Earlier this year, scientists were puzzled by a widespread die-off that seemed to plague over 17,000 acres of mangroves along Australia’s northeastern and northern coastlines. Now, a scientist from James Cook University has confirmed that the die-off is likely a product of unusually dry weather and climate change.
“We have seen smaller instances of this kind of moisture stress before, but what is so unusual now is its extent, and that it occurred across the whole southern gulf in a single month,” Norm Duke, a research professor at the university, said in a press release. “What we are seeing is a natural process, but nature usually does this incrementally. Not with such severity. We have never seen this before.”
We have never seen this before.
Surveys from above the ground show that the die-off has affected more than nine percent of the mangroves in a stretch larger than 400 miles west of Normanton, Queensland, along Australia’s northeastern coast.
The mangrove population in Australia is the third largest in the world after Indonesia and Brazil, according to Mangrove Watch, a monitoring program for mangroves. It represents around 6.4 percent of the world’s mangroves. In the states where the die-off is occurring, there are at least 20 different species of mangroves.
The loss of a mangrove population can result in a loss of environmental benefits that people might not realize they were getting from the mangrove forests, Duke told ThinkProgress. Three important benefits include fishing, shoreline protection, and carbon storage.
Mangroves can store at least five times more carbon than terrestrial trees, according to Duke, who is also a spokesperson for the Australian Mangrove and Saltmarsh Network. Essentially, every mangrove that is lost is the same as losing five trees which typically grow inland, which means that losing even a few hundred mangroves can have an exponential effect on natural carbon storage.
Scientists Plead With Australia To Get Off Coal To Save The Great Barrier ReefClimate by CREDIT: AP/PRNewsFoto/Austral Islands of French Polyn Coral reefs around the world are in a dire predicament…thinkprogress.orgQueensland just suffered its fourth failed wet season, with much of the state reporting record-low lower layer soil moisture in 2015. The state suffered from below-average rainfall and some locations with record-low annual rainfall. A majority of the state — 84 percent — was in a drought as of May, and even a downpour in June wasn’t enough to pull the state out of a drought. There has been so little rain that one family relocated 700 cattle over 1200 miles from their property, which has been in a drought since 2013.
The mangrove die-off is likely caused by the extended dry season, according to Duke.
“By all accounts, the climate is going to become more erratic, so we can expect these type of events to become more common,” he said in the press release.
While preliminary signs seem to place blame for the die-off on the dry season and climate change, researchers will now begin working toward pinpointing the exact cause — whether it’s lack of rainfall, high temperatures, pollution, or something else. A project currently in the works to help find these answers is a program called ShoreView, a project of Mangrove Watch.
Duke describes it as Google’s street view for coastlines. This program would make it easier for researchers to monitor changes of the mangrove forests without having to travel across hundreds of miles of coastline. It will help monitor current changes (like the most recent die-off) and expected changes in the future due to climate change.
The State Of The World’s Coral Reefs Is Getting DireClimate by CREDIT: Bernardo Vargas-Angel/NOAA via AP Warmer-than-usual waters have been causing major stress for corals…thinkprogress.orgBuilding a better relationship with indigenous community members to help record this information is crucial, Duke added. Mangrove Watch, which has partnered with TropWATER Centre, has already collected data and trained over 500 people to gather low cost HD video and GPS data, according to a 2013 report. Eventually, the online coastline viewer will be free for public use.
The mangrove die-off is not the first ecological disaster Australia has recently faced. Mass coral bleaching has affected 93 percent of the Great Barrier Reef as of April. Higher ocean temperatures cause the bleaching, and if temperatures remain high for an extended period of time, the bleaching can cause the coral to die.
In June, religious leaders released an open letter ahead of the 2016 elections in Australia. The letter chastised the government for approving new coal mines shortly after signing the Paris Agreement. It also cited the recent degradation of the Great Barrier Reef, and with “great sadness” recognized the “irretrievable loss of parts of the Reef.”
Sydney Pereira is an intern with ThinkProgress.