The Yangtze River water turns red

A section of the Yangtze River suddenly turned red like tomato juice and authorities did not find the cause.

People in Chongqing, the southwestern city of China, discovered a change in the water color of the Yangtze River on September 6. The same phenomenon also appeared in many other places on the river, ABC reported.

Officials have not figured out why the river has changed color, but environmental officials suspect industrial and silt waste from upstream floods is the culprit.

Emily Stanley, an expert on continental water sources at the University of Wisconsin in the US, thinks algae are not the cause.

The scene of the Yangtze River in Chongqing City, China on September 6.

'When the water turns red, many people think of the red tide. But the type of algae that causes red tide only exists in seawater, not fresh water. So the red tide is not related to the strange phenomenon on the Yangtze River , 'Stanley said.

Water in rivers, lakes and streams often turns red by some biological causes. According to Stanley, in most cases, the water is tinged with red due to the activity of anaerobic bacteria capable of coloring. Anaerobic bacteria appear in the water when oxygen levels drop below normal levels. Because the rivers flow continuously, the river water constantly mixes the air above. So oxygen levels in river water are always normal and anaerobic bacteria cannot survive in such an environment.

After seeing some pictures of the Yangtze River in Chongqing, Stanley said that this is a phenomenon caused by human activities.

'It seems to be a consequence of pollution. In the past, rivers and lakes turned red very quickly because humans poured dye into the water , 'Stanley explained.

The Tien River water in Sichuan Province, China used to turn red in December last year because people poured red dye into the river. Chinese police found the dye was discharged from a chemical factory.