Trophic level index (TLI) of Rotorua lakes
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Purpose of indicator
Current information and trend
Table 1. Lake TLI unit values and long term trend.
* Long term trends starting point is year 1900
Source: Bay of Plenty Regional Council, 2011
Lake type referred to in Table 1 is based on the TLI value. Figure 1 below explains different lake types as they relate to water quality (TLI).
Figure 1. Lake types according to TLI values.
- Eight of the 12 lakes show at least possible improvement
- Two lakes show no change
- Two lakes show possible degradation
Long term trends (since 1900)
- Four of the 12 lakes show at least possible improvement
- Three lakes show no change
- Five lakes show possible or some degradation