As rivers continue to warm due to climate change, there is an urgent need for coordinated approaches to enhance the thermal resiliency of riverscapes. Cold-water refuges (CWRs) serve as critical habitats for temperature-sensitive aquatic species, yet efforts to enhance or create these refuges often lack a unified framework, risking a fragmented and ineffective approach. To address this challenge, the authours of this study held a workshop bringing together experts, practitioners, and stakeholders to develop best practices for CWR enhancement. This manuscript synthesizes the workshop outcomes, presenting a flowchart of overarching conceptual approaches to CWR enhancement, emphasizing factors such as refuge density and type. Case study summaries highlight examples across different CWR types, providing practical insights into site-specific challenges and solutions. Key recommendations include prioritizing CWRs for maximum ecological benefit, integrating thermal refuge enhancement into broader riverscape management plans, and adopting a catchment-based perspective to address upstream influences. 

As climate change continues to warm rivers, it’s becoming harder for temperature-sensitive aquatic species like salmon and trout to survive. These animals rely on cold-water refuges (CWRs)—cool pockets in rivers that offer relief from rising temperatures. However, current efforts to protect or create these refuges are often scattered and uncoordinated.
To tackle this issue, researchers brought together experts, conservationists, and local stakeholders in a workshop to develop a shared set of best practices for enhancing cold-water refuges. They created a step-by-step framework to help guide future projects, including how to choose the most effective types of refuges and where to place them. Real-world case studies from different regions were also shared, offering practical examples of what works and what challenges remain.
The study highlights the need for better tools and technologies—like drones and thermal imaging—to track how and when fish are using these cooler areas. It also stresses the importance of looking at entire watersheds, not just isolated spots, when planning refuge projects. Ultimately, the goal is to help communities and conservation professionals work together more effectively to protect freshwater ecosystems as the climate continues to change. https://onlinelibrary.wiley.com/doi/10.1002/rra.4462

Urbanization and extreme flows are altering stream temperature dynamics, yet our understanding of the impact of urbanization and extreme flows on stream temperature is limited. We deployed 27 water temperature loggers in three headwater catchments over three summers. We categorized flow as low, high, or average and calculated daily water temperature anomalies. Comparing Z scores between flow conditions revealed the impact of extreme events on water temperature. We used multiple linear regressions to identify landscape predictors of water temperature. We found during low flows stream temperatures were significantly warmer. Additionally, urban landscape predictors were linked to reduced warming during low flows. Our study highlights that low flows increase extreme water temperature events; however, this effect was less pronounced in more urbanized sites. High flows did not significantly affect water temperature anomalies. These results underscore the vulnerability of rivers to extreme temperatures during low flows; however, landscape may help mitigate these effects.

Atlantic salmon (Salmo salar) experienced drastic population declines from the mid-1970 s to the early 1990′s throughout their range. The survival of the salmon while at sea is considered as the main driver of these declines, even though the underlying mechanisms are poorly understood. This study aims at improving the general understanding of the ocean distribution and migration timing of sub-adult salmon returning to North America from the waters off southern Greenland that could help determine the drivers of marine mortality. We used animal biotelemetry and numerical modeling to improve our knowledge of Atlantic salmon migratory behavior. We used data from 43 North American Atlantic salmon tagged at West Greenland, of which 5 individuals migrated towards their native rivers, and developed an individual-based model to simulate homing migration from their feeding grounds in South Greenland towards the coastal areas of their native rivers. The tagged and simulated salmon exhibited similar behavior when they encountered the cold water front formed by the southward flowing Labrador Current. The salmon either crossed the Labrador Current near the Newfoundland shelf break or continued their route southward along the warmer side of the cold front. These two pathways emerged as the migration routes split where the shelf slope is less steep. This discontinuity along the shelf break leads to a highly dynamic region, a high sea surface temperature variability, and occasional breaches in the thermal front that favor on-shelf fish migration. The salmon trajectories appear to be deflected when the front temperature is 1 °C or less. The 1 °C isotherm would thus bound the thermal distribution of North American Atlantic salmon and shape the species migration routes.

Riverine fishes face major challenges like habitat loss and climate change, which impact the productivity of their ecosystems. While factors like water temperature are often studied, the distribution and availability of food—key to fish growth and survival—remain less understood.

This paper expands on the concept of “foodscapes,” focusing on three aspects of food: abundance, accessibility, and quality. It addresses why food availability is hard to estimate, the consequences of uncertainty, and emerging methods to better measure it.

The authors emphasize the critical role of food in fish conservation, particularly as waters warm.

This study examined how surgery and recovery time after acoustic tagging affect the survival and migration of wild Atlantic Salmon smolts through freshwater, estuarine, and marine environments.

Four treatment groups were compared to assess the impacts of hatchery conditions and post-tagging recovery time. Results showed that short recovery times and hatchery captivity reduced survival, especially within the first 5 days or 48 km after release, with lingering effects during the transition to saltwater.

Hatchery fish migrated faster, likely due to larger size, but still experienced reduced survival. These findings highlight the importance of quantifying tagging-related effects in the wild, as such biases can influence conclusions about natural fish behaviour and survival.