In the waters of the Arabian Sea, an oxygen-free “dead zone” the size of Scotland is spreading and raises the concern of scientists, who believe that it could be related to climate change.
In Abu Dhabi, Zouhair Lachkar works in his laboratory on a computer model of the Gulf of Oman, an area of the Arabian Sea bordering the sultanate of the same name and Iran. Moving colored images show changes in temperature, sea level and, most importantly, oxygen levels.
These models and new research unveiled this year show a disturbing trend.
The dead zone of the Arabian Sea is the largest in the world, says Lachkar, senior researcher at NYU Abu Dhabi University.
“It starts about 100 meters (deep) and goes down to 1,500 meters, so that almost the entire water column is completely devoid of oxygen,” he says.
Lachkar and other researchers believe that global warming is driving the area’s expansion, raising concerns for local ecosystems and industries, such as fishing or tourism.
“Dead zones” are natural phenomena, but this one, whose boundaries extend from the Strait of Hormuz to the Gulf of Aden and east to the Indian coast, seems to have grown since last statement from the 1990s.
This result was achieved through the use of deployed diving robots where researchers can not go. The operation was conducted by the British University of East Anglia in collaboration with Sultan Qaboos University of Oman.
Measurements of oxygen levels in 1996 showed very low concentrations. But the latest study in 2015 and 2016 found that levels had dropped again.
And unlike the 1990s, when the lowest levels were confined to the heart of the “dead zone”, halfway between Yemen and India, they now extend well beyond.
At NYU Abu Dhabi, Mr Lachkar explains that the “dead zone” of the Arabian Sea seems to be caught in a cycle where the warming of the sea reduces oxygen, which in turn reinforces warming. This “can be very scary for the climate,” he says.
From Bombay, in western India, to Muscat, on the shores of the Gulf of Oman, several ports overlook the Arabian Sea. These coastal areas and their populations will be affected by the expansion of the “dead zone”. Fish, important livelihoods for people living in the area, might suffer from the reduced habitat.
“When the oxygen concentration falls below certain levels, the fish can not survive,” says Lachkar.
To carry out his research, this researcher relies on a vast and powerful computer center that cost several million dollars.
In 2016, the United Arab Emirates renamed its Ministry of Environment and Water to the Ministry of Climate Change and Environment, demonstrating their commitment to addressing the challenges in this area.
“This is an important issue, not only for scientific but also economic reasons,” says Lachkar. “Fishing is an important source of income and is directly affected” by this phenomenon.
Coral reefs and, by extension, tourism could also be affected, he said.
Right next to her lab is another research center where scientists like Diana Francis are studying the impact of climate change on a global scale.
In 2015, the Paris climate agreement saw the world commit to reducing CO2 emissions in order to mitigate global warming. But US President Donald Trump withdrew his country last year.