Macroinvertebrate Community Index (MCI)

MCI stands for Macroinvertebrate Community Index which is an index where macroinvertebrates are used for monitoring and reporting on stream health in New Zealand. The MCI assigns a score to each species or taxon (from 1 to 10), based on its tolerance or sensitivity to organic pollution, then calculates the average score of all taxa present at a site. It is a qualitative sampling method, which means it will tell you which species are present or absent in your sample. If you want to know the abundance (i.e., how many) of a certain species are in your sample, you will need to use the Quantitative MCI (QMCI) sampling methodology.

View a factsheet on Benthic macroinvertebrates