The richness of benthic macro-invertebrate species is used to monitor the overall health of stream ecosystems in Gwaii Haanas. Any shifts in community composition, initially detected as an increase or decrease in species richness, can be the result of nutrient levels, atmospheric pollutants, or a physical disturbance of the habitat. This is the result of species adapted to the new conditions increasing in abundance and species maladapted to the new conditions decreasing in abundance. Streams are sampled in permanent locations on a 3-year rotational panel monitoring design. This data is also posted to, and available from ECCC's CABIN database.