Page 129 - Freshwater-Biology-and-Ecology-Handbook

STAR-AQEM samples are standardised by
sampling a fixed area of 1.25 m2.

A sample consists of 20 sub-samples taken
from all microhabitat types at the sampling site
with at least 5% coverage.

A sub-sample is collected from a 0.25 x 0.25m
square quadrat. The 20 sub-samples are
allocated to microhabitats according to their
proportional cover. For example, if the habitat in
the sampling reach is 50% sand, 10 of the sub-
samples must be taken from this microhabitat.
See Figure 2.23.

Figure 2.23
Example of the location of sub-samples in a theoretical sampling site according
to the STAR-AQEM ‘multi-habitat sampling’ method (From AQEM manual, 2002)
(16)
In contrast, a RIVPACS sample is standardised
by sampling for a fixed amount of time:
3 minutes + 1-minute search, supplemented in Surber sampler Hand net
deep waters by a 1-minute marginal sweep.

For STAR-AQEM, the sampling site is a 500m
stretch. A RIVPACS site is much shorter. The
nets used to collect STAR-AQEM samples
are 500 μm mesh whereas nets for RIVPACS
samples are 1 mm. In this aspect, STAR-AQEM
may provide more differentiation between
the habitats sampled, which may allow more
detailed analysis in some cases.
Sampler frame:
Much of the rest of the STAR-AQEM procedure 25 x 25 cm
is the same as RIVPACS. Although more
material is collected by the STAR-AQEM
method than RIVPACS, the amount of material
analysed in the laboratory and the number of Figure 2.24
animals identified is similar. Surber sampler and hand net used to collect AQEM-STAR samples
(From AQEM manual, 2002)

Figure 2.25
Sample splitter used to sub-sample a STAR-AQEM sample so that
just over 700 animals are analysed (From AQEM manual, 2002)

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