Studying social behaviour of mobile and cryptic marine mammals is challenging, particularly for small species like harbour porpoises whom in many areas tend to be challenging to initially spot and then gain repeated observations. Recently, there has been a rise in the number of observations of harbour porpoises occurring in atypical group sizes that are larger than the typical size of two to three individuals. This behaviour, in conjunction with the evolving availability and usability of Unmanned Aerial Vehicle (UAV) technology, is supporting and improving the capture of information on social behaviours. Around Shetland, Scotland, harbour porpoises are sighted from land via opportunistic and systematic surveys year-round with atypical group sizes also observed. To capture information on group size, opportunistic and systematically collected UAV footage were collated and analysed. This revealed sexual approach behaviours in typical group sizes of small groups (two to four individuals), as well as atypical group sizes of medium groups (five to nine individuals), large groups (10 to 19 individuals), and aggregations (≥20 individuals) occur in multiple bays around Shetland. This is the first insight into group sizes and behaviours for the region which was recently designated as an Important Marine Mammal Area (IMMA). Further insight into these social behaviours and group size (e.g. seasonality, site fidelity) could aid harbour porpoise conservation and management within the IMMA and elsewhere.

The suitability of marine limpet shells for radiocarbon dating may depend on potential offsets due to diet and habitat, especially with regard to grazing mollusks on carbonate substrates (Dye 1994; England et al. 2013). A previous study on one grazing limpet species on the coast of Ireland found no offsets from carbonate substrates (Allen et al. 2019), but a similar study from mediterranean coasts found significant offsets on carbonate substrates (Ferguson et al. 2011). We carried out a new study of radiocarbon and stable carbon isotopes, using multiple species of mollusks collected live from the coasts of Gibraltar and Sardinia, from both carbonate and non-carbonate substrates. The 14C results indicate that one species, inhabiting the upper shore, has a significant offset at the carbonate locations. This species, Patella rustica, has adapted to tolerate desiccation and may have biological traits that result in higher metabolic-derived carbon incorporated in its shell. The results of this preliminary study imply that selected species of grazing mollusks are suitable for radiocarbon dating, even in areas of carbonate geology.

Radiocarbon dating by accelerator mass spectrometry (AMS) requires transforming samples into graphite, a step that typically depends on liquid nitrogen and high-purity carrier gases, increasing both cost and operational complexity. We present μGRAPHILINE, a fully automated, modular combustion–graphitization line that removes these dependencies by combining dual-zone combustion with iron–zinc reduction. Performance was evaluated on more than 180 standards and reference materials targets measured on two independent AMS systems. The μGRAPHILINE consistently achieved >90% graphitization yields, stable backgrounds of ∼0.24 pMC (≈48,500 BP), and sample throughput of ∼3.5 hours per target. Reliable operation was demonstrated for a broad sample-size range, from routine 1 mg C down to ∼0.2 mg C, with ion currents sufficient for precise AMS analysis. The system’s automation, modularity, and low memory effect support improved laboratory throughput and operator efficiency. These results indicate that μGRAPHILINE provides a robust and efficient approach to radiocarbon sample preparation with broad potential applications.

Welwitschia mirabilis, a unique gymnosperm native to Namibia and Angola, is a keystone plant species in the Namib Desert. It represents the only extremely long-lived non-clonal plant species occurring under hyperarid desert conditions, yet limited attempts have been made to accurately determine its age. Here, we present radiocarbon dates from a dead, sectioned Welwitschia of moderate size. We find the outer caudex tissue growth to progressively increase in age from the leaf base towards the ground level in this dwarf tree, while the inner cortex tissue becomes younger. Our sampling strategy revealed that the oldest tissue from this Welwitschia, found at the base of the caudex in the middle of the lobe, was dated to 531 ± 20 14C years, suggesting a vertical growth rate of approximately 0.47 to 0.67 mm/year. These findings can serve as a basis for future dating of larger, living individuals.

