Estuarine and catchment characteristics.

Data obtained from the New Zealand Estuarine Environment Classification Database [35].
Estuarine water area at high tide and land catchment area in km2. Shore length in km. The shore complexity index (SC) as the length of the perimeter of the estuary shoreline divided by the circumference of a circle that has the same area as the estuary (1 simple and <0.1 complex shoreline). The closure index (CI) as the width of the estuary mouth divided by the length of the perimeter of the estuary shoreline (0.4 wide to <0.01 narrow entrance). Annual river inflow as the ratio of river inflow to total estuary volume at high water. The mean annual discharge of river to estuary in cumecs. Mean catchment rainfall (mm/yrs) and mean annual runoff (mm/km2). Mean tide range in metres. Intertidal, as the percentage of intertidal area in the estuary at high water. Land-use variables based on the percentage of catchment covered by natural, pastoral and exotic vegetation and urban areas.