20 Apr 2021

Aquatic Habitat Survey Results

Andrew Farr very kindly volunteered his time recently to visit Darch's Wood in order to conduct an aquatic biodiversity survey.

He sampled the stream from the top of the woods at TQ567214 south down the ghyll to the pond, which he also surveyed. His survey uncovered three mayfly species and one stonefly species, which are listed below. He also collected a dragonfly larva which was identified as being of the large and beautiful Golden-ringed Dragonfly.

  • Mayfly
    • Large Dark Olive Baetis rhodani  
    • Ditch Dun Habrophlebia fusca
    • Pond Olive Cloeon dipterum  (only present in the pond)
  • Stonefly
    • Leuctra nigra (only present at the top of the site)
  • Dragonfly
    • Golden-ringed Dragonfly  Cordulegaster boltonii 
A female Golden-ringed dragonfly
  • Other Orders (not Mayfly Stonefly or Dragonfly):
    • Freshwater Shrimp: Gammarus, by far the most common freshwater invertebrate at Darch's Wood; present at all sites sampled.
    • Sedge:  Very few in the main stream but a tributary sampled held numerous cased caddis larva. Unsurprisingly given all the leaf mould in the stream they were encased in tiny bits leaf not small stone gravel! He also collected one uncased caddis larva.
    • Midge larvae: a few here and there, of the non-biting variety!
A freshwater shrimp! Hurrah!

Although no show-stealing rare species were found during the survey, the results do show that the aquatic environment in Darch's wood is in reasonable order, clean and relatively unpolluted. Although greatly encouraging, the amount of life Mr. Farr discovered is perhaps also a little surprising given that the pond is crammed full of enormous, non-native carp who eat almost everything that moves and most things that don't!

Many thanks to Mr. Farr in his effort to sample the site and present the committee with his results.

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