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A wetland is land saturated with water, either permanently or seasonally, that supports ecosystems of plants and animals adapted to wet conditions (LAWA, n.d.).
We report on wetland area in Aotearoa New Zealand in 1996, 2001, 2008, 2012, 2018, and 2023 based on data from the New Zealand Land Cover Database version 6.0 (LCDB v6.0).
In this indicator, wetlands were identified using a combination of the wetland variable (or flag) present in the data (based on LCDB v6.0) and land cover classes. When a wetland changes, we show the conversion of the underlying land cover, which can provide insights into the drivers of change.
Land cover in New Zealand is described using three indicators: Indigenous land cover, Exotic land cover, and Urban land cover.
Definitions and metadata has more information about this indicator.
Key findings
Aotearoa New Zealand's wetland area (freshwater and saline) continued its long-term decline, decreasing by 6,994 hectares between 1996 and 2023.
Saline wetlands were identified as areas with mangrove or herbaceous saline vegetation land cover. Freshwater wetlands were all other areas with a wetland flag in the data (based on LCDB v6.0).
| Year | Freshwater wetland | Saline wetland |
| 1996-2001 | -1224 | -71 |
| 2001-2008 | -1714 | -65 |
| 2008-2012 | -1592 | -63 |
| 2012-2018 | -1616 | -69 |
| 2018-2023 | -537 | -113 |
Freshwater wetlands
In 2023, 83 percent of all wetlands were freshwater wetlands.
Between 2018 and 2023, New Zealand's freshwater wetland area decreased by 537 hectares, the smallest decrease in a period since 1996.
Between 1996 and 2023, New Zealand's freshwater wetland area decreased by 6,641 hectares. Of this wetland area, 94 percent was indigenous land cover in 1996.
By region
Freshwater wetland area decreased in:
- 11 of 16 regions between 2018 and 2023
- 15 of 16 regions between 1996 and 2023.
The largest decreases were recorded in Southland and the West Coast:
- Southland had a decrease of 175 hectares between 2018 and 2023, and 2,913 hectares since the 1996 survey period.
- The West Coast had a decrease of 173 hectares between 2018 and 2023, and 978 hectares since the 1996 survey period.
Saline wetlands
In 2023, 17 percent of all wetlands were saline wetlands.
New Zealand's saline wetland area decreased by 356 hectares between 1996 and 2023, and 113 hectares between 2018 and 2023.
Why it is important
Wetlands support high levels of biodiversity and contribute vital ecological functions. They are considered taonga by Māori. Wetlands provide habitat and breeding grounds for taonga species including indigenous invertebrates, plants, fish (for example, kōkopu and tuna (eels)), and bird species (for example, mātātā (fernbird)). Many of these species live only in wetlands. Wetlands act as 'kidneys' and giant sponges - they clean the water of excess nutrients and sediment, control floodwater and pollutants, and act as carbon sinks (removing carbon dioxide from the atmosphere). Wetlands have strong cultural, economic, and spiritual importance for Māori. They are a key source of mātauranga (knowledge), material and resources for mahinga kai (traditional food resources), rongoā (traditional Māori medicine), raranga (weaving), and whakairo (carving).
Where this data comes from
Manaaki Whenua - Landcare Research Group, Bioeconomy Science Institute
Definitions and metadata
Land cover: Data to 2023 - Datainfo+ provides information on the methodology, metadata, and references supporting these statistics.
New Zealand's environmental reporting - Datainfo+ gives supporting information on other Environmental indicators Te taiao Aotearoa.
Topics for environmental reporting outlines the 'Freshwater ecosystems and habitats' topic, of which wetland area is a direct measure.
Related indicators
Indigenous land cover: Data to 2023
Exotic land cover: Data to 2023
Urban land cover: Data to 2023
Related content
Wetlands - Department of Conservation
Wetlands - Bioeconomy Science Institute
Land Cover - Land Air Water Aotearoa
Archived pages
Archived November 2025:
Wetland area - published December 2021
