Australian mangroves died of 'thirst'

A staggering 7400 hectares of mangroves died of "thirst" in an unprecedented wipeout of the coastal shrubs in northern Australian in 2016, say Queensland scientists.

A study by James Cook University's Mangrove Research Hub, published in the Journal of Marine and Freshwater Research on Tuesday, said it was the worst instance of climate-related mangrove dieback on record.

Dr Norman Duke, one of the lead researchers, said they had studied aerial observations and satellite mapping of the area back to 1972, combined with weather and climate records.

The research identified three factors that led to the dieback along the 1000 kilometre stretch of the Gulf of Carpentaria.

Below average rainfall, culminating in a severe drought in 2015-16, along with record high temperatures and water levels that dropped 20 centimetres led to the destruction.

"Essentially, they died of thirst," Dr Duke said.

He said global scientists would monitor the response because mangroves and coral reefs are both vulnerable to changes in the climate.

"So the relative dominance of climate influences in this region is of critical interest to world observers of environmental responses to climate change," Dr Duke said.