Impact of climate change on rivers

River managers will be able to limit the impact of climate change on Scotland’s rivers and fisheries by using a new online mapping tool to plan mitigation work

Scientists at Marine Scotland and the University of Birmingham have developed a river temperature model to predict the maximum daily river temperatures and sensitivity to climate change throughout Scotland, with interactive maps made available through the National Marine Plan interactive website.

Scotland’s rivers account for around 75% of the UK and 30% of European wild salmon production, with freshwater fisheries and associated expenditure contributing more than £79 million a year to the Scottish economy.

However, with Atlantic salmon sensitive to changes in river temperature and temperatures expected to increase under climate change, there are concerns Scottish rivers could become less suitable for salmon.

Environment Secretary Roseanna Cunningham said:

“We know a number of complex factors, including climate change, are affecting wild salmon numbers in the north east Atlantic region.

“This research identifies areas where our famous salmon rivers are at risk due to climate change and  will help fisheries managers  target work to protect stocks and increase the resilience of our fresh waters.

“It is vital we take decisive action to safeguard wild salmon stocks and we will continue to work with Fisheries Management Scotland and their members to do so.”

Alan Wells, Chief Executive of Fisheries Management Scotland said :

“Scotland’s Atlantic salmon populations are subject to a range of pressures and increases in freshwater temperature, associated with climate change, will increasingly need to be managed.

"Our member District Salmon Fishery Boards and Fisheries Trusts are engaged in projects to plant trees near rivers, in order to provide dappled shade and reduce extremes of temperature in our rivers. This model will be a valuable tool in targeting these efforts so that we can maximise the beneficial impact on our rivers.”

Mark Bilsby from the River Dee Trust said:

“This is a really useful piece of work as it will allow us to target our resources on those parts of river in most need of trees to create shade and bring the temperatures down. The practical measures of planting trees to offset the local impacts of warming temperatures is well proven and this will put them where they are most needed.”

Simon McKelvey from the Cromarty Firth Fishery Board, said:

“The Cromarty Firth Fishery Board, like many other fishery management organisations in Scotland has been undertaking a programme of native riparian woodland restoration for a number of years.  The  ecological benefits of riverside woodland are well recognised in terms of; nutrient input, sediment control, cover for wild fish and natural flood management. This work will allow us to plan planting to ensure that the maximum benefits from shading are also achieved.”

Background

Fisheries management organisations have also been involved with the new project, which identifies the rivers that are greatest risk of  climate change impacts, making it easier for river managers to take forward mitigation measures. This work could include planting trees on river banks to increase shading or managing water demand and use.

The Scotland River Temperature Monitoring Network (SRTMN) was set up in 2013 to provide this information. It is a scientific collaboration between Marine Scotland Science Freshwater Fisheries Laboratory and the University of Birmingham delivered with support from local fisheries trusts and boards.

Maps of maximum river temperature and climate sensitivity for Scotland to allow managers to plan where to plant trees.

The Scotland River Temperature Monitoring website.

Leaflet to help fisheries managers understand how to use the available resources to plan riparian tree planting

The scientific paper underpinning the NMPi maps.