A random encounter on a trip to Skokholm Island in Pembrokeshire back in June led me to being introduced to Kev Rowley, a freshwater invertebrate enthusiast, predominantly beetles and bugs, who I was told “would be interested in doing some surveys at your reserve”. I didn’t think anything would come of this, but a few weeks ago we finished our base survey of the reserve having carried out dips at 25 sites around our lakes, ditches and ponds.

Over a series of Saturdays from June through to November, I met up with Kev as we worked our way around the reserve. Surveying was undertaken with a pond net sweeping the water and marginal vegetation before examining the catch in a white tray. We attempted to identify all inverts found, either on site where possible or by collecting them for identification under the microscope at a later stage. In total 116 species were IDed;

  • 48 coleoptera (beetles)
  • 29 hemiptera, (true bugs)
  • 13 molluscs (snails and slugs) 
  • 4 crustaceans
  • 4 leaches
  • 18 others.

Some finds couldn’t be IDed to species level, such as mayfly/caddisfly nymphs, water fleas and water mites so the true number of species will be higher than recorded. Each species was scored using the Community Conservation Index (CCI) system which ranks rarity from 1 being ‘very common’ up to 10 being ‘endangered’. Of the 116, 13 species scored a 7, notable, including a nationally scarce pond skater, shore bug and whirligig beetle. Even better, 2 species of Hydrochus water scavenger beetles were found which both scored an 8, rare.

Water stick insect:

Water scorpion:

It was fascinating to go out on the surveys and get an appreciation for many of the small creatures that call the reserve home.

Anonymous