Trends assessments are estimated at each site using monthly data over periods of 5-, 10-, and 15- years, where sufficient data is available. These results are then categorised into differing levels of trend direction likelihood seen on the legend in the maps below. Site-periods with too few data for reliable estimates of both direction and rate are shown as “not assessed”.
The trend methodology follows the approach as described in this LAWA trends factsheet with exceptions:
State assessments are included where applicable in the map hover labels and tables. See the state assessments results page or methods page for full details on acronyms and criteria. Note Lake Ōnoke NOF & NRP states are only included for when the lake mouth was open at the time of sampling. 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 variables, drag and scroll on the maps to move and zoom in, toggle the top right “Trend period” control on the map to switch between different length periods if available. Specific values and classifications can be seen by hovering over the arrows and circles on both the map and table. Click on table headers or the arrows next to them to sort the data by that column – holding the shift key allows sorting over multiple columns.
All values are mg/L unless otherwise noted.
All values are mg/m3 unless otherwise noted.
All values are mg/m3 unless otherwise noted.
All values are metres (m) of visibility underwater unless otherwise noted.
All values are mg/m3 unless otherwise noted.