Natural Environment Research Council

Surface melting and runoff account for about half of the current mass loss of the Greenland Ice Sheet. Regional climate models (RCMs) project runoff to increase further over the 21st century, but the magnitude of this trend varies strongly between different models. This variability arises because RCMs rely on simplified representations of the complex firn hydrological system in Greenland’s percolation zone. However, key parameters for parametrizing meltwater retention and runoff processes remain poorly constrained due to a lack of time-resolved, in situ observations of firn liquid water content.We address this gap by demonstrating that the Autonomous phase-sensitive Radio-Echo Sounder (ApRES) can continuously trace the amount of liquid water in the firn. At three automatic weather station sites on the ice sheet (KAN_U, DYE-2 and Camp Century), we acquired hourly ApRES time series between spring 2023 and 2025, covering two melt seasons. By analyzing these observations in combination with a firn model, we quantify rates of lateral meltwater flow. Comparison with runoff simulations from three RCMs shows that all models overestimate local runoff at KAN_U, and that some even predict runoff at DYE-2 (2124 m a.s.l.), where our observations indicate that all meltwater is refrozen. Expanding these observations will support the development of improved representations of Greenland’s firn hydrological system in RCMs and ultimately enhance the accuracy of GrIS mass balance projections.

Ocean warming affects ectotherm physiological and phenological processes, potentially creating mismatches between early life stages and their prey. Seasonal spawning cohorts are thought to provide flexibility in responding to environmental variability, but if there is seasonal adaptation between these cohorts, then they may respond to ocean warming differently, affecting species resilience and potentially impacting the wider food web. We tested the response to warming of egg masses and paralarvae from two spawning cohorts (autumn and spring) of the Patagonian squid (Doryteuthis gahi). Treated egg masses were exposed to a strict warming regime while control eggs were exposed to air temperature-driven temperature changes. Egg mass respiration estimates demonstrated that higher temperatures resulted in higher respiration rates (metabolic processes), although no additional influence of the rate and magnitude of warming was detected. There were differences in paralarvae size and weight, with the treated autumn cohort containing smaller and lighter paralarvae, which could affect larval duration, especially if early hatching times and smaller hatchlings cause mismatches with their prey or increased predation. This suggests that temperature could influence survival and recruitment success. Greater understanding is required of how temperature changes influence squid phenology (e.g., from timing of egg laying to paralarvae growth and survival) and its likely influence on biomass at adult feeding grounds, which are also important fishing grounds. Further targeted studies could improve the prediction of future impacts on marine food webs, indicating if, for example, changing the timing of fishing seasons, in response to environmental cues would be a useful climate adaptation strategy for the Falkland Islands.

Comprehending a species' life-history strategies is crucial to inform effective conservation efforts. Commercial fishing impacts icefish (family: Channichthyidae) in the Scotia Sea, but detailed information on species-specific life histories remains largely unknown. In this study, the demographic characteristics of mackerel icefish (Champsocephalus gunnari), blackfin icefish (Chaenocephalus aceratus) and South Georgia icefish (Pseudochaenichthys georgianus) were examined and used to compare inferred life-history strategies, using long-term data from demersal and plankton trawl surveys conducted across the South Georgia and the Shag Rocks continental shelves. The results indicated that C. gunnari may exhibit alternative reproductive tactics, as they appear to spawn multiple times in a single year and mature at varying sizes. Conversely, C. aceratus and P. georgianus reproduced once per annum and appeared to favour investing in somatic growth, resulting in them consistently maturing at a larger size. Seasonal sex ratios demonstrated a reduction in captured mature males for C. aceratus and P. georgianus during the suspected spawning period, supporting the hypothesis of sex-specific behavioural patterns during the reproductive period. These findings highlight the variation in the life-history strategies among these three icefish species, which should be considered during the development of future management measures.

Sources of desertdust, atmospheric transport, recordedconcentrationsof atmospheric particulate matter (PM), physical, compositional, andbiological characteristics, and likely direct and indirect impactson air quality impairment are reviewed without a systematic, but withan expert approach. The aim is to offer information necessary to protectthe health of exposed populations in the dust-emitting and dust-receptorregions. This review corroborates the complexity of the process bywhich air quality is impaired during dust episodes, the mixture ofcomponents that PM might contain during dust episodes, the differencesbetween dust emission and reception regions, and the interplay ofindirect effects (thinning the boundary layer; concentration of localpollution; interactions with anthropogenic pollutants). Based on thesedust episode patterns, we recommend the implementation of alert systemsto protect the more vulnerable members of the population and highlighta number of recommendations for air quality monitoring during suchepisodes to provide adequate data sets to rigorously evaluate healthoutcomes associated with dust exposure in emitting and receptor regionsand the possible causes for these effects.

Data sharing not applicable to this article as no datasets were generated or analysed during the current study.

