GUIYANG, Nov. 20 (Xinhua) -- Yang Liemeng, 50, misses his childhood, when he could swim in the local Wuma River. "When the sun went down, you could see fish leaping out of the water."

However, the river, running through the city of Renhuai, southwest China's Guizhou Province, has been covered with white foam caused by pollution in recent years. Meanwhile, due to overfishing, "fish leaping" is a rare sight for the younger generation.

Water pollution has raised concerns of the local government. In 2009, the government shut down the local paper mills, which had been causing pollution to the river.

To improve water quality, pollution sources have to be dealt with first, said Feng Jinwei, an official with the local government.

Apart from the government, local people also wanted to make efforts.

Yang said that when he and some of his friends were walking along the river one day last year, they realized "something should be done" to bring back their childhood memories of the river.

In May 2017, they founded a volunteer group to stop illegal fishing and report pollution sources to the authorities. Yang and his friends devoted dozens of hours per week to patrol the river bank, stopping people from illegal fishing and waste dumping.

But the work wasn't easy. In the second month of patrolling, Yang was involved in a physical conflict and had his ear injured when trying to stop people catching fish. He stayed in hospital for 16 days.

"When the man who hit me came to visit, I tried to persuade him to join us," Yang said. "But the man declined."

He did, however, tell Yang he would no longer fish in the river.

"Even after getting injured, I never regretted doing this," Yang said.

Yang's story spread throughout his town, making the volunteer organization well-known. More than 400 people have since joined the organization, according to Guo Xiaoyong, vice head of the group, most of whom are local farmers and merchants.

"As the patrolling team becomes known by more people, it becomes easier for them to prevent pollution and illegal fishing in the river," Guo said. "Since the founding of the group, more than 1,000 people have been stopped by the volunteers for causing damage to the river."

"It makes me feel satisfied to protect the river," Yang said. "I'll keep doing this until the day I'm too old."