Riverfly Census

You may be wondering: how can something as small as an insect have any value in something as vast as a river? The fact is, without water insects, our fish, birds and river mammals will struggle to find enough food.

Unfortunately, numbers of these bugs are lower than ever on a national scale. However, our Riverfly Census campaign is the first step towards understanding the decline and finding solutions!

Water insects are great indicators of water quality. They live for months, sometimes years, below the surface in their nymph stages. Because different insects have different tolerances to pollution, the presence or absence of certain species is a simple but effective way of finding out what pressures a river might be experiencing.

Here’s how we use insect samples to find out what’s going on:

Census Process Image 1

A 3-minute kick sweep sample is taken at a river site making sure to survey all the different habitat types.

Census Process Image 2

The sample is pickled using a special alcohol. This preserves the insects so that counting and identification can be done at a laboratory.

Census Process Image 3

The sample is sorted into groups by an expert and the insects are identified to species level using a microscope.

Census Process Image 4

The list of species present is put into a unique scientific calculator. This gives a value for how much the site is being impacted by four key stressors.

Check your river

See how your river did in our 2016 survey:

Join the monitoring revolution

We need people like you to change the way our rivers are managed by demanding better protection and monitoring.

We can organise training for people who wish to be more ‘hands-on’ by becoming citizen scientists to monitor the condition and quality of their own river.

Alternatively, get in touch with us so that we can take forward issues with local MPs or the Environment Agency.

Agreeing Local Bespoke Targets

Our Census sparked the development of unique insect targets for the rivers Test and Itchen.

Hampshire Environment Agency will now feature these targets in their own monitoring.

We are working to agree simple benchmarking figures like this for all rivers so that we can help local river managers develop solutions.  Citizen scientists have an important monitoring role to play in this initiative in future.

Science archive

Support smarter monitoring to achieve real results in your river

Fed up of not really knowing the story under the surface? We see a future where all rivers in the UK have intelligent monitoring and an accurate baseline for measuring positive change. The Riverfly Census is a proven methodology to obtain these benchmarks, but we need your support to roll it out further across the UK.