Conservationists say it will take up to a year to know the extent of fire damage to the Kaimaumau wetland.
On the seventh day of the blaze, five helicopters, 25 firefighters, and nine bulldozers and diggers are trying to strengthen containment lines and put out hotspots.
The fire - which has burned through 2000ha of bush, scrub, swamp and dune vegetation - has been contained and did not spread overnight. Peat fires are burning underground in the wetland.
Forest and Bird Northland conservation manager Dean Baigent-Mercer said ecologically, it was a "catastrophic disaster".
A dozen plant species in the Far North township were already on the verge of extinction before the fire, Baigent-Mercer said.
"There are ferns that are really close to extinction, there's a tiny little mistletoe that grows on kānuka, and there are orchids.
"One of the orchids hasn't even been named by scientists yet and there's only one photograph of it in flower, in the world."
The wetland is one of Te Tai Tokerau's "natural wonders", he said.
"There's Northland mudfish, which obviously only live up here. There's Australasian bittern which is now classified as nationally critical, in terms of its closeness to extinction, so it's similar to kākāpō in terms of its numbers.
"There's also the Northland green gecko and there Aupouri gecko and they are really special creatures."
Baigent-Mercer said the fire would have spread too fast for some to escape, particularly nesting birds.
"There's nesting birds in there at the moment as well as all of this other special wildlife. Who knows that's going to remain but it's probably not a good picture at all."
While next year's spring growth would show which species survived, he said the wetland was now at risk of weed invasion.
Forest and Bird expects the ecological damage from the fire will be similar to that of Australian bush fires in 2019.
The blaze was just 200m from some homes and forced some to evacuate, but they were able to return home yesterday.
Fire crews will work through Christmas and New Year to control and mop up the blaze.
Baigent-Mercer said firefighters sacrificing their Christmas to put out the blaze were "national heroes".
Campers will be banned from Kaimaumau these holidays to reduce the risk of further fires, and to prevent evacuation problems.
Fire crews are doing a controlled burn at Kaimaumau to remove 15ha of vegetation, which they hope will remove fuel for wildfires near the seaside village.
RNZ
