorporating local context and leveraging existing health structures will be essential to prevent disease resurgence and maintain gains achieved through elimination programmes. Full article

Thymic carcinoma (TC) is a rare and aggressive malignancy with poor prognosis, and its genomic landscape remains incompletely defined. Identifying the somatic alterations that shape TC biology is essential for improving diagnostic precision, developing targeted therapies, and informing early detection strategies. We performed a retrospective genomic analysis of 141 TC tumor specimens from 134 patients using de-identified data from the American Association for Cancer Research (AACR) Project GENIE^® database. Somatic mutations and copy number alterations (CNAs) were characterized, and statistical analyses were conducted to evaluate associations with patient demographics (sex, race) and tumor site (primary vs. metastatic). The cohort was predominantly male (56.7%) and White (56.7%). The most frequently altered genes were TP53 (27.7%), CYLD (17.6%), and CDKN2A (12.1%). Recurrent homozygous deletions at chromosome 9p21.3 involving CDKN2A and CDKN2B were common. Sex-stratified analysis revealed several significant male-specific alterations. Although the Pacific Islander subgroup was small (n = 2), preliminary analysis suggested enrichment of alterations in key cancer-associated genes, including TP53, BRCA1, and STAT5B, underscoring the need for diverse representation in TC genomics. Notably, MTOR mutations were significantly enriched in a subset of local recurrences and lymph node metastases (n = 3; q = 0.013), suggesting a potential role in disease progression. This large-scale genomic analysis reinforces the central involvement of TP53, cell-cycle control, and chromatin-modifying pathways in TC. The identification of sex-associated and race-associated mutational patterns, together with the enrichment of MTOR alterations in recurrent and metastatic disease, highlights biologically plausible mechanisms of progression and potential therapeutic vulnerabilities. These findings support the value of comprehensive genomic profiling in TC and emphasize the need for prospective, multi-omic studies to validate these observations and guide the development of more personalized treatment strategies. Full article

Interest in Zika virus (ZIKV, Orthoflavivirus zikaense) evolution and pathogenicity has attracted the attention of a wider circle of the research community ever since ZIKV emerged on the South American continent in 2015, after more or less island hopping across the Pacific Ocean from Southeast Asia on its way from Africa where it was first described in Uganda in 1947 [...] Full article

Arthropod-borne viruses (arboviruses) such as dengue, chikungunya, Zika, and yellow fever pose significant global health risks, with mosquitoes from the Aedes genus as the primary vectors responsible for human transmission. The Republic of the Marshall Islands (RMI), particularly the urbanized areas of Kwajalein and Majuro atolls, has experienced multiple outbreaks of dengue, Zika, and chikungunya with substantial health and economic impacts. Vector control remains the most effective method for reducing disease risk, but comprehensive data on local mosquito vector composition, distribution, and abundance are needed to guide new, effective control efforts. From 2022 to 2024, we conducted a longitudinal baseline assessment of mosquito abundance and species composition on Ebeye and nearby islets in Kwajalein Atoll, RMI, using BG-Sentinel traps and ovitraps. Aedes aegypti was the most prevalent species, accounting for 58% of all adult females collected across study locations, with higher relative abundances on Ebeye than on northern islets (4.7 vs. 2.3 per trap/night). Aedes albopictus was more abundant on northern islets (0.7 vs. 3.2 per trap/night), and Culex quinquefasciatus showed similar abundances (1.2 vs. 1.7 per trap/night). Rainfall and anthropogenic factors, including water storage practices and housing density, influenced mosquito abundance. These findings provide multi-seasonal baseline data to support targeted vector control strategies in RMI. Full article

Pacific Island communities have long navigated the challenges of climate change. Supporting adaptation options is critical for protecting livelihoods, especially given that these countries will continue to unfairly bear the brunt of global climate change impacts. Understanding and strengthening the capacity of individuals and communities to adapt is vital to ensure effective options are available. However, adaptive capacity is highly context-specific and explicit examples, particularly from the Pacific, remain limited. This study focuses on the experiences of women market vendors, for whom marketplaces are integral to food security, income generation, and cultural and social life. Building on existing global and regional frameworks, we assess the adaptive capacity of market vendors across Vanuatu through interviews with women market vendors (n = 69) and key informants (n = 18). The findings informed the development of a new, tailored adaptive capacity framework that identifies six key drivers: access to tangible resources, human assets, social assets, livelihood diversity and flexibility, systems of influence and mindsets, and decision-making capacity. This study presents a context-specific framework grounded in empirical evidence, offering insights for development and adaptation initiatives that aim to strengthen adaptive capacity. We encourage further research to apply and refine this framework across diverse Pacific contexts and sectors to deepen understanding of adaptive capacity and inform effective adaptation strategies. Full article

