Under climate change, it is anticipated that river water temperature will increase - reducing thermal suitability for cold-water adapted native fish and heightening risks from invasive species. Atlantic salmon and anadromous brown trout are iconic species of high economic and conservation value, which are often the focus of management action.
In recent years, fisheries management organisations have tried to protect rivers from the detrimental effects of high water temperature under current and future climate. Riparian tree planting (to shade rivers and cool waters) is a well-promoted management option. However, concerns have been raised about the lack of reliable underpinning evidence to identify: (a) where rivers will be hottest, (b) where river temperatures will change most, and (c) where riparian tree planting will have the greatest effects (targeted based on a and b).
Our research addressed directly these needs and was co-created, developed and translated into decision support tools in collaboration with the Scottish Government - Marine Scotland Science (MSS).
More than 15 years of collaborations led by The University of Birmingham (Prof. David M. Hannah) and MSS (Dr Iain Malcolm) has provided insights about: controls on river water temperature (Hannah et al., 2004, 2008; Garner et al., 2015; Dugdale et al., 2018); space-time variability of river temperature patterns (Malcolm et al., 2004, 2008); opportunities for management interventions to avoid high temperature extremes; and potential climate change impacts on river temperature.
Dr Grace Garner provided new fundamental process understanding of the heat and water exchange processes controlling river temperature under different riparian tree cover scenarios (Garner et al., 2014; 2017). This process-based modelling and scenario testing revealed the conditions under which riparian shading has maximum impact on water temperature at the river reach to sub-catchment scale.
In parallel, the CAMERAS Freshwater Monitoring Action Plan identified the need for a bespoke monitoring network across Scotland to improve understanding of river temperature at the larger (catchment to national) scales to inform resource management.
The University of Birmingham and and MSS designed and developed the Scotland River Temperature Monitoring Network (SRTMN) based on understanding from our earlier studies. Local fisheries organisations (supported by MSS) delivered the network, deploying and downloading 223 dataloggers across 13 catchments