A group of Dunedin scientists is closely monitoring a wetland that could be the first in the country to experience changes from sea level rise.
It's south of Dunedin and connected to the Pacific Ocean by the Taieri River.
The area is being studied to discover how much saltwater is starting to mix with the freshwater.
Half an hour from Dunedin and 20 kilometres from the ocean, small streams make up the Te Nohoaka o Tukiauau wetland.
"This is a really significant wetland, it's probably one of the first wetlands in New Zealand that will experience the changes of sea level rise," Department of Conservation (DoC) freshwater technical advisor Chris Kavazos said.
The rising sea level could eventually turn the freshwater to salt water.
"We've got two loggers here, one that measures salinity and one that measures water height," Kavazos said.
"By deploying these loggers and building a big data set we will be able to estimate and predict the futures of the tidal characteristics as sea level change comes up and how those important distributions will shift upstream."
It's crucial for understanding spawning habitats.
"Pre-Europeans this was a massive mahinga kai source, eels, all kinds of galaxiids," Te Nukuroa o Matamata senior ranger Oliver Dawson said.
"As the wetlands change to a saltwater environment we need somewhere for the whitebait, eels and other mahinga kai to go to."
Historically, the wetland has faced multiple threats. Industrial-level drainage decades ago still has an impact today.
"There are multiple pressures affecting the wetlands, including high levels of sedimentation from runoff through harvest cycles and forestry, and runoff from farms, weed incursion, willows have been here a long time," planting and weed control team supervisor Karen Mayhew said.
They're also mapping the change in ground elevation over the last 15 years to analyse how it's kept up with sea level rise.
"We're estimating that by the year 2100 the sea it will be about 80cm higher than it is today," Kavazos said.
There is planting along the stopbanks to prepare. But how the wildlife prepares or adapts will only be known over time.
"The inanga can't handle that much salinity but it could be they slowly evolve to handle that salinity as well. It's a hard one, you're trying to predict climate change and it's very hard to predict," Dawson said.
A place of great historical significance, just as important in the uncertain future.
