Wetland restoration

The area, in northeastern Dongying at the Yellow River estuary, was once seen as inhospitable for birds and other wildlife because water was scarce during the dry season and overwhelming during the wet season, flooding the land, said Hu, a Dongying native.

Recognizing its ecological, geographical and societal significance, the city established a nature reserve in 1990, which has since grown to 153,000 hectares. The reserve received national-level status and became known as the Shandong Yellow River Delta National Nature Reserve two years later.

Toward the end of the decade, the oriental stork began appearing there.

"The oriental stork is particularly sensitive about its living environment and is considered an indicator of how healthy wetlands are," said Zhao Yajie, deputy director of the ecological monitoring center in the nature reserve. "In fact, it had never been seen in the nature reserve before the late 1990s."

The migratory birds mainly inhabit marshes, wetlands and pond shores. They are found during the summer in the provinces of Heilongjiang and Jilin in Northeast China and the Inner Mongolia autonomous region, and during the winter in Anhui, Hubei, Hunan, Jiangsu and Jiangxi provinces. They are also present in Japan, the Korean Peninsula and Russia.

"In the autumn of 1997, the reserve's first oriental stork was observed pausing here on its journey southward, using the location as a temporary stopover," Zhao said. "In 2003, a group of the storks nested here for the first time, coinciding with the wetland conservation project in the nature reserve that was occurring at the time and underscoring the project's success."

The first successful hatching of the species occurred in 2005, she added.

In 2002, a wetland restoration project was launched in the nature reserve. It involved building dams to prevent seawater from intruding and injecting water from the Yellow River during its peak flow period into the reserve to retain freshwater and reduce salinity. This was an effective way to create a freshwater wetland environment and provide a suitable habitat and food resources for oriental storks, she said.

Rainfall is scarce in the Yellow River Delta in Dongying — only about 590 millimeters a year — and with as much as 1,550 mm of water being evaporated from the wetlands annually, more of it is essential. The reserve has thus adopted replenishment measures, including diverting water from the Yellow River during its peak flow period in June, she said.

Following years of wetland restoration efforts, there are now more than 20,000 hectares of freshwater wetlands in the reserve. The expansion has led to the oriental stork establishing itself as a regular resident of Dongying, where it lives from February to November, she said.