Fire toll at Awarua-Waituna wetland unknown

It could be weeks before conservationists know how significant the biodiversity loss is at Awarua-Waituna wetland, as fire continues to destroy the area. So far more than 1300 hectares of mānuka scrub and peat have been burned through since April 2. 

The wetland, east of Bluff, near Invercargill, is one of the largest remaining wetland complexes in New Zealand, and was the first to be considered of international importance. It’s home to 81 bird species, including 21 migratory birds who rest there on their journey north of the equator. Native fish found there include the giant kokopu, banded kokopu, inanga, eels and lamprey, and different types of lizards and insects also make it their home. Rare and endangered flora associations such as cushion bog grow there. 

The fire is releasing “massive amounts” of greenhouse gases into the atmosphere, says Conservation Minister Kiritapu Allan. Photo credit: Southland Fire & Emergency

This is the third major fire at the site since 1986, each blaze progressively changing the vegetation and setting back the natural succession process. 

Environment Southland says flora and fauna losses from this latest inferno could be potentially devastating.

“Significant flora and fauna populations will have been damaged,” agrees Boffa Miskell ecologist, Dr Sarah Flynn, ”less mobile species like fernbird (mātātā) and lizards, in particular, will have high mortality as a result.  In addition, because these ecosystems are so reduced and fragmented, they lack the resilience that they ought to have in terms of there being other parts of the landscape that have all these populations in them that can then recolonize.”

The cost of fighting the fire has been estimated at around $800,000. Photo credit: Southland Fire & Emergency

Peat wetlands are also super carbon sinks, holding twice as much carbon as all of the world’s forests combined, even though they only cover about three percent of the earth’s land surface. 

“These kinds of wetlands are pretty special in that they contain a lot of carbon,” Dr Flynn says. “This is the beginning of the carbon sequestration that ultimately turns into fossil carbon. But when it burns, all that carbon goes into the atmosphere. That’s just reversed thousands of years of sequestration in a couple of days. So that’s a bit of a catastrophe.”

There are areas of deep pits of burning peat soils. These areas are not obvious, but they can reach temperatures of up to 300’C, making them extremely hazardous to humans and animals. Photo credit: Southland Fire & Emergency

Dr Flynn says peat fire risks increase after extended droughts, and because of climate change New Zealand is experiencing more droughts. While the previous two fires at Awarua wetland were caused by human activity, it’s not yet known how this one started.