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How to collect a plankton sample

Due to Covid we are not at sea, the demonstration shown here shows a sample of water being taken from a river.  A similar procedure may be used for taking a sample at sea. You can also take a sample of water from your municipally supplied drinking water or even bottled water.  It is likely you will find micro-plastics and fibres from all of the sources.

It is important not to cause contamination of the water sample, so try and avoid wearing clothes such as a fleece that sheds many particles.  Probably not a good idea wearing a fleece in any case,  because you will be breathing in plastic from your clothes.

Make sure you always follow the washing process, we want to try and avoid any contamination which would lead to false readings.


1. Dismantle the filter and wash it in the water, you may use the seawater of river water.

2. Wash the tweezers and then use them to carefully lift out just one filter paper. It's easy to lift two by mistake, so make sure it is just one. A place it over the 25mm hole in the lower section of the filter.

4. Take the top section of the filter and place on the bottom section, make sure it is central. Push the assembly down on a flat surface, lift up the ring and screw the bottom and top sections together, making sure that it is only the ring that rotates.

5. Suspend or hang the filter from the two holes, use a wire of light chain. Try to avoid cord, because micro-filbres may come off and contaminate the sample.

6. Wasj the sample collector in the water, and then take a water sample in excess of 0.5 litres, and pour into the suspended filter until the water over-flows. There is now 0.5 litres in the filter.

7. Water will begin to pour out of the base of the filter, this will continue for up to 60 minutes, depending upon the number of plankton and solid particle concentration in the water sample. Also if you use two filter papers instead of one, it will take over 1 hour to filter the sample. 

8. After one hour, take the filter apart and carefully remove the filter paper using the tweezers.  Place a 60mm 5mm squared plastic paper disc into the 90mm petri plate, and place the filter paper over the 60mm squared disc.  Try and line it up as well as you can, using the tweezers

9. You can now view the filter paper under a microscope.



Life on earth depends upon healthy Oceans, we have 10 years to stop toxic chemical pollution, or life on earth may become impossible

Dr. Howard Dryden, CSO

Goes Foundation

Roslin Innovation Centre
The University of Edinburgh
Easter Bush Campus
Midlothian EH25 9RG