Warnham Local Nature Reserve excursion

Saturday 3rd August 2024

This was the thirteenth Quekett excursion to Warnham Local Nature Reserve on the outskirts of Horsham, West Sussex, hosted by the Friends of Warnham Local Nature Reserve, and organised by Graham Matthews. As last year, we set up our microscopes,  cameras and computers in a small room at the side of the Discovery Centre.

Discovery Hub

The new reed bed just outside the Hub is now well established, so that was the first place we sampled, using collecting jars and a plankton net with long handles.

Neil Henry sampling the reed bed

Graham Matthews sampling the reed bed

Reed bed

Reed bed sample

There was a lot of filamentous algae in the samples from the reed bed, and a few diatoms, rotifers and nematodes, but hardly any waterfleas.

Then we went further into the Reserve to take samples from the three dipping ponds, all of which have wooden platforms for easy access. The floating plants include water lilies and Potamogeton; other plants include horsetails and reeds.

Graham Matthews pond dipping

Graham Matthews checking the catch

Dipping pond samples

We found a lot more in the samples from the dipping ponds, including mosquito larvae and pupae, midge larvae, mayfly nymphs, a water mite, freshwater shrimps (probably Crangonyx), small snails, hydra, copepods (including nauplius larvae), Cladocera, testate amoebae, cyanobacteria, rotifers, diatoms, euglenoids, ciliates and filamentous algae. Graham used lidocaine hydrochloride to slow down some of the specimens and make it easier to photograph them.

Plankton nets help to concentrate specimens into the small jar sat the bottom of the net. A handle that is telescopic, or has multiple sections, is useful for extending the reach.

Plankton net

Some golf-ball retrievers can hold a small jar securely, so that it can be dipped upside-down into water at any depth, and then turned over to fill with water. A telescopic handle makes it easier to carry around.

Collecting jar

We used pipettes to transfer specimens from the jars into small white trays, and from there onto plain or cavity slides.

Neil Henry brought his monocular PZO microscope, fitted with 4×, 10×, 20× and 40× objectives and a PZO light source that Graham modified to use an LED. Instead of a microscope eyepiece, Neil uses a YW5.0M eyepiece camera sending images to S-EYE software on his laptop computer.

Neil Henry

Alan Wood and Neil Henry [By Graham Matthews]

Graham Matthews brought his trinocular Leitz Dialux microscope with 16×, 25× and 40× NPL Fluotar objectives for DIC, plus an EF 10× objective and a 1.6–5× Zeiss zoom objective. He uses an Asahi Pentax microscope adapter with a Zeiss Kpl 8× eyepiece and a Tominon 1:4.5 f=50 mm copy lens to connect a Canon EOS 500D digital SLR. The camera is controlled by DSLR Remote Pro on his laptop. He uses Helicon Soft to stack images to increase depth of field.

Everyone passing through the Herons Rest Café to reach the Reserve had to pass the door of our room, so we had a number of visitors, some adults and some families with young children.

Graham Matthews with visitors

Graham Matthews photographing Spirogyra

Luke Whitehouse and Clare Blencowe dropped in for a chat, and Clare came pond dipping with us.

Graham Matthews and Clare Blencowe

Luke Whitehouse [By Graham Matthews]

Graham has adapted his Leitz Dialux to use both LED and electronic flash illumination, by using a dual fibre optic bundle that (just by chance) fits perfectly where the original halogen light source was. He has modified a Vivitar 283 electronic flash so that he can use resistors to vary the flash duration. One arm of the fibre optics collects the flash output, and the other arm provides light from an LED.

Vivitar 283 outputting to fibre optics

Leitz Dialux with dual fibre optics input

Photomicrographs

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 the Friends of Warnham Local Nature Reserve for allowing us to collect specimens and to use the Discovery Hub, and to Graham Matthews for organising the excursion.

Report and most photographs by Alan Wood, photomicrographs by Graham Matthews.

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