Chapter 13 – The Biotic Indices

摘要: Biotic indices have been used to assess water quality since the early twentieth century and thus pre-date first index based on physico-chemical characteristics by about 85 years. The biotic were determined presence or absence of specific indicator species from a number different groups trophic levels (mainly bacteria, algae, protozoans rotifers, but including some benthic invertebrates fish) for which tolerances organic pollution known. Selected components total aquatic community thus, as an degree pollution. Most modern indices, other hand, are organisms sampled particular group, such macroinvertebrates.