On 16 August 2022 Montgomeryshire Wildlife Trust held a ‘River Critters’ day at Deri Woods here is a list of what was found in the River Banwy by the general public and identified by experts.
| Species name | Common name |
|---|---|
| Baetidae | a swimming mayfly |
| Ecdyonurus | a stone-clinging mayfly |
| Leuctra | a stonefly |
| Gerris (Aquarius) najas | River Skater |
| Limnephilidae | a caddis fly |
| Rhyacophila | a caddis fly |
| Simulium | a blackfly |
| Dytiscidae | a diving beetle |
| Gammerus | a freshwater shrimp |
| Austropotamobius pallipes | White-clawed Crayfish |
| Oligochaeta | an earthworm |
| Hydrobiidae | a freshwater snail |
12 species