Cold-Water Refuges

About US

Across the world, water temperatures in rivers and streams are increasing, threatening the habitat of economically important and culturally relevant cold-water fish such as salmonids. Climate changes exacerbate human activities impacts on water temperature and water demands, and land-use changes (e.g., agriculture, urbanization). When fish experience thermal stress, they thermoregulate by accessing cold water habitat patches called cold-water refuges (e.g., upstream shaded areas, tributaries, groundwater upwelling zones). In these cold-water refuges, fish are protected from unfavorable high temperatures and can escape the potentially life-threatening metabolic consequences of thermal stress.

The scientific understanding of the processes causing thermal degradation and the importance of cold-water refuges for fish are relatively well known. However, other aspects of cold-water refuges, such as their ecological benefits, quality, and level of protection, restoration, and management, are inconsistent across the globe. Moreover, there is a growing recognition that knowledge gaps or misalignments between the current state of science and policy may be inhibiting cold-water refuge conservation.

Mejia explains that the diversity of researchers “expanded my vision of what we can do in this field and how we can tailor some of the science we are doing to be more directly applied to management.”

SESYNC, 2021

We held a SESYNC workshop ( that brought together an interdisciplinary team of researchers from the United States, Europe, and Canada to address and discuss the following question “Does current science support the management and policy needs of cold-water refuges for salmonids in a changing world?” The workshop was led by Dr. Valerie Ouellet, a diadromous species scientist working with the National Oceanographic and Atmospheric Administration (NOAA), and Dr. Francine Mejia, Biologist at the United States Geological Survey (USGS). Our group of twenty-five participants gathered virtually to synthesize the current states of science, policy, and management related to cold-water refuges to identify research and policy gaps that may be hindering the implementation of cold-water refuge management.

Ouellet reflected on the workshop experience in saying “When you bring experts together and they learn from each other, as you are learning yourself, you know you’ve put a great team together!”

SESYNC, 2021

We plan to continue working together and developing innovative products that explore the issues discussed at the workshop. Mejia and Ouellet are leading this work and finishing a synthesis paper to be published this spring (2022) on the workshop’s content in collaboration with the group’s participants. Lastly, some attendees participated in a special session (Keeping cool: thermoregulating in a changing world) at the 2021 American Fisheries Society meeting ( to share their research progress.

This website is designed for managers and researchers to communicate with each other and provide: (1) more information on the case studies used for the workshop, (2) a list of references relevant to CWRs science and management, and updates on collaborative outputs from this group (3) show examples of large and complex datasets compiled in user-friendly ways. For instance, the Interactive Catchment Explorer (ICE) project illustrates how it can help identify potential cold-water refuges and generates collaborations with resource managers and community members to create interactive maps of key areas to enhance the protection of cold-water refuges.

We are looking forward to continuing growing this community!