Riverfly Census

The Riverfly Census was a milestone S&TC project which used aquatic insects to tell us about the of the health of our rivers.

The study used standardised monitoring of aquatic invertebrates to reveal how pollution from agriculture, sewage-treatment works, septic tanks and chemicals from many sources is killing our rivers.

This project has now concluded.

However, our SmartRivers programme carries on this work enabling community groups, trusts and other organisations to benchmark and monitor the health of their own rivers.

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

Why Survey Riverflies?

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.  

The Census Process

Across English and Welsh rivers, we have professionally sampled and analysed invertebrate life to understand the the water quality issues that 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.

Use our interactive map above to view the local reports.

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.

Latest Riverfly Census News

Severn Trent to adopt SmartRivers

11/11/2020
SmartRivers welcomes its first water company hosted volunteer hub We are pleased to announce that Severn Trent is the first water company to enrol into the SmartRivers programme. SmartRivers is the volunteer arm of the Riverfly Census, where invertebrates are sampled and analysed to species-level. The species lists are then used to calculate biometrics that […] Read More

Sewage (Inland Waters) Bill

15/10/2020
Philip Dunne MP launches new Bill to tackle river pollution Salmon & Trout Conservation warmly welcomes the introduction of the Sewage (Inland Waters) Bill, aimed at tackling the unacceptable levels of raw sewage being discharged into our rivers and streams. Rt. Hon Philip Dunne MP for Ludlow has published his Private Member’s Bill designed to […] Read More

It’s the perfume that you notice first.

15/10/2020
“If we can’t conserve the most protected, how can we ever conserve the rest?” Feargal Sharkey, recently appointed a Salmon & Trout Conservation Vice President writes, It’s the perfume that you notice first. Not in that pleasingly attractive CHANEL N° 5 kind of a way but more in that acrid, back of the throat, ammonia […] Read More

Time for bespoke regulatory targets for all chalkstreams

13/10/2020
Chalkstreams are as internationally rare and ecologically important as coral reefs or rainforests, and 85% of the world’s chalkstreams are found in England. With this comes a responsibility to protect them, something at the moment we are failing to deliver, with evidence of many stretches running dry, whilst others are clogged with nuisance algae and huge […] Read More

SmartRivers developments and achievements during lockdown

02/10/2020
As with everything right now, SmartRivers (the volunteer arm of the Riverfly Census) is navigating its way through the ‘new normal’. However, despite restrictions forcing us to postpone travelling and training courses this year, lockdown gave us the time to make SmartRivers even smarter.   SmartRivers – now an IFM certified course We are delighted […] Read More

MoRPh: a tool for assessing river habitats at biological monitoring sites

25/09/2020
As you probably already know, SmartRivers is proud to be part of the Riverfly Partnership’s ‘Riverfly Plus’ toolkit, alongside other exciting citizen science projects like MoRPh – the modular river survey River organisms respond to their environment and so it is important to monitor any environmental changes. Often the environment is characterised through water chemistry […] Read More

Persistence pays off in the pursuit of a pesticide problem

18/08/2020
This is a terrific outcome for the river, wild fish, the wider environment and the local community. Nick Measham, CEO S&TC writes, Bakkavör is closing its salad washing plant at Alresford on the Upper Itchen. In simple terms this should result in an end to significant chemical pollution and provide much needed respite for all […] Read More

Phosphorus, Chickens and the River Wye

18/08/2020
S&TC’s agricultural policy is simple; incentivise farmers to invest in their infrastructure and spread the word about modern soil management, but always be prepared to use the current legislation to regulate persistent offenders… Paul Knight, S&TC Fisheries Consultant George Monbiot writing in the Guardian recently highlighted the dreadful state of Welsh rivers.  He focussed on […] Read More

Thirty-six toxic pesticides washed into headwaters of SAC chalkstream

23/07/2020
Bakkavör washing unknown quantities of thirty-six toxic pesticides, which present real danger to aquatic life, into headwaters of SAC chalkstream Following on from our recent release about dangerous quantities of toxic neonicotinoid Acetamiprid being washed off salad leaves into the headwaters of a protected chalkstream, a further freedom of Information (FOI) request proves this is just […] Read More

SmartRivers launched in Wales

12/06/2020
S&TC Cymru launches its first SmartRivers hub in partnership with the South East Wales Rivers Trust S&TC Cymru is delighted to announce that South East Wales Rivers Trust (SEWRT) is to host the first SmartRivers hub in Wales. The hub is certain to play a valuable role in assisting SEWRT restore the natural beauty and […] Read More

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