Riverfly Monitoring is our flagship citizen science project. Our volunteer monitors sample river bugs throughout Leeds, Bradford and the Dales to assess the effects of pollution on life in the river.
Riverfly populations are one of the key indicators of long-term river health problems, as the insects living in the river fall quickly if pollution is present and take a long time to recover after a pollution event.
Our monitors work in pairs along the rivers and becks to sample an allocated site once a month during Spring and Summer.
To sample a river, volunteers kick the river bed for 3 minutes to release bugs from the gravel so they wash into a net. Hand-sized stones are then turned over for one minute to check for insects that cling to surfaces.
The monitors then sort and count the sample looking for 8 groups of bugs (see right).
The results are logged on the National Riverfly Monitoring Partnership website for approval by our local coordinator. Where problems are found, the results are sent to Environment Agency staff for investigation.
We are currently conducting Riverfly Monitoring in much of the, River Worth and Middle Aire, as well as across the Becks of North Leeds. We are working on expanding into the Aire above Skipton.
We have a large number of Riverfly Monitors working in pairs from Skipton to Leeds alongside a number of volunteers who work in bigger teams known as “Monitoring Hubs”, each of which sample their local river.
The green pins show the location of sampling points as at March 2026
You can also view an interactive map of all our sites and the national database of all records on the Riverfly Partnerships interactive database - click below
Riverfly sampling is a long-term data gathering process that measures the change in river bug populations over many years. Our Riverfly sampling process is still young with only a few years of data gathered during the ongoing growth of our sampling network.
However some key trends are beginning to beginning to show across out sampling sites. Low bug counts are repeatedly being recorded on:
Work is ongoing to identify the causes of these problems and to identify solutions to the issues.
View our LNER Life in the Leeds Beck project report for our most recent findings across North Leeds Life in Leeds Becks - Aire Rivers Trust
We are always looking for new volunteers to count Riverfly across the Aire. Our training programs are delivered in the Summer and focus on areas where we have current river restoration projects.
To find out more about getting involved with Riverfly visit our recruitment page: Riverfly recruitment - Aire Rivers Trust
We have developed a range of materials to help our trained monitors with their sampling.
Click this image to access those resources.
