Riverfly monitoring in Long Ashton:
A partnership between the LANCE Trust , BART and the Riverfly Partnership
The Bristol Avon Catchment is a unique and beautiful network of rivers and streams, with the Bristol Avon at its heart. Stretching 75 miles from its source in Wiltshire to its confluence with the River Severn, the River Avon and its tributaries are the lifeblood of the area: in Long Ashton we have Colliters Brook and the Land Yeo.
The Bristol Avon Rivers Trust (BART) works to protect and improve our rivers for the benefit of people and wildlife. As part of this work, BART coordinates Riverfly Monitoring across the Bristol Avon Catchment, helping local volunteers play an active role in looking after the waterways on their doorstep.
In Long Ashton, the LANCE Trust and local volunteers have joined the effort, monitoring our watercourses and contributing valuable data about their health.
What riverfly monitoring looks like
About riverfly monitoring
Anglers and local community groups are natural guardians of rivers. Living and spending time close to local waterways puts people in an ideal position to notice changes and help keep watch over their health.
The Riverfly Monitoring Initiative (RMI, also known as the Anglers’ Riverfly Monitoring Initiative or ARMI) was developed by the Riverfly Partnership to give volunteers a simple, standardised way of monitoring river water quality.
Why monitor riverflies?
Riverflies and other freshwater invertebrates are particularly useful indicators of river health. Certain species are very sensitive to pollution, so a sudden change in their numbers can provide an early warning that something is wrong – sometimes before there are any obvious signs visible to a passer-by.
By regularly monitoring and recording these species, and the condition of the stream, volunteers can help identify potential pollution incidents and enable a rapid response from the Environment Agency, or those responsible, before serious or lasting damage is done.
Riverfly monitoring in Long Ashton
BART is leading the ‘Riverfly Partnership hub’ for the Bristol Avon Catchment, coordinating monitoring and providing training for volunteers across the area.
BART approached the LANCE Trust to see whether our volunteers would be interested in monitoring sites in and around Long Ashton. It was an excellent fit with what the Trust is all about: giving local people practical opportunities to understand, enjoy and protect the natural environment around them.
There are benefits for volunteers too. Getting involved provides an opportunity to spend time outdoors, learn new skills, meet like-minded people and make a useful, ongoing contribution to the conservation of our local waterways.
Map: Riverfly monitoring locations on Colliters Brook and the Land Yeo in long Ashton
How does it work?
Riverfly monitoring is designed to be straightforward enough for trained volunteers to carry out regularly and consistently.
Once a month, armed with a net and bucket, volunteers take a three-minute sample from the riverbed at their monitoring site. They then identify and record the presence and abundance of eight groups of pollution-sensitive freshwater invertebrates, with a particular focus on mayflies, stoneflies and caddisflies.
Each monitoring site has a set ‘trigger level’. If the number of invertebrates falls below this level, it can indicate that something may be wrong with the water quality. The relevant authorities can then be alerted so that the cause can be investigated and, where necessary, action taken.
Regular monitoring also builds up a valuable long-term picture of our local waterways, helping us understand how their invertebrate populations – and therefore their ecological health – are changing over time.
Supporting the project
Getting a local Riverfly monitoring group up and running requires more than willing volunteers. Monitors need proper training as well as specialist sampling and identification equipment. We are therefore extremely grateful to Long Ashton Parish Council for providing an essential grant to support the training of our volunteers and purchase the equipment needed to establish Riverfly monitoring in Long Ashton.
Their support has enabled local volunteers to become part of a much wider network of citizen scientists keeping watch over the health of our rivers and streams.
We’re always looking for Riverfly monitoring volunteers to help collect data, please get in touch.
To get a feel for what we’ve been up to, read our blog: What’s in Long Ashton’s streams?
Extracting riverfly larvae from a stream sample for identification. The stream in the image on the left had much more debris - such as leaf litter and silt - than the clearer stream on the right.