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 four 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.

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.

Click below to read local Riverfly Census reports:

Support smarter monitoring to achieve real results in your river

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, and if you would like to support us to roll it out further across the UK then please see our SMARTrivers campaign.

Latest Riverfly Census News

Bakkavor ends use of cleaning products containing chlorine

15/03/2019
Bakkavor has stopped using chlorine-based cleaning products at its Alresford Salads salad washing and packaging factory near Alresford. This means that the chemicals used every night to clean the factory’s equipment will not be able to react to form chloramines which are highly toxic to water life even in extremely low concentrations. The EA and […] Read More

Septic tanks – the UK’s secret sewage problem

18/02/2019
Septic tanks are not the most glamorous topic… …But they are definitely the ‘elephant in the room’ when it comes to protecting our waters from nutrient pollution. What are septic tanks? There are a vast array of homes that are not linked up to main sewage treatment works. Where properties are located at least 50 […] Read More

A dismal end to 2018 for water companies, their regulators, and the government

22/01/2019
The end of 2018 was not pretty for water companies. Sadly, as always, our environment and waterways bear the brunt.    Thames Water: deliberately ignoring alarms First up was Thames Water, fined £2 million at Oxford Crown Court on 21st  December for a pollution incident in 2015 in which two Oxfordshire streams were polluted with […] Read More

Using data to protect wild fish: River Coquet hydropower

09/01/2019
  River Coquet Hydropower With the feed-in-tariffs for hydropower ending in March after little activity over the past couple of years, the beginning of 2019 has seen a flurry of applications for new hydro schemes. For us, this has once again highlighted the importance of our Riverfly Census data to provide evidence, not just anecdote, […] Read More

2018: A year in review

21/12/2018
What have we achieved this year? 2018 has been our biggest year yet! So where has your support got us, and what have we done for wild fish protection and conservation? Our CEO’s Year In Review summaries our influence, accomplishments and campaigns over the past 12 months.  View our full YEAR IN REVIEW HERE With […] Read More

Latest data on River Test and River Itchen reveals concerning issues

17/12/2018
  Test and Itchen are no exception to grim decline in water quality and flylife The S&TC Riverfly Census continues to reveal worrying declines in flylife and water quality in rivers across England and Wales, as confirmed by our latest report on the River Test and the River Itchen (the king and queen of our […] Read More

River Itchen damage below Alresford Salads: Autumn 2018 photos

15/10/2018
New photos show damage in River Itchen below Bakkavor’s Alresford Salads factory. At S&TC we have long been campaigning to stop Bakkavor discharging their salad wash effluent into the headwaters of the River Itchen. The Itchen is a designated Special Area of Conservation (SAC), and we fear that the chemicals in their discharge are harming […] Read More

Agricultural Bill: Is a ‘Green Brexit’ possible?

20/09/2018
The first major Agriculture Bill for over 70 years has now been published, promising a cleaner, greener and healthier environment post Brexit Currently farmers receive €4 billion in subsides each year, which is divided up related to the total amount of land farmed. For current subsidies farmers do not need to ‘do’ anything. The new […] Read More

River Itchen pollution: Alresford Salads trial chlorine-free cleaning products

13/09/2018
Is the end of chlorine-based cleaning products at Alresford salad washing plant finally in sight? Finally, it appears Alresford salad washing plant is planning to stop using chlorine-based cleaning products. This would mean that there would no longer be any products used to wash the site’s equipment that could react to form chloramines, which are […] Read More

High resolution monitoring is essential for river conservation

07/09/2018
This is a re-posting of an original article from Environmental Technology   High Resolution Monitoring on the Itchen Working on behalf of Salmon & Trout Conservation (S&TC), researchers from the University of Portsmouth have been investigating nutrient concentrations in the Upper River Itchen, in Hampshire, UK, to better understand where phosphorus is coming from and […] Read More

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