Date: 22 September 2026
Activity: Riverfly Survey
Survey Team: Paul, Simon, Marianne and myself
Species Recorded:
- Freshwater shrimp – 100+
- Alderfly nymphs – approximately 30
- Three-spined sticklebacks – 3
- Damselfly nymphs – 23
- Caddisfly larvae – present, number not recorded
Today I joined Paul, Simon and Marianne for another riverfly survey. The water was looking much clearer than it had during the previous survey and appeared to be of good quality, which was really encouraging to see.
The freshwater shrimp were by far the most numerous, with well over 100 counted. We also recorded around 30 alderfly nymphs, 23 damselfly nymphs and three three-spined sticklebacks. Caddisfly larvae were also present, although I did not record the exact number.
One thing I noticed during the survey was that, as the day became warmer, the damselfly nymphs began moving towards the shaded side of the container. Once they had been counted, I released them back into the water rather than keeping them in the container any longer than necessary. I did the same with the sticklebacks once they had been recorded. It was a useful reminder of how quickly conditions in a sampling container can change, especially on a warm day, and how important it is to minimise stress on the animals being surveyed.
It was particularly encouraging to see such strong numbers following the decline we noticed during last month’s survey. At the time, we suspected that blue-green algae may have contributed to the poorer conditions and lower invertebrate counts. Seeing the water clearer again and finding such a good range and abundance of freshwater life felt like a really positive change.
I always enjoy these surveys because they provide such a direct way of seeing how the river is responding to changes in water quality. Today’s results were a reassuring improvement and a great reminder of how useful regular monitoring can be for spotting changes in freshwater ecosystems.
Photographs
Badger Ecology 