The Gulf of Oman is the site of the world’s largest marine ‘dead zone’, an area almost devoid of oxygen and roughly the size of Florida, data gathered by robots reveals. The area is larger than scientists previously thought and is expanding.Marine life needs ample oxygen to survive. And while oxygen minimum zones (OMZ) are not uncommon and naturally occur as a result of imbalance between atmospheric oxygen supply and decay of organic matter, the dearth of oxygen in the Gulf of Oman’s OMZ has been revealed to be ‘the most dramatic’ so far, according to a paper in Geophysical Research Letters1. “This area of 80,000 square kilometers is now anoxic [or depleted of oxygen], extending the Arabian Sea’s oxygen minimum zone into its extremities where people live and fish,” explains Bastien Queste from UEA’s School of Environmental Sciences and member of the research team, which included scientists from the University of East Anglia and Sultan Qaboos University. Tuna fishing, which is a huge industry off the Omani coast, is expected to be badly affected. The existence of a large dead zone in the Arabian Sea was first documented in the 1960s, but many decades of geopolitical tensions and piracy have hindered attempts at collecting data. (…)