Since the beginning of the 1960s, scientists have known about a so-called “dead zone” in the Gulf of Oman, an area of water almost completely devoid of oxygen. A recent study has shown that this area, already the size of Florida, is continually getting larger.
Dead zones are vast expanses of water which contain very little or no oxygen, which suffocate marine fauna. As a result, any organisms which require oxygen to breathe flee the area and non-moving species such as crustaceans die, while methanogenic bacteria develop. We now know why these areas are multiplying and getting larger. A study published a few months ago suggested that these zones had quadrupled since the 1950s, and are nowadays extending over millions of square kilometers. One such area in the Gulf of Oman was recently the object of analysis: it could be even bigger than was previously thought!
According to the scientists, the dead zone in the Gulf of Oman, the largest in the world, had been underestimated until now, notably due to a lack of samples. Piracy and conflict in the area had prevented new data from being gathered. “Our research shows that the situation is worse than we have feared and that the dead zone is large and continuing to expand. The ocean is suffocating”, says Bastien Queste, a researcher from the British University of East Anglia. According to the study, published on Friday 27th April 2018 in Geophysical Research Letters, the “dead zone” could now be larger than Scotland.
The researchers had sent submarine robots to the area for a period of eight months. The robots were able to dive a thousand meters down to evaluate the damage, and what they found was not good news for the aquatic life in the area, or possibly for our atmosphere in general.
Remember also that the phenomena leading to periods of mass extinction throughout history were often linked to hot climates and oceans lacking in oxygen. And as global warming continues, there is a strong bet that the oceans will continue to lose oxygen at high speed. The main problem nowadays is global warming: hot water holds less oxygen, and surface water temperatures are rising. As a result, it becomes more difficult for oxygen to descend to the ocean’s depths.