The continuous dumping of crushed rock from bulk tankers along the Great Barrier Reef maritime route may counteract the acidification of seawater caused by fossil fuel burning. But it comes with unknown side effects on the marine environment and coral reefs. According to a study from the Australian Science Agency
in what is described as The “first-order assessment” scientists at CSIRO found that, in theory, It is possible to go back in time about the effects of decades of fossil fuel burning. But that drastic step comes with it. “Unexpected risk”;
In addition to warming the atmosphere and oceans, rising atmospheric CO2 levels from burning fossil fuels have altered ocean pH, making it harder for corals to build skeletons. This is a process known as calcification.
Dr Mathieu Mongin, lead scientist on the study, said researchers are now forced to consider the possibility of radical interventions to save coral reefs due to a lack of global action on the climate crisis.
Professor Terry Hughes, a reef expert Explain the concept of adding material to the waters of the Great Barrier Reef. As simulated in the research study,
Reef scientists are exploring the possibility of local interventions to try and buy time for the world’s largest reef system.
Experiments have already been conducted from the delivery system to spray trillions of nanoscale sea salt crystals to lighten the clouds. This can be used to cool reefs during the summer when corals are at risk of bleaching.
The new study, published Tuesday in the journal Environmental Research Letters has raised the idea of using existing transport routes to deploy alkaline materials that can increase the pH level of water, making it less acidic.
The research used actual pH measurements from sensors aboard the Rio Tinto mining company’s ship, which traveled the Weipa to Gladstone Trail, a journey that would normally last four days.
Mongin and colleagues used these measurements to test and calibrate their computer model that simulated two years of material released using oceans and weather between January 2014 and December 2015.
Mongin, a carbon chemist and modeler at CSIRO, said: “Because no action has been taken on climate change and emissions reductions, there has been no progress on climate change and emissions reductions.” This leads us to explore these interventions.
“We must explore all warnings and must do so with our scientific colleagues and reef managers.”
This study looked at the potential effects of adding crushed olivine solution. This is a common mineral at a rate of 90,000 tons in three days ocean currents disperse the solution along the coral reefs.
Mongin said the model shows that the material must be continuously added to seawater to maintain elevated pH levels.
“The day you stopped within three months You will go back to where you were,” he said.
This model proposes to release material continuously every time. Three days for a year along the length of the reef That would offset the four years of ocean acidification caused by current CO2 emissions.
“We are not advocating for this intervention,” Mongin said. “We are dealing with the current state of the Great Barrier Reef. We see this coming. And we don’t see any action. And it’s hard for us to think about these interventions.
“But my job is to test to keep the public informed of what might happen if we don’t take action now. We are stepping out of our comfort zone. But we have to.”
Scientists conducted a small experiment on coral shoals south of the Great Barrier Reef, showing that adding an alkaline solution to the water increases the rate of coral skeleton formation.
Prof. Hughes, from the James Cook University Center of Excellence for Coral Education, said the idea of adding 90,000 tons of olivine “every three days for a century or so” was “negligent”.
He said: “The study did not examine the ecological effects of handling chemicals in large quantities of water. It’s too much to admit that the light level will drop.
“The Australian government has spent hundreds of millions of dollars in recent years to reduce water pollution on coastal reefs. Deliberately lowering light levels across the GBR would have a significant negative effect on corals, seagrass and other important species. using sunlight for photosynthesis.
Dr. Kennedy Wolf, marine biologist at the University of Queensland. A contributor to previous ocean acidification trials said it was important to understand the potential potential of broader conservation measures.
But he said studies show that The “major shortcoming” of this approach is the need to continually add material to the ocean.
He said: “A study shows Seawater chemistry quickly returns to pre-intervention levels if alkaline injection is stopped. Does this mean that 90,000 tons of alkalinity sources have to be added to the GBR every three days forever?
“Actually, we probably need to add more and more alkalinity to the system. To counter the ongoing escalation of ocean acidification caused by global emissions unless emissions are strictly controlled in parallel with alkalinity injections.”
The average global ocean pH is at its lowest level in 800,000 years.
Although the water’s pH level fluctuates naturally every day. and throughout the season One study found that the highest levels of CO2 exposed by coral in the Great Barrier Reef in the 1960s are now the lowest.
Dr Katharina Fabricius, Senior Research Scientist at the Australian Institute of Marine Science, said: “Overall, it is clear that calcification in coral reefs has decreased.
“GBR has grown 6% acidity over the last 10 years. We are following the trend. [of CO2 levels] in the atmosphere”
She said that while some marine creatures may be able to move to escape from warming temperatures, they are still in danger. “For ocean acidification There is no escape.”