Source: Department of Conservation

Date:  31 January 2025

The good news comes just ahead of World Wetlands Day, which celebrates and raises awareness of the significant role wetlands play for the planet and people. This year’s theme is protecting wetlands for our common future.

Aotearoa has seven Ramsar-listed wetlands, recognised as internationally significant sites, including Whangamarino Wetland in Waikato.

The October fire burned through about 1000 hectares of the peatland, one of the few remaining raised peatlands in the southern hemisphere. It stores a significant amount of carbon in its soils, and is home to rare native plants and threatened species like the matuku-hūrepo/Australasian bittern and pūweto/spotless crake.

DOC Whangamarino Ranger Lizzie Sharp says thanks to relatively high water levels in the peatland before the fire, only a shallow layer of the peat soils was burned.

“The wetland is showing signs of hope. The peatland areas of Whangamarino were healthy before the fire as it wasn’t being actively drained and had good vegetation cover dominated by native plants, so we’re more confident about its recovery.”

“Although this is great news, the fire has still caused significant damage to the vegetation and upper layers of the wetland, resulting in loss of 1000ha of critical habitat for threatened species. The loss of biodiversity caused by the fire will likely take decades to recover.

It’s like the peat bog has lost its skin. It is still vulnerable and losing water more easily than it should. The new conditions are inviting for weeds like willow, royal fern, and pampas.”

Lizzie says the recovery plan will focus on controlling invasive weeds which will give the native peat vegetation time to recover from their seed sources which survived the fire.

“Peat bog wetlands are normally low-nutrient environments and the plants living there have adapted to those conditions. The firefighting effort used water from nearby waterways which had much higher nutrient levels, so we want to understand how the wetland responds to this.”

DOC Principal Science Advisor Freshwater Hugh Robertson says other peatland fires in New Zealand have emitted more than 200 tonnes of carbon per hectare, but the loss of carbon at Whangamarino is likely to be only about 50-80 tonnes per hectare because the wet peat soils did not burn. However, further research is needed to confirm the carbon emissions.

“Peatlands are great carbon stores because the vegetation in them, which holds the carbon, decomposes very slowly, trapping it. It’s like the vegetation freezes in time.

“However, peat soils are highly flammable, particularly when they’re dried out. Re-wetting our wetlands will make them less susceptible to the impacts of fires which in turn will reduce greenhouse gas emissions,” Hugh says. 

World Wetlands Day, celebrated annually on 2 February, dates back to 1971 when environmentalists gathered in the city of Ramsar, Iran, to reaffirm protection for our world’s wetlands.

The day highlights the influence and positive production wetlands have on the world and brings communities together for the benefit of wetlands. It also raises global awareness of the significant role wetland’s play for the planet and people.  

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