The Arctic is undergoing rapid and spatially heterogeneous warming, with Svalbard among the fastest-changing regions worldwide. These transformations are reshaping coastal ecosystems and marine vertebrate communities, yet biodiversity assessments remain limited by logistical constraints and protection regulations. Environmental DNA (eDNA) metabarcoding offers a non-invasive alternative capable of capturing taxonomic and phylogenetic diversity across habitats. Here, we surveyed marine vertebrates along the western coast of Svalbard using continuous seawater filtration (16 transects of 2.5 miles each) from a dedicated sailing vessel, covering glacier fronts, walrus haul-out sites, harbors, and both shallow and deep-water areas. Across 31 samples collected at 16 sites, we detected 36 taxa, including 19 fish, 8 mammals, 8 birds, and 1 elasmobranch species. The congruence between eDNA, visual observations, and acoustic detections confirms the feasibility and robustness of eDNA sampling under Arctic conditions. Contrary to expectations of homogeneous assemblages across nearby sites, we observed marked taxonomic and phylogenetic turnover among habitats. Harbors and walrus haul-out areas showed particularly high taxonomic richness and phylogenetic diversity, whereas glacier-influenced sites were dominated by a few closely related taxa, suggesting that local conditions constrain community composition. Several detections, including Gasterosteus aculeatus, increased Phoca vitulina occurrence, and widespread Branta leucopsis, are consistent with biogeographic shifts linked to Arctic warming. The identification of Red List species and elusive taxa further illustrates the sensitivity of eDNA for conservation-focused monitoring. Overall, this study establishes eDNA metabarcoding as an effective tool for characterizing Arctic marine vertebrate communities and provides a valuable baseline for tracking ecological responses to rapid environmental change.
The ongoing biodiversity crisis, often referred to as the ‘sixth mass extinction’, is driven by anthropogenic pressures and is causing unprecedented species loss. Invasive alien species, a major threat to terrestrial biodiversity, can exploit ecological niches and disrupt trophic interactions in tropical island forests. However, data on terrestrial communities in these systems remain scarce. We used camera traps to characterize the ground-dwelling faunal assemblages of the tropical forests of Guadeloupe, a Caribbean island hosting several bird and mammal species, including domestic cats, dogs, raccoons and mongooses. We studied the spatial distribution and relative abundance of exotic species and assessed the influence of biotic and abiotic factors on their abundance and distribution. Several native and endemic birds were detected, including Geotrygon mystacea, endemic to the Caribbean; Turdus lherminieri, restricted to four Lesser Antillean islands; and Melanerpes herminieri, endemic to Guadeloupe. Among the mammals recorded, all were invasive species, including Rattus spp., Urva auropunctata, Procyon lotor, Felis catus and Canis lupus familiaris. Despite the diversity of terrestrial assemblages, invasive species, particularly rats and the small Indian mongoose, dominated all forest types. Cluster analysis identified six distinct communities, primarily structured by elevation and temperature. The most species-rich communities were dominated by invasive mammals, particularly rats and mongooses. These findings highlight the need to prioritize invasive mammal control, strengthen long-term ecological monitoring, and improve coordinated management actions to protect native and endemic forest vertebrates in Guadeloupe and across the Caribbean.
We present a threshold-based multiscale framework that links mechanistic within-host infection dynamics to a structured, SIR-like population model. Starting from a two-variable system for pathogen load and immune response that includes inoculum (Allee-like) thresholds and nonlinear immune activation, we derive mapping rules that classify continuous trajectories into four states: susceptible (S), infected with low immune protection ( I^- ), infected with high immune protection ( I^+ ), and recovered (R). Here, “infected” refers to individuals with a detectable pathogen load. Unlike previous multiscale approaches, our framework integrates both scales into a single system: population compartments emerge by direct projection of within-host trajectories, avoiding ad hoc linking functions. We derive a next-generation operator for trait-structured re-exposure (local vs. global mixing) and an explicit expression for ℛ_0 under global mixing. Simulations reveal sharp clearance–persistence transitions driven by inoculum size and immune trait, and an emergent S→I^-→I^+→R cascade. Under sharp thresholds and activation, chronic within-host equilibria can sustain infection even when ℛ_0<1 , producing backward-bifurcation-like behavior at the population level. The framework provides a consistent route from immunological heterogeneity to epidemic indicators, with implications for identifying chronic reservoirs, interpreting dose-response data, and estimating control thresholds directly from within-host measurements.
A bstract Wild silkmoths (Saturniidae) are one of the most emblematic and most studied families of moths. Yet, the absence of a robust phylogenetic framework based on a comprehensive taxonomic sampling impedes our understanding of their evolutionary history. We analyzed 1,024 ultraconserved elements (UCEs) and their flanking regions to infer the relationships among 338 species of Saturniidae representing all described subfamilies, tribes, and genera. We investigated systematic biases in genomic data and performed dating and historical biogeographic analyses to reconstruct the evolutionary history of wild silkmoths in space and time. Using Gene Genealogy Interrogation, we showed that saturation of nucleotide sequence data blurred our understanding of early divergences and first biogeographic events. Our analyses support a Neotropical origin of saturniids, shortly after the Cretaceous-Paleogene extinction event ( ca 64.0 [stem] - 52.0 [crown] Ma), and two independent colonization events of the Old World during the Eocene, presumably through the Bering Land Bridge. Early divergences strongly shaped the distribution of extant subfamilies as they showed very limited mobility across biogeographical regions, except for Saturniinae, a subfamily now present on all continents but Antarctica. Overall, our results provide a framework for in-depth investigations into the spatial and temporal dynamics of all saturniid lineages and for the integration of their evolutionary history into further global studies of biodiversity and conservation. Rather unexpectedly for a taxonomically well-known family such as Saturniidae, the proper alignment of taxonomic divisions and ranks with our phylogenetic results leads us to propose substantial rearrangements of the family classification, including the description of one new subfamily and two new tribes.
The botanical origin of honey strongly influences its chemical composition and bioactive properties, making authentication essential for quality assurance and consumer trust. Conventional methods, such as physicochemical and chromatographic analyses, are accurate but often time-consuming and require sophisticated instrumentation. This study proposes an integrated approach combining electrochemical fingerprinting with established techniques to deliver a rapid, cost-effective, and reliable strategy for honey authentication. Two tropical honeys with distinct botanical origins, including a monofloral Ziziphus mauritiana honey and a Haematoxylum campechianum-rich multifloral honey were characterized using Fourier-transform infrared spectroscopy (FTIR), high-performance liquid chromatography (HPLC), Karl Fischer titration, and cyclic voltammetry (CV). FTIR provided general compositional profiles, while HPLC and Karl Fischer revealed significant differences in sugar and moisture content. CV generated distinct electrochemical signatures, enabling clear discrimination of botanical origin and reflecting variations in reducing sugars and minor redox-active compounds. These findings highlight the potential of voltammetric analysis as a complementary tool to conventional and melissopalynological methods for honey authentication and traceability. We recommend this integrated approach to enhance regulatory compliance and food integrity, particularly in regions with limited access to advanced analytical resources.