Abstract This study investigated soil organic carbon (SOC) pools and soil microbial biomass carbon (SMBC) across three forest types in Mizoram, India: Secondary Moist Bamboo Brakes, East Himalayan Moist Mixed Deciduous Forest, and Cachar Tropical Semi-Evergreen Forest. SOC is crucial for global biogeochemical cycles, influencing nutrient availability and ecosystem resilience. The study highlights the impact of forest type on SOC dynamics and microbial activity. The Secondary Moist Bamboo Brakes exhibited an Active Pool (VLC + LC) of 1.21% and a Passive Pool (LLC + NLC) of 0.78%, with SOC of 1.58% and SMBC of 340.72 mg/kg, indicating a balanced microbial presence. The East Himalayan Moist Mixed Deciduous Forest had relatively higher SOC (2.49%) and SMBC (352.31 mg/kg), suggesting increased microbial activity and faster carbon turnover. The Cachar Tropical Semi-Evergreen Forest recorded the highest SOC (2.51%) and significant SMBC (348.73 mg/kg), with the highest Very Labile Carbon (VLC) at 1.06%. Dehydrogenase activity (DHA), a key indicator of microbial metabolic activity, was highest in the East Himalayan Moist Mixed Deciduous Forest (6.42 µg TPF/g/h) and lowest in the Secondary Moist Bamboo Brakes (5.62 µg TPF/g/h). Correlations between SMBC and SOC pools were weak, with VLC and LC showing significant positive relationships with TOC (r = 0.636 and 0.693). These findings underscore the importance of forest type in shaping SOC and microbial dynamics, with implications for sustainable land management and carbon sequestration strategies in tropical forests.

Background: Breeding pelagic seabirds feed over wide areas. Their diet and space use can therefore provide proxies for otherwise be difficult to observe environmental conditions but interpretation of these proxies requires knowledge of foraging range. Antarctic sea ice regulates global climate, but a paucity of data on its past extent causes uncertainty in climate reconstruction and prediction. Deposits of stomach oils, produced defensively by snow petrels Pagodroma nivea (near-obligate sea-ice foragers), reflect sea ice conditions, sometimes over tens of millennia, but spatial interpretation of these biological archives is hampered by lack of data on foraging range, and how this varies seasonally, among colonies and with sex. Methods: We tracked 34 and 60 snow petrels using light-based geolocators and GPS loggers, respectively to estimate foraging ranges at three colonies located 180-200 km inland in Dronning Maud Land. We tested whether foraging latitude is associated with ice edge latitude, estimated via satellite remote sensing. We then projected potential foraging ranges for all known colonies on the study area to reexamine assumptions made in paleoclimate studies. Results: During most breeding stages, and across breeding seasons, core home ranges were centred approximately 2 degrees south of the outer sea-ice edge and tracked this habitat as it receded during the spring melt. Females were approximately 7% lighter than males but foraged at similar distances and in similar areas. Foraging ranges differed little between colonies but substantially between breeding stages. For example, median range was ~1,400 km during the pre-laying exodus vs. ~550 km during brood-guard. Conclusions: Snow petrel stomach-oil deposits potentially integrate environmental conditions over greater and more seasonally variable areas than previously assumed, probably with a bias towards conditions in the outer Marginal Ice Zone during the early summer when stomach oil deposition due to nest competition is likely greatest. Projected potential home ranges of snow petrel colonies in the western Weddell Sea suggest that breeding is limited by access to foraging habitat, such as coastal polynyas. We hypothesise that as sea ice fluctuated over previous glacial-interglacial cycles, this also regulated breeding distribution across the region.

Climate change and resource exploitation in the Southern Ocean are important anthropogenic pressures on Antarctic food webs. Understanding the eco-functional roles of Antarctic communities is essential for ecosystem management and conservation. Amphipods are among the most dominant and ecologically important benthic taxa in the Southern Ocean. The amphipod genus Charcotia is part of the scavenger guild playing a dominant role in nutrient recycling. To study the trophic habits of two sister species C. amundseni and C. obesa, stable isotope ratios of carbon and nitrogen were measured along geographical and bathymetrical gradients. Charcotia obesa belongs to the fourth and C. amundseni to the fifth trophic level, based on significant differences in δ15N values. Both benthic and pelagic primary producers dominate the diet in both species as derived from their low δ13C values. Charcotia obesa, the species with the narrowest depth range of the two studied species, did not show a depth-related pattern in isotopic ratios. An increasing geographic gradient of both δ15N and δ13C values was observed for C. obesa, ranging from the northern most tip of the Western Antarctic Peninsula to the southwestern most part in the Bellingshausen Sea. This might be linked to nutrient rich glacial meltwater in the latter part of the Southern Ocean. Nitrogen stable isotope ratios of C. amundseni showed a significant difference between Crown Bay and the other locations; this might be explained by the close location of the Filchner Area to nutrient rich upwelling in the Weddell Sea Gyre. Our study provides evidence for niche differentiation between two closely related amphipod species. Incorporation of additional samples from other locations and depth ranges in combination with isotope analysis and DNA-based prey identification might clarify the trophic position of benthic amphipods.

With biodiversity loss escalating globally, a step change is needed in our capacity to accurately monitor species populations across ecosystems. Robotic and autonomous systems (RAS) offer technological solutions that may substantially advance terrestrial biodiversity monitoring, but this potential is yet to be considered systematically. We used a modified Delphi technique to synthesize knowledge from 98 biodiversity experts and 31 RAS experts, who identified the major methodological barriers that currently hinder monitoring, and explored the opportunities and challenges that RAS offer in overcoming these barriers. Biodiversity experts identified four barrier categories: site access, species and individual identification, data handling and storage, and power and network availability. Robotics experts highlighted technologies that could overcome these barriers and identified the developments needed to facilitate RAS-based autonomous biodiversity monitoring. Some existing RAS could be optimized relatively easily to survey species but would require development to be suitable for monitoring of more ‘difficult’ taxa and robust enough to work under uncontrolled conditions within ecosystems. Other nascent technologies (for instance, new sensors and biodegradable robots) need accelerated research. Overall, it was felt that RAS could lead to major progress in monitoring of terrestrial biodiversity by supplementing rather than supplanting existing methods. Transdisciplinarity needs to be fostered between biodiversity and RAS experts so that future ideas and technologies can be codeveloped effectively.