Riverfly Census

understanding and improving water quality in UK rivers

Insects (which make up 97% of all animal species) have declined 59% since 1970

This is hugely problematic for wild salmon & trout, who need need healthy water environments to thrive.

But why are aquatic insects so important?

Foundation of life

Small but all-sustaining, insects are food for our wild fish, birds and mammals. Without invertebrates, the food web would collapse.

Long-term health indicators

As nymphs, insects are constantly exposed to the water, sometimes for years. A water sample would only give you river health information for a single point in time.

Excellent storytellers

Every invertebrate is unique, thriving in a specific set of conditions. The types of bugs present and absent from a sample indicate what pressures a river may be experiencing.

We frequently talk about missing flylife and lack of fish compared to the 'good old days', but anecdotal evidence like this has little weight in environmental decision making.

The Riverfly Census was our way of collecting much needed high-resolution, scientifically robust data about water quality in our rivers.  

Riverfly Census

Across several iconic rivers, we have professionally sampled and analysed invertebrate life to understand the health of the river and the issues which need tackling.  

We use this professional, scientific evidence to campaign for improved protection of our wild waters.

SCOPE

The Riverfly Census has spanned three years. It began in 2015, with 12 rivers across England. Multiple sample sites were carefully selected on each river.

SAMPLE

Kick sweep sampling was completed in spring and autumn to EA guidelines, at all sample sites. Sampling and species-level identification were carried out independently by professional external consultants, Aquascience Consultancy Ltd.

STUDY

Species presence/absence data was inputted into Aquascience’s biometric calculator to obtain scores against key stress types. The data was then evaluated in a whole catchment context to pinpoint likely suspects contributing to river deterioration.

MAKE A STAND

The data was compiled, and is being reported to stakeholders and policy makers, to improve management and conservation of our rivers.

How do we sample?

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 five key stressors.

What have we found?

The Riverfly Census is producing two main outputs:

A national baseline

Watch this space, we are working hard to generate a national summary of our findings, using the data to drive national policy improvements and influence more robust baselines.

Click below to read our national conclusions & policy recommendations:

Screenshot 2019-05-29 at 10.41.00

Evidence to drive local improvement

In progress, we are currently compiling local information and delivering our results to relevant policy makers and stakeholders. See our map below and keep an eye on our news for release of local reports.

Use the map below to find our local Riverfly Census reports:

The Riverfly Census is evolving...

We see a future where all rivers in the UK have intelligent monitoring and an accurate baseline for measuring change, but we cannot do this without your help.

If you want to be involved in smarter monitoring that achieves real results in your river please visit SmartRivers.

Latest Riverfly Census News

River Invertebrate App – Status Update

07/11/2019
We are aware users of our invertebrate identification app have been experiencing access issues. S&TC apologises for any inconvenience caused. We are aware users of our invertebrate identification app have been experiencing access issues. S&TC apologises for any inconvenience caused. Due to a problem out of our control we have had to migrate the app […] Read More

Agricultural Pollution Update – Nov 2019

06/11/2019
Government figures show currently only 14% of rivers are classified as healthy….. Government figures show currently only 14% of rivers are classified as healthy and rural areas are impacting 35% of waterbodies (EA, 2015). Evidence from the Riverfly Census has shown the greatest stressors on our rivers are sediment, excess nutrients, pesticides and other toxic […] Read More

SmartRivers Update – Great Stour

06/11/2019
This autumn we took SmartRivers to the beautiful county of Kent. Thanks to the generosity of Stour Fishery Association we were able to start working on the Great Stour, an interesting river that begins away from Kent’s chalk downs, yet enjoys the full character of a chalk stream due to significant influxes of groundwater from […] Read More

Riverfly Partnership News

30/09/2019
There are many Riverfly monitoring schemes around, so it can be tricky to understand why so many different schemes are necessary. As the population continues to expand, and our dependence on the environment increases, it is more important than ever that we keep a close eye on the health of our water ecosystems. Thankfully, there […] Read More

SmartRivers is delivering results

12/09/2019
The hot dry summer has exposed the stress our rivers are under Nick Measham, Deputy CEO, S&TC To view the full interview click HERE The hot dry summer has exposed the stress our rivers are under – particularly in Southern chalkstreams where algal growth and sediment is choking life to a seemingly unprecedented extent. Once […] Read More

Discharges from salad washing – Update

31/07/2019
Salad washing on the Upper Itchen: A local problem with national significance… Nick Measham , Deputy CEO, S&TC writes……. S&TC’s battle to stop Bakkavör discharging pesticides and chlorinated plant-cleaning chemicals from its salad washing activities is achieving increased environmental protection, and not just for the Upper Itchen. [Previously covered by BBC Countryfile] As a result […] Read More

Chalk streams debated in parliament

31/07/2019
We always intended the Riverfly Census to be a lobbying document as well as reporting on the science, and this has been an excellent first political outing for it. Paul Knight, CEO, S&TC In a speech during a House of Commons debate on “Degraded chalk stream environments”, Richard Benyon MP cited evidence from S&TC’s ground […] Read More

Dear Phil, Thank you so much!

26/06/2019
What can we say other than a huge THANK YOU!! Phil Chessum took on the challenge of running the Race to The King ultramarathon to raise money for S&TC. An exhausting 52.4 mile slog across the South Downs. Completing the course in a very respectable 10 hours 26 minutes and finishing 71st out of 750 competitors, Phil’s feet seemed to […] Read More

Response to Southern Water Fine

25/06/2019
  Ofwat has imposed the biggest fine ever on a water company for “significant breaches of its licence conditions and its statutory duties.” Southern Water has been fined £37.7m, but this has been reduced to £3m because the company has undertaken to pay customers some £123m over the next five years. Ofwat states in its report: […] Read More

Bakkavör Alresford Salads Impacting Upper Itchen

17/06/2019
  Sewage and pesticides from a salad washing factory owned by Bakkavör Group Plc may present a serious threat to aquatic invertebrate life on a highly protected English chalkstream.  The Environment Agency’s response to a formal notification of environmental damage made by S&TC in June 2018, pursuant to the Environmental Liability Directive, confirms the wild […] Read More

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