Page 131 - Freshwater-Biology-and-Ecology-Handbook

Steps in the STAR-AQEM method are as follows:

• Before entering the water, complete the STAR-AQEM site protocol forms, which cover site
assessment and field data, available from Annex 2 of the AQEM manual.

Based on the microhabitat list given on page 2 of the site protocol (Figure 2.26), the coverage of all
microhabitats with at least 5% cover is recorded to the nearest 5%, from which the number of
replicates in each of the individual habitats is determined.

• Start sampling at the downstream end of the reach and proceed upstream. Use a hand net either
as a kick net, or for ‘jabbing’, ‘dipping’ or ‘sweeping’, or use a Surber sampler.

• After every three replicates (or more frequently if necessary) rinse the collected material in clean
stream water two to three times. If clogging occurs, discard the material in the net and redo the
replicates in the same habitat types but at different locations.

• Remove large wood and stones after rinsing and inspecting for clinging or sessile organisms,
which should be placed into a sample container. Do not spend time inspecting small debris in the field,
although larger and fragile organisms (eg Ephemeroptera) or species that cannot be preserved
(eg Tricladida, Oligochaeta) should be partly sorted in the field. Store these organisms in a separate
small container.

• Remove large and rare organisms that can be identified in the field, such as large mussels, and
return them to the stream after recording their presence.

• Immediately after collection, transfer the sample from the net to sample container(s) and preserve
with enough 95% ethanol to cover the sample after decanting any water from the sample, to prevent
carnivores from eating other organisms. The final ethanol concentration should be about 70%.

Close the sample container tightly. The samples should be stored cool. Alternatively, for live sorting in
the laboratory, the samples must be kept in a minimum amount of liquid and transported immediately
to the laboratory. They must be kept cool during transport.

• Labelling: Place a label (written in pencil, printed on a laser printer or photocopied) inside the sample
container.

• Refine the site protocol, particularly the share of microhabitats, after sampling has been completed,
when you will be able to provide a more accurate assessment.

• Sample processing is described in the STAR revision of the AQEM protocol. Only a portion of the
sample needs to be analysed. Methods for splitting the sample are provided in the STAR document
and the CEN standard on pro rata sampling, mentioned earlier. Only the first 700 organisms need to
be analysed, so further sub-samples do not need to be taken after this number is reached.

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