United Nations Environment Programme

Artisanal and small-scale gold mining (ASGM) mobilizes metal-rich sediments and trace contaminants into river systems, creating ecological and toxicological risks in tropical catchments. Distinguishing mining-derived contamination from natural hydrogeochemical variability remains difficult in data-poor regions with strong seasonal sediment transport. Here, we combined monthly community-based water-quality observations, laboratory ICP-MS measurements, and Bayesian multivariate hierarchical modelling to quantify the relative influence of basin hydrogeochemistry, seasonal hydrology, and mining activity on river metal assemblages in two Sierra Leone basins with contrasting degrees of ASGM impact.Metal variability was dominated by basin-scale hydrogeochemical controls and particle-associated transport, while mining-affected catchments showed additional enrichment in Mn, Co, Ni, Cr, and Pb, elements of potential toxicological concern for aquatic ecosystems and downstream water users. Seasonal hydrology modulated concentrations but did not obscure the mining signal. The probabilistic modelling framework separated natural and anthropogenic controls while accounting for metal covariance and uncertainty in environmental effects.Low-cost multi-metal colorimetric kits were unreliable for detecting mining gradients, whereas community-led turbidity measurements provided an operational proxy for sediment-associated disturbance. These results support a tiered monitoring strategy combining frequent community turbidity observations with targeted laboratory analyses of Mn, Co, Ni, Cr, and Pb to identify contamination hotspots of potential ecological and exposure concern. The approach provides an adaptable early-warning framework for other data-limited ASGM-affected regions, though regional recalibration would be needed to account for differing geology, climate and hydrology.

A strong Community of Practice (CoP) can be powerful in supporting people to share, generate, and disseminate knowledge. This study evaluates the use of the Communities of Practice (CoP) approach for effective knowledge consolidation in the field of citizen science. Our paper offers an analysis of four CoPs that were set up as part of the European-based 3-year WeObserve project, with distinct themes of (1) co-design citizen engagement; (2) impact and value for governance; (3) interoperability and standards; and (4) the United Nations Sustainable Development Goals. Participation across the four CoPs fluctuated during their three-year life-time. Three key outcomes emerged from the CoPs. First, a joint identity and understanding were created within and across CoPs through the creation of an inception report by each CoP and through the creation of Citizen observatory (CO) vocabulary, which also served to differentiate such observatories from citizen science (CS) initiatives. Next, scientific papers and technical reports were cooperatively produced by CoP members that represent a synthesis of CoP members’ knowledge. Essential ingredients to the success of these CoPs also included extensive stakeholder engagement and the CoPs being steered by the underpinning values of the CS community. The impacts of the WeObserve CoPs range from the uptake of jointly produced publications, novel cooperative CS projects, new CoPs, joint grant proposals, and the integration of citizen science data into SDG monitoring. This evaluation highlights the diverse and transformative potential of CoPs for citizen science practice.

Recognition and engagement of Indigenous Peoples and local communities (IP&LCs) and other traditional knowledge (TK) holders in formal biodiversity governance remain limited, despite their significant contribution to the conservation and sustainable use of biodiversity through their knowledge, innovations, practices, and land stewardship. We conducted the first global assessment of how the 195 countries that ratified the Convention on Biological Diversity self-report on this contribution based on a full content analysis of all of the 2 most recent national reports (NR5 and NR6). The number of countries self-reporting IP&LC and TK roles in the conservation and sustainable use of biodiversity increased between the 2 reporting periods and exceeded 55% for NR6. The mention of IP&LC and TK contribution to cultivation and domestication was slightly higher; 59% of countries provided evidence of recognition of this contribution in their NR6. Reference to the holders themselves was much lower, even in the case of cultivation and domestication, and explicit evidence of IP&LC involvement in reporting was minimal, particularly in developed countries. Several reports, particularly European submissions, mentioned traditional land use or community-based practices but considered addressing IP&LCs and TK irrelevant due to terminology confusion. Ahead of the next reporting (NR7), due in 2026, and in line with the Kunming-Montreal Global Biodiversity Framework, which recognizes IP&LCs and TK as integral to its goals, we urge governments to strengthen engagement with IP&LCs and other TK holders, develop and respect partnerships that incorporate their knowledge, practices, and rights, support IP&LC-led conservation, and build on these partnerships in monitoring and reporting on national progress. We aimed to support this process with short-term practical recommendations for upcoming reporting and longer-term strategic guidance and a dataset of illustrative quotes from the analyzed national reports as examples of good practice.

Plume-imaging satellite instruments routinely reveal large methane point source emissions from oil and gas systems. But the observations are for instantaneous plumes, and the instruments have limited detection and revisit capabilities, making it challenging to infer time-averaged emission rates as needed for emission inventories and reporting. Here we develop a general method to infer the probability of detection (POD) of any plume-imaging instrument, over any surface, and to estimate the time-averaged point source emission rates on the basis of a limited collection of data. Applying this method to 12080 plume observations from the Sentinel-2, Landsat, EnMAP, PRISMA, EMIT, and Tanager instruments for each year in 2022-2025, we find that PODs are lower than commonly reported from controlled releases conducted under favorable conditions. We quantify annual mean emission rates for 1924 individual oil and gas point sources worldwide, estimate that point sources detected by these instruments emitted 7.6 Tg y-1 in 2025, identify 245 sources that emitted more than 1 ton h-1 on an annual basis, and show 2022-2025 trends for illustrative individual sources. 18% of sources emit for only one year and subsequently cease. Accounting for sub-detection-threshold emissions reveals higher source persistence (averaging 56%) than previously reported for oil-gas sources globally.

Biodiversity loss is a central dimension of the triple planetary crisis and underscores the need for stronger science-policy engagement to support transformative change. Early-career researchers (ECRs) can make important contributions at the biodiversity science-policy interface but often face barriers, including limited training, networks, time, resources, and institutional recognition. This Brief Report draws on insights from a two-day capacity-building workshop that brought together 20 doctoral and postdoctoral researchers from Swiss institutions and 13 experts from academia, government, and boundary organizations. The workshop aimed to strengthen participants’ understanding of science-policy processes in biodiversity conservation and to support the development of tailored engagement strategies. Based on workshop discussions, practical exercises, and expert exchange, we identify five key components of effective science-policy engagement for ECRs: understanding one’s position, analyzing the policy environment, defining engagement objectives, building networks, and reflecting on success. We argue that science-policy engagement is context-specific and requires strategic, adaptive, and sustained approaches rather than standardized solutions. Strengthening institutional support through training, mentorship, and appropriate incentives is essential to enable ECRs to engage meaningfully in biodiversity governance. Supporting ECRs at the science-policy interface can enhance both their professional development and the contribution of research to biodiversity conservation.