We investigated the epizoic diatoms colonizing the carapace of the spider crab Hyastenus hilgendorfi inhabiting Lake Timsah in the Suez Canal. A total of 63 individuals, free of macro-epibionts, were examined to assess the diversity, abundance, and seasonal dynamics of their associated diatom communities. A total of 61 diatom taxa belonging to 31 genera were recorded, with raphid pennate diatoms being the most dominant, particularly Navicula lanceolata. Diatom density and diversity exhibited clear seasonal variation, where Summer had the highest richness and Spring the highest cell densities. Overall, males hosted more diatom taxa than females, however, sex-specific differences fluctuated seasonally. The cluster analysis revealed distinct diatom assemblages between sexes and seasons, showing subtle but significant variation in epibiont structure. These findings provide the first detailed characterization of epizoic diatom assemblages on H. hilgendorfi. They suggest that seasonal variations in diatom communities may influence the crab’s camouflage effectiveness by altering biofilm characteristics which facilitate macro-epibiont settlement.

Monitoring snow distribution in alpine terrain is critical for hydrology, avalanche safety, and climate research, yet traditional surveys are costly, hazardous, and spatially sparse. We assess a gondola-mounted, low-cost Light Detection and Ranging (lidar) system (MOLISENS) for repeated snow monitoring in Real-Time Kinematics (RTK)-denied mountain environments. The system fuses lidar, Inertial Measurement Unit (IMU), and standalone Global Navigation Satellite System (GNSS) using a Simultaneous Localization And Mapping (SLAM) algorithm to generate 3D point clouds along a fixed aerial-lift transect at Hoher Sonnblick, Austria. Six winter runs (March 2023) were processed and compared with summer Unmanned Aircraft System (UAS)-photogrammetry. Intra-system repeatability between same-day scans reached centimetre precision (weighted standard deviation 0.010 m; 95% within $\pm$0.006 m), supporting detection of daily to seasonal changes in snow thickness along the route. Absolute agreement with the UAS reference was limited to decimetre scale, primarily due to registration and standalone GNSS uncertainties rather than sensor range noise. Performance degraded over feature-poor snowfields, and manual segment merging was labor-intensive; consequently, quantitative analyses were restricted to well-constrained segments. Despite these limitations, the results demonstrate the feasibility of gondola-mounted lidar for cost-effective, repeatable snow-thickness mapping.

This study provides the first results on the population dynamics of Sphyraena sphyraena (Linnaeus, 1758) in the western Mediterranean. Otoliths and scales reading were used for its age and growth investigation in Eastern coast of Algeria. The monthly evolution in marginal increment data of scales and otoliths revealed that only one annulus is formed per year in February. Fish length and radii of the scales or otoliths were closely correlated. Both methods showed four age groups. ANOVA test (P < 0.05) revealed insignificant differences between both estimates of length at age results. Growth parameters estimated using length-at-age data from both methods confirming the age determination results. The total mortality (Z ), natural mortality (M ), and fishing mortality (F ) were estimated at 1.19 year−1, 0.826 year−1, and 0.363 year−1, respectively. The growth performance index (Ø ) was 2.57. The estimated exploitation ratio (E ) was 0.305. The length–weight relationship is EW = 0.0104 TL2.702, showed that the growth rates were negative allometric. The results revealed the compatibility of otoliths and scales reading for assessment studies of Sphyraena sphyraena .

