After hearing that an area in Jiangsu province had been listed as a UNESCO World Heritage Site in July, 57-year-old Li Dongming couldn't sleep until the small hours.

The freelance photographer was excited to hear that the Migratory Bird Sanctuaries along the Coast of Yellow Sea-Bohai Gulf (Phase I) had been awarded the honor.

The area was listed as a World Heriatge Site in Baku, capital of Azerbaijan.

"As a bird photographer and conservationist, I feel that 2019 was my best year to date because of this decision," he said.

Li, who lives in Dafeng district, Yancheng, Jiangsu, began taking pictures of birds 10 years ago. Two years later, he said he saw his first spoon-billed sandpiper, a shorebird known for its flattened bill that flares into the shape of a spoon at the tip. Knowing that the species was critically endangered, he started to focus on it exclusively.

At first, he drove 160 kilometers to Xiao Yangkou in Rudong, Jiangsu, to see the birds.

This small port north of the Yangtze River estuary on the southernmost reach of the Yellow Sea was known for its rich intertidal mudflats stretching for some 250 kms.

During a five-day survey in October 2013, water bird experts recorded at least 140 spoon-billed sandpipers along 120 km of coastline near Rudong.

However, Li said the mudflats at the site virtually disappeared during the next two years. "Pollution from chemical plants, along with land reclamation and the spread of spartina (also known as cord grass) are some of the reasons," he said.

At Tiaozini in Dongtai, Yancheng, researchers and bird watchers found spoon-billed sandpipers.

During the migration season from March to November, Li drives 100 km from his home to see these birds.

"I go almost every day during the season to count and take pictures of them," he said. He once saw more than 20 spoon-billed sandpipers on one patch of the mudflats. The highest count by experts is nearly 200.

To get good photographs of the birds, he often has to walk 4 or 5 km across the mudflats.

Over the years at Tiaozini, he has photographed more than 200 types of bird, including about 50 species of shorebird. He has also joined several nonprofit grassroots conservation organizations, such as the Tiaozini Loving Bird Society, to advocate protecting the area and the birds there.

"Along the provincial highway, only an 85-km stretch of coastline, mainly in Dongtai, is free of chemical plants," Li said. "There are such plants in the north and south, so the shorebirds now mainly gather at Tiaozini. The loss of habitat has been rapid, and the future for these birds is gloomy."

That was why he was so excited that Tiaozini had been included as part of the World Heritage Site.

"I saw this as a ray of light in the gloom," he said.