Full details on each assessment framework and calculations are available in Hickson-Rowden and Perrie (2018) and the state assessments methods page. Data presented are chlorophyll a (mg/m3; measure of phytoplankton volume), Secchi depth (m; metres of visual clarity), total nitrogen (mg/m3), ammoniacal nitrogen (mg/L), and total phosphorus (mg/m3)
Usage: Switch tabs below to look at different states, drag and scroll on the maps to move and zoom in, hover over map circles to see specific values and use the top right toggles on the map to switch between different state periods and sub-components. Click on table headers to sort the data by that column – holding the shift key allows sorting over multiple columns.
The Trophic Level Index (TLI) measures water quality status of New Zealand lakes using four variables; chlorophyll a, Secchi depth (water clarity), total phosphorus and total nitrogen. The map shows the overall mean TLI score for each lake and the table includes each of the four TLI variables. These values are calculated for the periods July 2022 to June 2023 and the three-year rolling mean period July 2020 to June 2023 (note the variable number of samples between sites). Abbreviated trophic level classes are provided in brackets.
Comparison of lake data against NRP outcomes for the one-year period July 2022 to June 2023. Note Lake Ōnoke data is assessed separately when the lake mouth was open versus closed at the time of sampling; only data for when the lake mouth is open is presented on the map.
Values with asterisks (*) indicate exceedances of NRP thresholds.
Comparison of lake data annual summaries against NPS-FM NOF attribute states for the one-year period July 2022 to June 2023. Individual NOF attribute states are provided in brackets with the overall band shown on the map. Where there are multiple attributes for Chlorophyll a and ammoniacal nitrogen, the worst state determines the overall band. Note Lake Ōnoke data is assessed separately when the lake mouth was open versus closed at the time of sampling; only data for when the lake mouth is open is presented on the map.