Peter Coleman-Smith reports…
We had a good riverfly session yesterday in Blaise Castle Estate with Tim and Mike doing the last sample of the year. We found a caseless caddis (a rarity here), a number of olive nymphs and lots of freshwater shrimps which meant a score of 6 vs the site threshold of 3. The result was entered into the national database.
Sadly there was lots of silt blanketing the stream-bed in many places. Later Mike and I walked up to the outfalls from the A4018 building sites and he phoned them in on the Environment Agency pollution reporting line (0800 807 060). We will keep up the pressure to get effective controls deployed and the stream restored.
Riverfly site yearly average scores
2025 was very dry, stressing the riverlife for an extended period but a wet autumn has helped.
All 3 of original sites on the Trym and Hazel Brook (there are other sites as well now, not included here) had a slight dip in 2025 vs 2024. Even so, all are slightly improving which is great! However, diversity and abundance of invertebrates in our river remains poor vs many other rivers. Dodgy water quality, variable flows (very low and warm in the summer) and over-shading of the channel (so little aquatic vegetation) don’t help.
