One of the aims of TDEG’s Rivers and Brooks Group is to monitor local waterways and gather real evidence about water quality in our area. We’ve been doing just that, with assistance from the Cressbrook and Litton Flyfishers Club and the Freshwater Biological Association. Both organisations have shared their expertise and enthusiasm with us – and we are very grateful for their support.
This work is ongoing. But here is what we are trying to do and some of our early results.
The Riverfly Partnership
A small group from our Rivers & Brooks project have undertaken training with the Riverfly Partnership in order to investigate water quality in Tideswell Brook. The Riverfly Partnership is a national citizen science programme hosted by the Freshwater Biological Association (more info here).
Riverflies are invertebrates that spend most of their life cycle in a river, stream, pond or lake. They include things like Mayflies and Caddisflies. They are vital food for fish, birds and bats and are at the heart of the freshwater ecosystem. They can also be present throughout the year, and different species have specific tolerances to changes in environmental conditions.
Eight different groups of these riverflies form the basis of the Riverfly surveying programme and are regarded as key indicators of the quality of waterways. They are often referred to as the ‘canaries in the coal mines’ of our waterways.
The eight groups we need to study are:
- Cased caddis
- Caseless caddis
- Mayfly
- Blue-winged olive
- Flat-bodied stone-clinger
- Olive
- Stonefly
- Freshwater shrimp
Our small team first had to undertake the Riverfly Partnership training, and be certified to undertake river sampling. This is important to ensure our data is in line with the national programme, and that we understand our possible impacts on the river as well as various health and safety requirements. Of course, we also had to learn how to identify the eight different groups of riverfly!
The first part of the training required the successful completion of an online training course. The second part involved training in the field with our contact from the Freshwater Biological Association. Six of us completed that training this autumn, with more members also wishing to progress through their training later next year.
A count of all the riverflies in each of the eight groups provides us with a total score for the whole site.
Not surprisingly, we found many examples of all eight groups in the River Wye. It is a very ecologically rich river, and a fascinating place to complete our training.
After an excellent day, all six of us had successfully completed the training and we were awarded our certificates.
The following week, our trainer and a colleague from the Wildfish programme, accompanied us to Tideswell Brook – where we attempted the same process in our local stream.
Tideswell Brook proved harder to sample. There is barely any water in the brook after a very dry summer, and what there is vanishes down a crack in the limestone not far from the main car park. Next spring, we hope to sample above and below the sewage treatment works, and also above the village near Water Lane. But this year we only managed a reasonable sample just below the car park in Tideswell Dale.
This sample had an alarmingly low diversity of riverflies – just a tiny number of Olives and mostly freshwater shrimps (only two of our target groups). This is quite concerning. Freshwater shrimps are much more resistant to pollution than any of the other groups. So this may already be telling us something about the water quality in the brook. But we will need to sample more next year to confirm our findings.
We cannot sample over winter, as we do not want to disturb any fish which may be spawning in the brook. But we will be back in the spring to try to find out more.
