In this undated photo, a Yangtze finless porpoise frolics in the river in Yichang, Hubei province, in April 2018. (LIU SHUSONG / FOR CHINA DAILY)

NANCHANG－After working on a fishing boat for decades on Poyang Lake, China's largest freshwater lake connected to the Yangtze River, Wang Diyou has given up his fishing career.

Like the 52-year-old former fisherman, residents in Gutang town in the city of Jiujiang, Jiangxi province, made a living fishing on the lake for generations.

However, dwindling aquatic resources and degrading biodiversity caused by long-term overfishing worried anglers who genuinely love their hometown.

"Electric fishing may affect the breeding ability of the fish and accidentally injure the finless porpoise," Wang said. "For the sake of future generations, we must do something to protect them."

Wang Diyou, a 52-year-old former fisherman, set up a patrol team to protect the endangered Yangtze finless porpoises in Jiujiang

According to scientific research by the then Ministry of Agriculture, there were around 1,000 wild finless porpoises in China in 2017, primarily in the main stream of the Yangtze and in Poyang.

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In 2016, Wang became a patroller on the lake. His job was to observe the finless porpoises and migratory birds, clean up garbage in the water and report illegal fishing and sand mining.

Two years later, Wang set up a patrol team to protect the endangered Yangtze finless porpoises in Jiujiang. Some team members had even been reported by him before for illegal fishing.

"From some initial misunderstandings about my work to fighting side by side with me, they gradually realized that it's our duty as fishermen to guard the lake," Wang said.

To further preserve the biodiversity of the Yangtze River, China began a 10-year fishing moratorium from the beginning of this year in 332 conservation areas in the Yangtze River Basin.

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Due to the ban, more than 100,000 fishermen from over 300 fishing villages situated around Poyang had to end their traditional roles and embrace new identities ashore. Many fishermen in Gutang chose to look for jobs in nearby industrial parks.

Among Wang's team members, some had worked as security guards in the industrial parks after going ashore, while others had started raising crayfish. But all of them eventually decided to return to Poyang and work full time for environmental protection.

"These years, the number of fish in the lake has obviously increased," said Wang Ruanhua, a local villager who joined the team this year. "While patrolling, we often see the finless porpoises leaping out of the water. The scene is spectacular."

Although his monthly salary of 3,000 yuan (US$425) is lower than what he used to earn by fishing, he said the work gave him a sense of pride.

So far, the team consists of six former fishermen with an average age of over 50 years.

Thanks to the collective efforts of the former fishermen and the local government, illegal fishing in the lake is now a rare sight. Increasingly, local fishermen are joining the fight to strengthen the protection of aquatic life.

"For the sustainable development of Poyang Lake, we old guys will stick to our posts," Wang Diyou said.