There are five freshwater estuaries that drain into Sanniang Bay, including the Jinwo, Dafeng and Nanliu rivers. As the fresh water mixes with the seawater, unique conditions are created that allow an abundance of marine species to survive, not least among them the Chinese white dolphin.

This means there is ample food to sustain the dolphins' population, according to dolphin expert Zhao Yi.

"Especially at the mouth of the Dafeng River, dense mangrove forests grow, acting as a natural filter. The river water passing through the mangroves undergoes ecological filtration, purifying pollution from upstream human activities and adding more nutrients. This significantly contributes to the improvement of water quality in Sanniang Bay," said Zhao, who, along with his wife Pan Yue, moved to a village near Sanniang Bay in Qinzhou, Guangxi Zhuang autonomous region, almost 20 years ago to observe and protect Chinese white dolphins.

Though their work is tireless, Zhao and Pan said there has not been enough international research into Chinese white dolphins, so understanding them has relied on years of observation to gather data for further protection and study.

Based on their observations, Chinese white dolphins prefer living in shallow waters no more than 12 meters deep, a condition that Sanniang Bay meets perfectly. "More importantly, amid human activities and industrial development, Sanniang Bay has received sufficient protection and has not been polluted," Pan said.