Mangroves ‘died of thirst’, says JCU
A James Cook University scientist has discovered why there was an unprecedented dieback of mangroves in the Gulf of Carpentaria in early 2016 – the plants died of thirst.
Dr Norman Duke, leader of JCU’s Mangrove Research hub, headed an investigation into the massive mangrove dieback. The scientists used aerial observations and satellite mapping data of the area dating back to 1972, combined with weather and climate records.
Dr Duke said they found three factors came together to produce the unprecedented dieback of 7400 hectares of mangroves, which stretched for 1000 kilometres along the Gulf coast.
“From 2011 the coastline had experienced below-average rainfalls, and the 2015-16 drought was particularly severe. Secondly the temperatures in the area were at record levels and thirdly some mangroves were left high and dry as the sea level dropped about 20cm during a particularly strong El Nino.”
Dr Duke says this was enough to produce what scientists regard as the largest recorded incident of its kind, and the worst instance of likely climate-related dieback of mangroves ever reported.
“Essentially, they died of thirst,” he said.
Dr Duke said scientists now know that mangroves, like coral reefs, are vulnerable to changes in climate and extreme weather events.
Indigenous ranger monitors mangrove dieback along the Gulf of Carpentaria coast