Algae blooms in the Gulf of Oman. Image: Associated Press
If you follow environmental news, you’ve probably heard about dead zones. In particular, you’ve probably heard about the one in the Gulf of Mexico. There’s another one, though—and it’s massive. Sitting in the Gulf of Oman is a dead zone that’s bigger than Scotland.
Dead zones aren’t exactly rare. They generally happen in various places each year. In short, fertilizer-laden runoff from the massive agricultural industry leaches into rivers which eventually make their way to the sea. Since fertilizer is, well, fertilizer, that runoff causes massive algal blooms. Although those blooms occur naturally, when they’re ‘roided up with nitrogen and phosphorus things get a little out of hand. Then, populations of the phytoplankton that feeds on it explodes. When those all die off and sink to the bottom, their decomposing bodies end up sucking all the oxygen out of the water. And there you have a dead zone, which is not good for anyone.
Dead zones around the world. Image: Robert Simmon & Jesse Allen / NA
Although the dead zone in the Gulf of Oman has been known about for about 50 years, it’s been a little difficult to study. Pirates don’t exactly care about science, after all. But now that robots are readily available, researchers have been able to put together a study of the area—and they found that it’s much worse than they thought. “Our research shows that the situation is actually worse than feared,” said Dr. Bastien Queste of the University of East Anglia, “and that the area of dead zone [in the Gulf of Oman] is vast and growing.”
The study took place over the course of eight months, in which two robots sampled oxygen concentrations at different depths.
In their report, which was published in Geophysical Research Letters, scientists stated that they found an area just over 80,000 square kilometers that is almost completely devoid of oxygen. Not only does that make it nearly impossible for anything to live in the area, but it has another devastating effect. “When oxygen is absent, the chemical cycling of nitrogen – a key nutrient for plant growth – changes dramatically,” Queste explained. “Nitrous oxide, a greenhouse gas 300 times more potent than CO2 is produced.”
It’s not just Oman that is affected, either. Iran and Pakistan are just to the north, and it is an important body of water to the United Arab Emirates. As the oceans warm, water ventilation from the cooler deep ocean and the warmer surface becomes more and more limited, which in turn leads to poor mixing of various gases that make the ocean so important to all life.
“The region is now anoxic,” Dr. Queste poignantly summed up. “The ocean is suffocating.”
