Keston Ponds excursion

Saturday 29th June 2024

Prior to the meeting, Lisa and Nigel Ashby met with Debra van Jaarsveldt, Kelsey Lakes Project Manager at Bromley Council, who wanted to tell us about the improvements they hope to be making to several ponds in the borough. She was particularly interested to make contact with David Linstead, who as a regular visitor to Keston could offer some insight into the microscopical life in the ponds.

There have been excursions to Keston Ponds before, but the last one was many years ago. The ponds are part of Keston Common, which is a Site of Special Scientific Interest, and are still a good location for pond-dipping. Local member David Linstead has collected and photographed all sorts of interesting specimens there. So when a new excursion was proposed, it was enthusiastically welcomed, but on the day just four members and one spouse arrived. Unfortunately our meeting date clashed with some other events, but despite the low attendance our dipping was very successful with nearly every sample providing something of interest. We were also pleased to see a number of bees and butterflies around the Hall in a year when all of us had reported a drop in insect life around us, most likely due to how wet the beginning of the year has been.

Keston Village Hall is not far from the ponds, and has free parking for visitors. We hired the Jubilee Room to set up our microscopes and cameras and a display of photos by David Linstead.

Keston Village Hall

Photomicrographs by David Linstead

After setting up the equipment, and chatting over tea and coffee, Nigel Ashby, Jane Linstead and Alan Wood drove the short distance to the ponds to collect samples and take photographs.

Keston Ponds

Keston Ponds

David recommended several places around the ponds where we could take samples. There were leaves of water-lilies and Potamogeton on the surface, and various other weeds below the surface.

Jane Linstead used a turkey baster, a pipette and a small net to take samples from the edges of the ponds.

Jane Linstead with turkey baster

Jane Linstead with pipette

Nigel Ashby used a plankton net attached to a telescopic landing-net handle to collect samples away from the bank. He sampled from clear water, underneath water-lily leaves and among weeds.

Nigel Ashby with plankton net

Plankton net

The water was clear, so we could see lots of small fish in the ponds, and there were lots of dragonflies and damselflies flying around.

Dragonfly

Back in the Hall, we transferred specimens from jars onto slides and cavity slides for the compound microscopes, and into small Petri dishes for the stereomicroscope.

Samples from the ponds

Samples from the ponds

Lisa and Nigel Ashby brought their Watson zoom stereomicroscope (with a gliding stage), and a simple Brunel compound microscope. The Brunel microscope is available for members to borrow for outreach activities. It has internal rechargeable batteries, and can also be powered from the mains. It has 4×, 10×, 40× and 100× objectives and 10× eyepieces, and comes with a metal carrying case.

Nigel Ashby with Brunel compound microscope

Lisa Ashby with Watson zoom stereomicroscope

David Linstead brought his trinocular Zeiss Standard microscope, with 4×, 10×, 16× and 40× objectives and 10× eyepieces.

David Linstead with trinocular Zeiss Standard microscope

For photomicrographs, David used an afocal arrangement with his Canon EOS M6 mirrorless camera and a Minolta Rokkor 50 mm f/1.4 lens, attached to a Scopetronix Maxview Plus. He focused using the camera’s LCD screen, and used a cordless remote to avoid shake when taking photos.

David’s Canon EOS M6 camera

David taking a photograph

The specimens that we found included rotifers, copepods, Cladocera, ostracods, desmids, bryozoans, Ceratium, Dinobryon, Hydra oligactis attached to hornwort (Ceratophyllum), Volvox, Vorticella, a mayfly nymph and a small newt tadpole.

Photos from the Quekett archives

No sign of suits, ties or hats in 2024, but the plankton nets look very similar to the ones we use now.

Group photo at Keston Ponds in 1922

Undated photo at Keston Ponds

Photomicrographs by David Linstead

In the gallery below, click one of the small photos and you will see a larger photo with more information. On the large photo, click > or < at right and left to see the next and previous photos, or click at top right to start a slide show, or click at top right to return to the gallery.
You can also use the right and left arrow keys on your keyboard to move between the large photos, and the Esc key to return to the gallery.

Acknowledgements

Our thanks to Ben Jarvis, Biodiversity Manager at IdVerde, for permission to collect specimens from the ponds.

Report and most photographs by Alan Wood, photomicrographs by David Linstead.

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