The marine environment in the South Pacific Island Countries (SPICs) is sensitive and vulnerable to climate change. While large-scale changes in this region are well-documented, national-scale analyses that address management needs remain limited. This study evaluated the performance of satellite-derived datasets—including sea surface temperature (SST), sea surface salinity (SSS), Secchi disk depth (SDD), chlorophyll-a (Chl-a), net primary production (NPP), and sea level anomaly (SLA)—against in situ observations, and analyzed their spatial and temporal variability across 12 national Exclusive Economic Zones (EEZs) during 1998–2023. Validation results presented that current satellite datasets could provide applicable information for EEZ-scale analyses. In the past decades, the SPICs experienced a general increase in SST and SLA, accompanied by marked within-EEZ heterogeneity in Chl-a and NPP variations, with Papua New Guinea exhibiting the largest within-EEZ inter-annual variability. In addition to monitoring, satellite data would help to constrain the uncertainty of CMIP6 results in the SPICs, subject to the accuracy of specific products. By 2100, Nauru might experience the most vulnerable EEZ, while the marine environment in the French Polynesian EEZ can keep relatively stable among all 12 EEZs. Meanwhile, CMIP6 projections in the Southeastern EEZs are more sensitive to satellite-based constraints, showing pronounced adjustments. Our results demonstrate the potential of combining validated satellite data with CMIP6 models to provide national-scale decision support for climate adaptation and marine resource management in the SPICs. Full article

We describe a new species of Desmoscolex collected from subtidal muddy sediments off Jindo Island, on the southern margin of Korea’s west coast. Desmoscolex (Desmoscolex) curuvus sp. nov. is distinguished by 17 main rings, a 9/8 somatic setal arrangement, subdorsal setae with a slightly swollen and hollow distal end, an oval head with laterally extended foreign material, a rounded amphidial fovea confined within the head region, and broad cephalic setae bearing a fine central canal with lateral membranes. The terminal ring is strongly bent ventrally. Females exhibit pronounced sexual dimorphism, including a pair of dorsal setae on the thirteenth main ring and a thicker terminal ring (maximum width 25–26 μm in males and 24–31 μm in females). High-resolution scanning electron microscopy (SEM) observations revealed a distinctive lip-region ultrastructure composed of a tuberculate membrane and six fragment-like membranous elements, representing a rare configuration within the genus. By documenting a new species possessing membranous structures in the cephalic setae and providing detailed ultrastructural characterization of the lip region, this study offers important new evidence for refining species delimitations in Desmoscolex. These findings underscore the diagnostic value of lip-region morphology and highlight the need for targeted sampling and further ultrastructural analyses to better resolve the hidden morphological diversity of the genus, particularly in the underexplored northwestern Pacific. Full article

Highly pathogenic avian influenza (HPAI) A(H5N1) clade 2.3.4.4b has recently emerged as a major threat to wildlife, agriculture, and public health due to its expanding host range and the increasing frequency of spillover into mammals. In July–August 2023, the mass death of over 3500 northern fur seals (Callorhinus ursinus) and at least one Steller sea lion (Eumetopias jubatus) was recorded on Tyuleniy Island in the Sea of Okhotsk, Russia. Two HPAI A(H5N1) viruses were isolated from fur seal carcasses and designated A/Northern_fur_seal/Russia_Tyuleniy/74/2023 and A/Northern_fur_seal/Russia_Tyuleniy/75/2023. Both viruses exhibited high pathogenicity in chickens (IVPI 2.7–3.0) and mice (MLD₅₀ 1.9–2.5 log₁₀EID₅₀/mL), with distinct differences in disease progression, histopathology, and organ tropism. Experimental infection of mice revealed that strain A/74/2023 induced more severe pulmonary and neurological lesions than A/75/2023. Whole-genome sequencing and phylogenetic analysis demonstrated close relatedness to HPAI H5N1 strains circulating in the Russian Far East and Japan from 2022 to 2023, with several mutations associated with mammalian adaptation, including NP-N319K and, in one isolate, PB2-E627K. According to our findings, northern fur seals (Callorhinus ursinus) on Tyuleniy Island acted as spillover hosts for the highly pathogenic avian influenza (HPAI) H5N1 virus of clade 2.3.4.4b. Furthermore, the high population density of fur seals and the extensive mortality observed during the outbreak highlight these animals’ potential role as another vessel for the evolution of avian influenza viruses. This study represents the first documented case of HPAI H5N1 in pinnipeds in the North Pacific region and supports previous reports indicating that pinnipeds, including northern fur seals, are highly susceptible to HPAI H5N1 clade 2.3.4.4b viruses. Full article

