Field Event Reports

Sunday 16 September: Pond Dipping at Orchard Lake

Leader: Jeremy Biggs: Director, Freshwater Habitats Trust

Graham recorded the finds at the end of the session

A group of 16 people (9 adults, 7 children) met at 10.30pm at the top of Barton Lane, Abingdon, where we were met by our guide and expert, Jeremy Biggs. Initially there was some rain in the air, but this soon cleared for the rest of the visit. Loaded up with nets, trays, books and other materials, the group then walked the 15 minutes or so up the Sustrans path, turning south to Orchard Lake. This former gravel pit is ideal dipping as at its western end it is shallow, but bordered by a healthy edge of aquatic vegetation, most of which only just emerges from the water surface. Dipping started, with children waving nets enthusiastically. It was soon apparent that a profusion of life was being found, with trays rapidly filling with swirls of bugs and beetles. Jeremy was then called upon to identify the unusual among the bugs and various detritus. Notable finds were Water Scorpions, Emperor Dragonfly and Hairy Dragonfly nymphs, Smooth newt efts, a Stickleback and a Minnow. The trays buzzed with Screech Beetles and Waterboatmen. Five species of water snail were found.

Perhaps the only disappointment was that we did not see the Osprey that had been frequenting the Lake for several days and indeed was seen fishing in Orchard Lake just an hour and a half before we arrived. A Mute Swan seemed unperturbed by our presence as it cruised around the lake, while at least one Water Rail was heard periodically 'squealing' from the cover of the far bank.

As with all AbNats pond dips, there was great satisfaction seeing the delight on the children's faces as they discovered the profusion of life that is normally invisible. Several even enjoyed putting on what were oversized waders so they could venture out farther into the Lake, even though the vast majority of 'life' was captured in the shallows amongst the vegetation.

It was some time after midday that the youngsters had to be dragged out of the water to tidy up and collect the equipment whence we trudged back to the cars. Thanks were conveyed to Jeremy for his time, expertise and loan of his equipment.

Species identified:
Great Diving Beetle (Dytiscus marginalis), Screech Beetle (Hygrobia tarda), Common Orb Mussel (Musculum lacustre), Water Hog-louse (Asellus aquaticus), Freshwater Shrimp (Gammarus pulex), Pond Olive (Cloeon dipterum), Common Backswimmer/Waterboatman (Notonecta glauca), Lesser Backswimmer /Waterboatman (Corixia punctata), Saucer Bug (Ilyocoris cimicoides), Water Scorpion (Nepa cinerea), Wandering Pond Snail (Lymnaea peregra), Great Pond Snail (Lymnaea stagnalis), Ramshorn Snail (Planorbis planorbis), Keeled Ramshorn Snail (Planorbis carinatus), Little Whirlpool Ramshorn (Anisus vorticulus), Emperor Dragonfly nymph (Anax imperator), Broad-bodied Chaser nymph (Libellula depressa), Hairy Dragonfly nymph (Brachytron pratense) + plus several unidentifiable exuvia, Blue Damselfly nymph (Enallagma cyathigerium), Red-eyed Damselfly nymph (Erythromma najas) + other unidentified nymphs, Nine-spined Stickleback (Pungitius pungitius), Minnow (Phoxinus phoxinus), Smooth Newt eft (Triturus vulgaris).
Attendees
Alan & Elizabeth Drury + Zac &Ted, Jaco & Elena de Groot + Teo & Anna, Katharine & Ian de Villiers + Joanne & Gail, Graham Bateman + Alex Reeves, Adrian Allsop, David Guyoncourt.
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Report: Graham Bateman

Jeremy Biggs started the children off on an enthusiastic pond-dipping session.Children soon forgot to keep water out of their wellies.Creatures from nets were transfered to trays with clean water

Listing the species found was the final important activity. This spider was rescued from the water surface. We found several Water Scorpions.

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