Scientists raise the alarm, pointing the finger at global warming. At present, the dead zone is the size of Scotland. For scientists, this is a worrying trend. Lack of oxygen makes fish survival difficult. The problem also affects coral reefs and tourism.
Abu Dhabi (AsiaNews/Agencies) – In the waters of the Arabian Sea, a vast "dead zone" the size of Scotland is expanding and scientists say climate change may be to blame.
In his lab in Abu Dhabi, Zouhair Lachkar is labouring over a colourful computer model of the Gulf of Oman, showing changing temperatures, sea levels and oxygen concentrations.
His models and new research unveiled earlier this year show a worrying trend.
Dead zones are areas of the sea where the lack of oxygen makes it difficult for fish to survive and the one in the Arabian Sea is "is the most intense in the world," says Lachkar, a senior scientist at NYU Abu Dhabi in the capital of the United Arab Emirates.
"It starts at about 100 metres and goes down to 1,500 metres, so almost the whole water column is completely depleted of oxygen," he told AFP.
Dead zones are naturally occurring phenomena around the world, but this one appears to have mushroomed since it was last surveyed in the 1990s.
Lachkar and other researchers are worried that global warming is causing the zone to expand, raising concerns for local ecosystems and industries including fishing and tourism.
These coastal hubs and the populations beyond them, from Mumbai in India to Muscat (Oman) will be affected by further expansion of the dead zone.
Fish, a key source of sustenance in the region, may find their habitats compressed from deep underwater to just beneath the surface, putting them at risk of overfishing and extreme competition.
"When oxygen concentration drops below certain levels, fish cannot survive and you have massive death," Lachkar said.
"Fishing is an important source of revenue and it's directly impacted by the oxygen," he added. Even coral reefs and, by extension, tourism could be affected.