Torrential rainfall that has pounded southern China for almost two months has reportedly caused more than 50 million flood victims and is even sparking ecological concerns for South Korea's Jeju Island.

Chinese media cited government data on Wednesday that 54-point-eight million people had become victims of flooding in the southern Chinese provinces of Jianxi, Anhui and Hubei.

Of these, 158 have died or gone missing, while three-point-76 million have been evacuated.

Around 41-thousand homes have collapsed and some 52-thousand square kilometers of farmland have been inundated, resulting in damage estimated at around 23 billion US dollars.

As the Three Gorges Dam continues to spew huge amounts of flood water, concerns are rising that the massive amount of fresh water flowing into the South China Sea could have a negative ecological impact on the coastal waters off Jeju Island.

On average, 44-thousand tons of fresh water flows into the ocean from the Yangtze River each second. But that amount has increased to 77-thousand tons per second due to the heavy rainfall. 

As a result, a tremendous amount of water from the Yangtze could flow into the coast of Jeju Island about a month from now. Ecologists say that could cause the salinity of ocean water off Jeju to decline, resulting in higher sea water temperatures and wreaking havoc on the marine life in the region.

The Jeju Marine and Fisheries Research Institute set up remote-controlled detection centers on the western waters off the coast of the resort island earlier this month and has stepped up monitoring of salinity levels.