A fire that started yesterday at Awarua Bay now extends as far as the significant Waituna Wetlands, and increased in size from 1.5 hectares (ha) to over 1000 ha.

Nine helicopters and four ground crews are currently working on the fire which is now burning in peat. Much of the fire ground is difficult to access on foot.

Aircraft and crews were concentrating on containing the fire, to reduce the risk that it could spread further into unburnt fuel.

Incident Controller Mark Mawhinney says they will be on site until dusk but will return at 8am tomorrow with nine helicopters again and eight ground crews.

There will also be heavy machinery to construct fire breaks.

Mawhinney says that the forecast is for a change in wind direction tomorrow, with easterly gusts up to 45 knots.

Fire and Emergency NZ is planning for an extended response with crews likely to be working for a fortnight or more to fully extinguish the deep-seated fire.

Fire and Emergency is liaising closely with Iwi and with the Department of Conservation, which manages the area affected by the fire.

Dean Whaanga, Kaiwhakahaere for Awarua Rūnaka, says that Awarua-Waituna is significant to Ngāi Tahu whānau and to the local community.

"We are thankful for the quick response from Fire and Emergency as they go about protecting this special place and the taonga species that live there."

Awarua-Waituna is one of New Zealand’s largest remaining coastal wetland systems, one of five significant wetlands in DOC’s national Awarai Kākāriki wetlands restoration programme.

It is home to many wading birds and other species.

Awarua Bay Road has been closed to the public and people are asked to stay away from the area.