Freshwater ecosystems are currently facing a biodiversity crisis. The decline in freshwater fish populations, particularly in alpine streams, is exacerbated by environmental changes such as climate change, habitat fragmentation, and human activities. In this context, monitoring freshwater fish populations is complex, especially in winter conditions with snow cover when traditional methods, such as electrofishing, become difficult. This pilot study explores the use of remote underwater video (RUV) systems for monitoring salmonids in winter conditions in the Torrente Vallanta, an alpine stream in North-West Italy. By using 28 deployments and a total effort of 8.97 hours, our results demonstrate that RUV technology is effective for detecting the presence of salmonids, estimating the size and observing their behaviour in remote streams. The detectability of salmonids varied across different segments of the stream and RUV technology provided valuable insights into winter fish behaviour, such as limited movement and the search for hideouts. This study sets the foundation for future research on fish assemblages in poorly studied streams in the Alps, providing an important tool for conservation efforts in the context of the freshwater biodiversity crisis.

Mangrove forests are multifunctional coastal ecosystems that support biodiversity and a variety of ecosystem services, including fisheries productivity, coastal stability, climate change mitigation, and pollution control. Despite growing scientific awareness of these benefits, mangrove loss continues, mainly due to urban development and the expansion of aquaculture. International governance of mangroves is fragmented, contributing to uneven and insufficient protection. The main global legal and policy instruments related to mangrove conservation and restoration address mangroves through partially overlapping but often uncoordinated objectives, leading to implementation that rarely reflects mangroves as integrated land-sea systems. Rather than promoting a new treaty, a practical defragmentation strategy based on integrated interpretation and coordinated implementation of existing frameworks is needed. More rigorous integration of mangroves into nationally determined contributions under the Paris Agreement with ecological and social safeguards is needed, coupled with clearer operationalisation of due diligence obligations under the United Nations Convention on the Law of the Sea to support coherent coastal protection. Effective governance must also incorporate scientific considerations essential for lasting results, including preventing further loss of mangrove forests, avoiding inappropriate restoration, maintaining connectivity between river basins and coasts, anticipating climate-induced habitat changes, and resolving financial and capacity limitations.

Alpine streams represent some of the most challenging yet ecologically valuable freshwater environments to study, due to their remoteness, fast flows, and extreme climatic conditions. Traditional fish survey methods are often impractical or invasive in these habitats. This study presents a lightweight, low-cost, T-shaped Remote Underwater Video (RUV) system optimised for fish monitoring in small, high-altitude streams of the European Alps. Field tests were conducted across three alpine streams in northwestern Italy in June 2025. The RUV system proved effective in recording salmonid presence, estimating fish length using an integrated reference scale, and capturing natural behaviours such as feeding. The compact steel frame (~1 kg) ensured stability in fast-flowing waters while remaining portable for deployment in remote areas. Despite challenges such as bubble interference and site accessibility, the RUV allowed reliable, permanently-recorded observations with minimal disturbance. This method offers a promising non-invasive approach for ecological research and conservation monitoring in alpine freshwater systems, with potential applications in species distribution studies and behavioural ecology.