This scoping review aimed to identify and synthesise spatially relevant environmental, demographic, and socio-economic factors associated with vector-borne diseases (VBDs) in Pacific Island Countries and Territories (PICTs), a region particularly vulnerable due to its ecological and climate diversity. A systematic search of PubMed, Scopus, and Web of Science was conducted in March 2025 with no time restrictions, yielding 3008 records. After applying the inclusion criteria, 21 studies were selected for analysis. Environmental factors such as temperature, precipitation, and land cover were consistently associated with increased burden of malaria, dengue, and lymphatic filariasis, while associations with elevation and flooding were mixed or inconclusive. Demographic factors, including population density and household composition, were found to be associated with disease occurrence, although the direction and the strength of these associations varied. Three studies reported a negative association between population density and disease outcomes, including lymphatic filariasis in American Samoa and dengue in New Caledonia. Spatial socioeconomic factors such as low income, unemployment, and limited education were positively correlated with disease burden, particularly lymphatic filariasis and dengue. These findings underscore the importance of spatial determinants in shaping VBD transmission across PICTs and highlight the utility of spatial risk mapping to inform geographically targeted vector control strategies. Notably, infrastructure, health care access, and intra-island mobility remain underexplored in the literature, representing critical gaps for future research. Strengthening surveillance through spatially informed public health planning is essential to mitigate disease burden in this climate-sensitive and geographically dispersed region. Full article

US-affiliated Island nations and territories are home to diverse populations, including substantial Indigenous communities who have extensive exposure to marine and geoscience content, with some of their knowledge sustained through heritage practices. Despite this demographic presence, Indigenous peoples of the Pacific remain notably underrepresented in STEM fields, particularly in the geosciences and marine sciences. Beyond an equity gap in participation, this underrepresentation reflects broader issues of epistemic and representational justice, raising questions about whose knowledge is validated and whose voices are legitimized in scientific spaces. This study examines how Pacific university bridge programs support Indigenous islander participation in authentic STEM research, with particular focus on climate adaptation, environmental change, and marine science contexts. Through qualitative interviews with Micronesian participants in the SEAS (Supporting Emerging Aquatic Scientists) Islands Alliance, we analyzed STEM identity development as students navigated cultural and scientific identities. Findings emphasize the critical importance of sustained, mentored engagement in real-world scientific inquiry that meaningfully connects to ongoing research agendas and community well-being, rather than simulated classroom exercises. The study offers insights into the multifaceted influences affecting student participation and pathways through STEM. Full article

This work presents an automated method for detecting and monitoring volcanic islands in the Tonga archipelago using Sentinel-2 satellite imagery. The method is able to detect newly created islands, as well as an increase in island size, a possible precursor to an explosion due to magma chamber inflation. At its core, the method combines a U-Net-type convolutional neural network (CNN) for semantic segmentation with a custom change detection algorithm, enabling the identification of land–water boundaries and the tracking of volcanic island dynamics. The algorithm analyzes morphological changes through image comparison and Intersection over Union (IoU), capturing the emergence, disappearance, and evolution of volcanic islands. The segmentation model, trained on a custom dataset of Pacific Ocean imagery, achieved an IoU score of 97.36% on the primary test dataset and 83.54% on a subset of challenging cases involving small, recently formed volcanic islands. Generalization capability was validated using the SNOWED dataset, where the segmentation model attained an IoU of 81.02%. Applied to recent volcanic events, the workflow successfully detected changes in island morphology and provided time-series analyses. Practical feasibility of the methodology was assessed by testing it on a large region in Tonga, using an HPC cluster. This system offers potential applications for geophysical studies and navigation safety in volcanically active regions. Full article

