Procedure:
• Gently remove the tray from the stream bed moving it downstream with the current as
you lift it up. Warning: the trays are very heavy when full of water.
• Keep the tray close to horizontal while draining, especially if there is any chance of
material becoming detatched from the filter papers.
• When the sampler starts to clear the water, take a note of anything that might influence
the periphyton communities and thus effect interpretation of the results. Write these
down once on the river bank. Things to observe might include the amount of silt
accumulated on the slides or substrates, any debris such as leaves, twigs or macrophyte
stems that have caught on the sampler and might have brushed against the sampling
surfaces or influenced local flow paths.
• Count any invertebrates on each filter paper to the lowest taxonomic level that you can
Stream Periphyton Monitoring Manual
• Fold the filter paper and sample in half (upper sides together).
• Clean off any periphyton growing on the underside of the filter paper with a soft
toothbrush and discard.
• Fold the paper again, or roll up loosely, and place the whole paper in an appropriately
labelled container.
• Put the 20 containers for each tray into a separate plastic bag – this greatly simplifies
sorting out back in the lab.
• Transport the bag of samples back to the lab for analysis as quickly as possible. In the
meantime, keep them frozen, if at all possible; otherwise keep them in a cool dark
place.