Page 105 - Freshwater-Biology-and-Ecology-Handbook

10

COLLECTING

FIELD DATA

Invertebrate samples should always be accompanied
by observations made in the field to help interpret
the invertebrate data, in addition to the field
measurements necessary for RIVPACS (Section 7.6).
This includes observations about the presence of rare
or invasive species, the physical structure of the site
and surrounding land use, the habitats present, any
indicators of pollution or physical degradation and any
difficulties collecting the sample, particularly if they
could affect its quality.

Photographs are most useful and should always be taken
when invertebrate samples are collected. Concentrate on the
surroundings to put the site into context when photographing
sites. Photographs that concentrate on the water surface without
the surroundings do not convey much information. Underwater
photographs taken with waterproof cameras on the end of a
pole (such as a pond net handle) that show the condition of the
riverbed are also particularly useful. These photographs should
be stored electronically to help interpret any changes observed
in the river invertebrate data. Photographs are always useful and
are often vital in reports.

Larger rare species of invertebrates must be recorded in the
field and returned to the site immediately. This includes animals
such as the medicinal leech, native white-clawed crayfish, and
pearl mussels. Amphibians and fish should also be recorded and
returned immediately.

Water chemistry measurements taken by simple hand-held
meters are also useful, particularly pH, conductivity, temperature,
and oxygen concentration. Electronic field meters must be
calibrated periodically, to ensure that they remain accurate.

This supplementary environmental information is useful for
interpreting your results, even if it is not to be analysed using
RIVPACS tools.
River Piddle (Site P4) at Hyde SY 86475 90639 15 JUL
2015 Austropotamobius pallipes (Native Crayfish)
(Specimen returned to river) John Davy-Bowker

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