Almost half of Cairns Airport’s landholdings is coastal forest, most of which is mangrove wetlands. For the first time at this scale, a partnership between Cairns Airport, Dawul Wuru Aboriginal Corporation, and Deakin University’s Blue Carbon Lab is investigating just how much work these tropical mangrove ecosystems are doing to mitigate the impacts of climate change. 

‘Blue carbon’ is carbon that has been captured by the world’s blue oceans and associated coastal ecosystems, including mangroves, wetlands, saltmarshes, seagrass beds and algae forests.  

Along the coastline of tropical north Queensland, mangrove wetlands trap sediments running off the land and prevent them from washing onto the Great Barrier Reef, locking up carbon and building a living carbon sink in the process. These vast mangrove forests continue to suck carbon dioxide from the atmosphere and store carbon and greenhouse gases below ground for thousands of years.   

Cairns Airport Environment Manager Lucy Friend says the region’s tropical mangrove ecosystems are understudied.  

“This work will help us better understand blue carbon in Australia’s tropical mangroves, and it will also help to calibrate blue carbon models for similar mangrove forests further north.   

“Mangroves are important all around Australia’s coastline but we suspect that national averages don’t do our mangroves justice. Above ground, we can see that the trees are a lot taller than down south, and the species diversity is much higher. Below ground, we know the mud is 10 – 12 metres deep in some areas, and that new forests are being built really quickly, using carbon as the building blocks.”  

The 350 hectares of mangrove wetlands at the airport are almost as big as the airport’s operational area and are managed in partnership with Dawul Wuru Aboriginal Corporation’s Land & Sea Ranger group. 

Yirrganydji Senior Ranger Brian Singleton says the research will give everyone a better understanding of how much carbon the area is sitting on.  

“These mangroves are typical of what you’ll find the whole way through the Cape and the Gulf,’’ he says. “It means the research will also be useful to other ranger groups in those regions that are managing mangrove areas. 

“It will let us know the potential for income streams through carbon credits, as well as help to protect mangroves. Their value isn’t limited to carbon storage and sequestration – they have important cultural values too”. 

The public can view tropical mangroves by visiting the mangrove boardwalk off Airport Avenue. Cairns Airport and Dawul Wuru Aboriginal Corporation have taken over management responsibilities of the boardwalk after council closure in 2019.