From: Integrated approach to the understanding of the degradation of an urban river: local perceptions, environmental parameters and geoprocessing
Category
Trophic State Index (TSI)
Ultraoligotrophic
TSI ≤ 47
Oligotrophic
47 < TSI ≤ 52
Mesotrophic
52 < TSI ≤ 59
Eutrophic
59 < TSI ≤ 63
Supereutrophic
63 < TSI ≤ 67
Hypereutrophic
TSI > 67