The Riverfly Partnership

The Riverfly Partnership is a unique data collection programme, hosted by us at the FBA, which engages in the management and conservation of freshwater environments (specifically rivers) through surveying of aquatic insects.

The Partnership works with anglers, scientists, water course managers and authorities to:

  • Protect water quality of rivers
  • Further understanding of riverfly populations i.e. mayflies (Ephemeroptera), caddisflies (Trichoptera) and stoneflies (Plectoptera)
  • Actively conserve riverfly habitats

The Partnership aim to accomplish this through the raising of awareness concerning the importance of conserving riverflies and their habitats, and promoting positive management techniques. Another important way in which they protect riverfly populations is by encouraging and leading citizen science, involving the public in monitoring and recording of riverflies in their local rivers. The Riverfly Partnership has led to the creation of the ARMI Dataset - this is information on riverfly populations which has been collected by trained volunteers, to support the work of UK environment agencies.

This data is freely available for all use, on the website

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What are riverflies?

Riverflies include three groups of insects at the very heart of freshwater ecosystems; mayflies (Ephemeroptera), caddisflies (Trichoptera) and stoneflies (Plecoptera). They are a vital link in the aquatic food chain as a food source for fish, birds and mammals. Populations are affected by any factors, predominantly water quality, habitat diversity, water level and flow rate.

Mayfly - Ephemeroptera 

Ephemera’ – short-lived, ‘ptera’ - wings

Mayflies, also known as ‘up-wings’, are an important food source for fish, birds and other invertebrates, both as adults and nymphs. They need clean water in order to reproduce and feed, so populations are struggling as our river habitats get dirtier.

Adult mayfly

Did you know?
They are one of the longest lived group of animals on the earth; our first written record of them comes from a text over 4,000 years old, but we know they were around even before then, some 300 million years before. Despite this long history, they are known for being short-lived because in some of species of mayflies, the adults are alive for just one day!


Caddisfly - Trichoptera

 ‘Trichos’ – hair, ‘ptera’ – wings

Caddisflies are another important food source for river animals, particularly in their adult stage. Their larvae are also fantastic grazers, which clean up old leaves and twigs from the river bed, neatly sorting sediment as they go. These insects suffer in poor quality water and are sensitive to pollution.


Adult caddisfly

Did you know?
It was at one point quite trendy to use caddisfly cases as jewellery! In the wild, juvenile caddisflies use stones, wood and sand to produce elaborate cases that protect them from predators. They like certain materials more than others, but will use whatever is available to them – including gold leaf and small jewels, making glitzy little tubes to live in.


Stonefly - Plecoptera 

Pleco’ – folded, ‘ptera’ – wings

Stoneflies are predator and prey in equal measure; their nymphs are large compared to caddis and mayflies, so they often feed on other small aquatic animals. But, they are favourite food for fish too, especially in their clumsy adult stage. Stoneflies are completely intolerant to pollution, so they make an excellent indicator species for water quality. 


Stonefly nymph

Did you know?
Stonefly nymphs are incredibly hardy when it comes to extreme conditions. Not only can they continue to grow in sub-zero temperatures, but they can also suspend their growth if the river dries up!


Riverflies may be small, but they are mighty! Their importance in the freshwater environment should not be underestimated; they are a vital part of both the aquatic and terrestrial food chains, as well as being key players in sorting sediment on the river bed and breaking down waste products like old leaves and twigs.


You Can Help - Become a Riverfly Volunteer

If you are passionate about protecting the riverfly populations of the UK, and their habitats, you can become a Riverfly Volunteer with The Riverfly Partnership. All you need to do is go on to the website and check out the events page for Riverfly training events near you. You can also follow The Riverfly Partnership on Twitter to receive regular updates.


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