A better understanding of how river temperatures fluctuate could provide a way to measure how climate change is affecting us, according to a study published in a new scientific journal called Nature Water.
Measuring temperatures in rivers is a good way to assess water quality. This also influences physical, chemical, and biological processes in the water, which in turn, impacts ecosystems, human health, and industrial, domestic, and recreational uses by people. For these reasons, researchers from the University of Birmingham, UK, have called for an increased focus on both river temperatures and the factors causing temperature increases.
The team argues that we need a better understanding of the role played by humans on river water temperature. This will help us recognise how temperature changes affect biodiversity, ecosystem functioning, and risks, including algal blooms, waterborne pathogens, and effects on populations of fish and other aquatic species.
Crucial to this is to re-assess how we monitor and model river temperatures to improve our diagnosis of key changes. This will play an important part in our ability to manage, mitigate and adapt to situations with high temperatures that damage aquatic organisms and ecosystem services for people.
“More attention has been given to other water quality indicators, such as nutrients and contaminants,” explained co-lead author Professor David Hannah, UNESCO Chair in Water Sciences at the University of Birmingham. “However, river temperature influences many of these factors. Emerging evidence shows that river temperatures are rising in response to climate change in many regions worldwide. On top of this, human activity is altering water temperature further; but we still need to better understand this phenomenon and its implications.”
The authors recognise that the knowledge we have at the moment is inconsistent, with large gaps and variations in detail. In addition, any current data comes primarily from more developed countries. This lack of knowledge severely limits our ability to manage rivers, as well as protect ecosystems and balance the competing interests of different stakeholders.
To address these issues, the authors suggest creating an accessible archive for river temperatures, pulling all the available data together to highlight information gaps. This would also promote collaborative research and management efforts with local and indigenous communities and avoid decision-making based on incomplete information.
Ficklin, D.L., Hannah, D.M., Wanders, N. et al. Rethinking river water temperature in a changing, human-dominated world. Nat Water 1, 125–128 (2023). https://doi.org/10.1038/s44221-023-00027-2