The macroinvertebrate module is used to assess streams based on their colonisation by small of bottom-dwelling invertebrates. This includes insect larvae, small crustaceans, snails, bivalves and worms. These animals react differently to environmental factors such as temperature, water quality and structural habitat diversity of of streams. The Swiss Macroinvertebrate Index IBCH_2019 indicates deficits, particularly in water quality and structural habitat diversity.
What is assessed:
A rough determination of the macrozoobenthos in the stream reach is used to assess whether its community is close to natural and appropriate to the site, and whether the diversity of organisms corresponds to that of only slightly impaired streams. Based on these results, conclusions can be drawn about the condition of the stream.
Benthic macroinvertebrates, mainly at the family taxonomic level or at coarser taxonomic levels (e.g. for oligochaetes).
The IBCH is based on:
- the taxonomic diversity (VT)
- the indicator group (GI)
The evaluation is done in five quality classes.