Understanding the spatial and temporal structure of crustal deformation is essential for identifying tectonic blocks, assessing seismic hazard, and detecting precursory deformation associated with major megathrust earthquakes. In this study, we analyze twenty years of continuous GNSS observations from the Japanese Islands to identify coherent deformation domains and anomalous regions using an integrated time-dependent clustering framework. The workflow combines six machine learning algorithms (Hierarchical Agglomerative Clustering, K-means, Gaussian Mixture Models, Spectral Clustering, HDBSCAN and consensus clustering) and constructs a set of deformation-related features including steady-state velocities, strain rates, co-seismic and post-seismic displacements, and spatial distance metrics. Optimal cluster numbers are determined by validity metrics, and the most robust segmentation is obtained using a consensus approach. The resulting spatiotemporal domains reveal clear segmentation associated with major geological structures such as the Fossa Magna graben, the Median Tectonic Line, and deformation belts related to Pacific Plate subduction. The method also highlights deformation patterns potentially associated with the preparation stages of megathrust earthquakes. Our results demonstrate that machine learning-based clustering of long-term GNSS time series provides a powerful data-driven tool for quantifying deformation heterogeneity and improving the understanding of active geodynamic processes in subduction zones. Full article

During the 71st cruise of the R/V Akademik Oparin in the summer of 2024, we assessed the distributions of dissolved and particulate forms of ²¹⁰Pb and ²¹⁰Po in the Sea of Japan, the Sea of Okhotsk, and the northwestern Pacific Ocean. Quantitative estimates of vertical fluxes were derived based on measured concentrations of suspended particulate matter (SPM) and particulate organic carbon (POC). This study provides the first in situ measurements of these radionuclides and the first estimates of derived fluxes for the Sea of Okhotsk. The study confirmed the existence of two contrasting biogeochemical regimes: a sedimentation regime in the productive waters of the Sea of Okhotsk and a recycling regime in the oligotrophic waters of the open ocean, separated by the dynamic transition zone of the Kuril Islands. The calculated POC fluxes confirmed the high efficiency of the biological pump in the coastal seas. The identified anomalies in the distribution of radionuclides indicate a significant role of lateral transport and the sorption of organic carbon onto mineral particles in shaping vertical fluxes matter. Full article

We describe two new species of Paradraconema from subtidal sediments of Korean waters: P. tamraense sp. nov. from Jeju Island and P. gangchii sp. nov. from Dokdo Island. Although the epithet tamraense had appeared previously in the literature, it was treated as a nomen nudum and therefore lacked nomenclatural availability under the ICZN. In this study, the species is newly and validly established based on a critical reassessment of the original material, supported by new line drawings and detailed observations using differential interference contrast (DIC) and scanning electron microscopy (SEM). Paradraconema amraense sp. nov. is characterized by a slender body; pharyngeal annules bearing weakly developed longitudinal bars with smooth margins; a narrow lateral field at midbody; abundant and relatively long somatic setae; a head capsule partially covered with vacuolated ornamentation; an amphidial fovea that is elongate loop-shaped in males and circular, unispiral in females; eleven cephalic adhesion tubes (CAT); and comparatively long sublateral adhesion tubes (SlAT) and subventral adhesion tubes (SvAT). Paradraconema gangchii sp. nov. is characterized by a slender body; cuticle ornamentation with numerous longitudinal bars bearing finely crenulated margins in the pharyngeal region; sparse and short somatic setae; a head capsule fully covered with vacuolar ornamentation (reticulate under SEM); an amphidial fovea that is elongate loop-shaped in males and circular, unispiral, slightly over one coil in females; relatively short spicules (36–46 µm); eleven CAT; and relatively short SlAT and SvAT. SEM revealed several fine morphological features not previously documented in the genus, including the precise number and arrangement of CAT and detailed structures of the cuticle ornamentation and lip region. This study provides comprehensive SEM-based documentation for Paradraconema, increases the number of valid species in the genus to thirteen, and enhances our understanding of draconematid diversity in the northwestern Pacific. Full article