In Brazil, laws are being adopted prohibiting the use and distribution of non-recyclable plastic bags and encouraging the use of recyclable, biodegradable and bioplastic bags. However, there is no specific standard method in Brazil to inspect the carbon content of bioplastics. This work aims to implement the sample preparation for radiocarbon biogenic fraction determination in bioplastics in the new radiocarbon laboratory at the Federal University of Bahia (LAPA14C-UFBA). Six plastic samples from Brazilian markets with bio-based seals were collected in regular Brazilian markets, four bags and two tubes. All samples were combusted and graphitized in the LAPA14C-UFBA and the graphites were measured at the Radiocarbon Laboratory (LAC-UFF). The biogenic fraction analysis followed the Standard Test Methods for Determining the Biobased Content of Solid, Liquid, and Gaseous Samples Using Radiocarbon Analysis (ASTM D6866-24). Since the bioplastic manufactured in Brazil is derived from sugarcane, a C4 plant where δ13C values are different from those of petroleum-derived plastic, the biogenic fraction was obtained via the isotopic mixture equation. The results showed a robust direct correlation (r=0.998) between the fractions obtained by the two methods, indicating that δ13C analysis can be used, in this case, as an alternative in determining the biogenic fraction of plastics. From the results obtained, four out of the six samples analyzed showed biogenic fraction values below the 51% required by the I’m Green label, with values ranging from 4% to 43%, according to the δ3C and 14C analysis, showing the efficiency of both techniques in determining the biogenic fraction.

Rare Earth Elements (REEs) are essential for green energy technologies and defense systems, yet global supply chains remain concentrated in China. This has intensified geopolitical competition for alternative sources, positioning the Arctic as a strategic frontier, as retreating ice exposes mineral deposits. A comprehensive discourse analysis of strategic documents, scholarly literature, and media sources from 2010 to 2025 reveals a dramatic shift from geological characterization and economic speculation to urgent securitization and strategic alliance formation. Academic research has evolved from establishing natural baselines to governance and social conflict analysis. Media coverage of REE in the Arctic peaked in 2025, with rising emphasis on governance, sovereignty, geopolitics, and Greenland’s strategic position. Critical gaps persist in addressing Indigenous rights, holistic impact assessments, and Arctic-specific innovation. Sustainable Arctic REE development requires integrated frameworks that balance geopolitical imperatives with environmental protection and Indigenous self-determination, preventing the region from becoming a sacrifice zone for global decarbonization.

The annelid genus Diopatra is a well-known example of marine ecosystem engineering, as it creates tubes in coastal sediments all around the world. In the Amazon coast, this annelid is common in intertidal estuarine areas and protected beaches. However, there are no data for the Amazon coast regarding studies on the meiofauna associated with Diopatra sp. tubes. Therefore, the present study characterized, for the first time, the meiofauna community found on a muddy-sandy tidal flat of the Amazon coast in areas with and without the presence of Diopatra sp. tubes. Samples were collected in February 2014 in two different areas: (1) an area in which Diopatra sp. tubes were present, and (2) an area without tubes. A total of 13 major meiofaunal groups were found, with Nematoda as the dominant group. Overall, a significant increase in meiofauna density and richness of the meiofauna was observed in the area with the presence of Diopatra sp. tubes. While no large aggregations of Diopatra sp. tubes were observed in the study region, the presence of even a single tube had significant effects on the environmental conditions available to the meiofauna community. The present findings add knowledge about the presence of the bioconstructor in coastal areas and reinforce the role of tube-building polychaetes as ecosystem engineers.

This study presents a framework that combines Bayesian inference with reinforcement learning to guide drone-based sampling for methane source estimation. Synthetic gas concentration and wind observations are generated using a calibrated model derived from real-world drone measurements, providing a more representative testbed that captures atmospheric boundary layer variability. We compare three path planning strategies—preplanned, myopic (short-sighted), and non-myopic (long-term)—and find that non-myopic policies trained via deep reinforcement learning consistently yield more precise and accurate estimates of both source location and emission rate. We further investigate centralized multi-agent collaboration and observe comparable performance to independent agents in the tested single-source scenario. Our results suggest that effective source term estimation depends on correctly identifying the plume and obtaining low-noise concentration measurements within it. Precise localization further requires sampling in close proximity to the source, including slightly upwind. In more complex environments with multiple emission sources, multi-agent systems may offer advantages by enabling individual drones to specialize in tracking distinct plumes. These findings support the development of intelligent, data-driven sampling strategies for drone-based environmental monitoring, with potential applications in climate monitoring, emission inventories, and regulatory compliance.