Wetlands support many taonga species, improve water quality, help prevent flooding, reduce the effects of drought, and are highly valued by Māori as a source of mahinga kai, traditional materials, and medicines.
These important ecosystems once covered approximately 258,451 hectares of Taitokerau – 32 percent of the land area. Today, only around 5% percent, or about 14,000 hectares, of the original wetland area remains.
The new maps can support kaitiakitanga, planning, and management decisions, and help to monitor how wetlands are changing over time. They can also be used to identify opportunities to protect and restore wetlands and to help target funding and support for landowners.
However, Policy Specialist James Griffin says the maps have limitations and won’t be used for regulatory monitoring, enforcement, or to determine whether rules about wetland management apply.
“The new maps give a helpful indication of where wetlands are likely to be, but they’re not sufficient on their own for regulatory or legal decisions,” he says.
The maps were created using high-quality aerial imagery, predictive modelling and machine learning, and LiDAR (remote sensing technology that uses lasers to create 3D maps). Data from these sources are combined to predict where wetlands are likely to be and how extensive they may be.
“Using this technique, we’ve been able to identify over 100,000 potential wetlands, many of which weren’t previously recorded. These new maps include small wetlands that have previously been underrepresented or unmapped,” says James.
The Tangata Whenua Māori Advisory Committee (now Te Ruarangi) and Māori Technical Advisory Group guided data accuracy and validation, appropriate use, public access to information, data sovereignty, and protection of sites of significance. The maps do not identify sites of significance or cultural values associated with wetlands.
The maps cover different types of freshwater wetlands, including swamps; gumlands (wet heathlands); bogs; fens; marshes; ephemeral and seepage wetlands; and some river, lake and stream margins. They also show saltwater wetlands, such as saltmarshes and mangroves.
James says the new wetland maps meet national requirements for Northland Regional Council to map and monitor wetlands.
With only a few fragments of Northland’s original wetlands remaining, better understanding and management can’t come too soon.
New mapping is helping build a clearer picture of where Taitokerau wetlands are found, and how they can be protected for the future.
