Despite the temperature of 35 C, a fishery administration vessel set off at 8:30 am from the northern shore of China's largest freshwater lake, Poyang Lake, sailing along the waterway in search of endangered finless porpoises.

The Yangtze finless porpoise is the only freshwater subspecies in the finless porpoise family. The IUCN-listed critically endangered species, only found in parts of the middle and lower reaches of the Yangtze River, has nearly half of its population living in Poyang Lake.

In January 2020, a 10-year fishing ban went into effect in pivotal waters of the river, which has improved the living conditions of the porpoises as their newborns continue to trickle in.

"As Poyang Lake enters the dry season, finless porpoises are spotted more often," says 50-year-old Zhan Baishan, head of the local finless porpoise rescue team in Duchang county, East China's Jiangxi province.

"We've been neighbors with finless porpoises since we were kids. They live underwater and we live on the surface," adds Zhan, whose family has lived on a boat for generations.

He is, however, still concerned for the species. "Recently, the water level of Poyang Lake dropped sharply. We have to patrol the lake every day to prevent the porpoises from entering the main waterway and injuring themselves."

Of late, drought conditions triggered by sustained hot weather and low precipitation in Jiangxi have reduced the lake by 75 percent, according to local authorities. The lake officially entered this year's dry season on August 6, the earliest date since records started in 1951 and 69 days earlier than the average starting date between 2003 and last year.

In recent years, an aquatic life protection and rescue center has been established in Jiangxi, attracting more than 2,000 volunteers to set up 203 patrol teams. This has formed a relatively comprehensive patrol and rescue network for finless porpoises, playing a major role in safeguarding them despite the rare drought.

When the boat that set off from the northern shore reached Songmenshan around 9 am, porpoises jumped out of the water. "There's a mother and her baby," Zhan shouted excitedly. As the patrol team sailed along the way, they spotted at least 10 porpoises.

He says it is common to see the rare porpoises in the lake these days, which indicates the growing population of the species.

When the boat approached the shallow water, Yu Shunyuan, a member of the county's fishery administration team, took a bamboo pole and stuck it to the bottom of the lake to assess the water depth in case the porpoises run aground.

"We patrol on foot where the boat cannot reach. If there are shrimp pots left by the lake or garbage discarded by passing boats, we clean them up to avoid scratching the finless porpoises," Yu says.

After the boat reached the shore, Yu, Zhan and the rest of the crew jumped onto the grassy land and began their daily patrol of about half an hour. After a lunch break, they continued their ride in the other direction.

According to the weather forecast, high temperatures and little rain will continue in Jiangxi in the coming week, and the water level in Poyang Lake will continue to decline.

Meanwhile, patrol and rescue volunteers are intensifying their efforts to safeguard the finless porpoises, migrating birds and other species.