Disclaimer & Copyright Notices; Optimized for the MS Internet Explorer
In this system, a certain arbitrariness is unavoidable, and the danger exists that the respective categorization is rigidly applied. To avoid this, judgment about allocation of a given lake to a trophic category should not be based on only one or two parameters but on the total information.
The advantage of a fixed boundary system is its easy application by managers and technical personnel with only limited limnological training. In particular, it is apt to prevent gross misuse of the trophic terminology, which has often happened in the past.
Trophic Category (Annual Mean Values) | [P]λ | [chl] | [max. chl] | [Sec]y | [min. Sec]y |
---|---|---|---|---|---|
mg/m3 | m | ||||
Ultra-oligotrophic ..... | ≤ 4.0 | ≤ 1.0 | ≤ 2.5 | ≥ 12.0 | ≥ 6.0 |
Oligotrophic ........... | ≤ 10.0 | ≤ 2.5 | ≤ 8.0 | ≥ 6.0 | ≥ 3.0 |
Mesotrophic ....... | 10 - 35 | 2.5 - 8 | 8 - 25 | 6 - 3 | 3 - 1.5 |
Eutrophic ....... | 35 - 100 | 8 - 25 | 25 - 75 | 3 - 1.5 | 1.5 - 0.7 |
Hypertrophic ....... | ≥ 100 | ≥ 25 | ≥ 75 | ≤ 1.5 | ≤ 0.7 |
We salute the Chebucto Community Net (CCN) of Halifax, Nova Scotia, Canada for hosting our web site, and we applaud its volunteers for their devotion in making `CCN' the best community net in the world