Reborn to be wild
Wildlife haven in rehabilitation of state-owned land
BROTHERS Rodrick King, 3, Ezekiel King, 5, and Johnny King, 4, fish off the beach at East Trinity – an area which has been transformed over the past couple of decades from an acidic wasteland to a natural treasure and a haven for wildlife.
IT once had soil so acidic, mangrove trees withered up and died and countless fish were killed, but East Trinity has now been transformed into a natural jewel of Cairns.
A new report detailing the environmental rehabilitation efforts during the past two decades at the 774ha area across Trinity Inlet has described the suburb-sized block of stateowned land as a haven for wildlife, including large crocodiles.
It comes as Cairns Regional Council last week granted approval to the Mandingalbay Yidinji Corporation to develop a $39 million indigenous tourism venture in the area with zip lines and overnight accommodation.
State Environment Minister Leeanne Enoch said the scientific processes used to transform the one-time sugar cane farm, purchased by the Queensland Government 18 years ago, were being seen as a benchmark for rehabilitating acid sulphate soils.
“During the site’s transition to a sugar cane farm, a large 7km bund wall was constructed to prevent the natural flow of tide,” she said.
“Because of this, previously waterlogged soils were exposed to air, resulting in a chemical reaction where sulphuric acid was released at a level of acidity equivalent to battery acid.
“Acid water leaked from the soil into the waterways – along with large quantities of iron, aluminium and other metals, resulting in fish kills and the death of mangrove forests.
“The sugar cane production also failed and the soils and waters became severely degraded.”
The report, released on Friday, shows how scientists introduced lime to the tidal waters to neutralise soil acidity, at a cost of up to $80 million.
Almost 20 years later, scientists have reported this process has stabilised the acidity in soil and waterways, creating a healthy intertidal wetland system.
The report’s authors state that much of the mangrove forests that died out have since returned and birdlife has returned to the habitat.
They also said sightings of large crocodiles were “becoming more frequent as healthy communities of fish and crustaceans are re-established under lime-assisted tidal exchange”.
Cairns and Far North Environment Centre president Denis Walls, who helped campaign for the restoration of East Trinity in the 1990s, said rehabilitation efforts needed to be ongoing.
“The report means that the future of East Trinity is solidly environmental, with some small-scale commercial opportunities,” he said.
“It will mean, ultimately, that if the Mandingalbay Yidinji proposal goes ahead, that East Trinity can become the half-day trip from the CBD that I have been talking about for so many years, without the recurring talk of tunnels, bridges, satellite cities and dump spoil sites.”