Yancheng

Over twenty million migratory birds stake their lives on Yancheng every year, and there is no backup. The 582 kilometres of Yellow Sea coastline running through this Jiangsu Province prefecture form the most critical feeding stop on the East Asian-Australasian Flyway — the transcontinental migration route connecting Siberian breeding grounds to Australian wintering sites. If Yancheng's mudflats degrade, there is no alternative refuelling point of comparable scale. This is what zero redundancy looks like at continental scope.

The name Yancheng means "City of Salt," and since at least 119 BC — when the Western Han government established Yandu County — the economy ran on salt extraction from these same coastal flats. From the 8th century, the city anchored a canal network connecting salt pans to the Grand Canal, and government depots administered the salt monopoly that funded dynastic treasuries. The shift came fast. In 1983, the Yancheng National Nature Reserve was established on mudflats that had previously been salt pans. In 2019, Yancheng's coastal wetlands became China's first coastal natural World Heritage site.

Yancheng flipped from two millennia of extracting its coastline to protecting it in under a generation — an alternative stable state where the same geographic feature (tidal mudflats) sustains a completely different economic logic, locked in by UNESCO designation and tourism revenue that now exceeds what salt ever generated.

The wetlands cover 453,000 hectares — the largest coastal nature reserve in China — and host hundreds of wild red-crowned cranes each winter, a significant share of the species' mainland migratory population. Over 8,500 Père David's deer roam the Dafeng reserve, the vast majority of a species that went extinct in the wild during the Boxer Rebellion. Like salmon spawning rivers — irreplaceable waypoints on a long migration route where the destruction of one node cascades across the entire network — Yancheng's tidal flats are a keystone habitat.

The city is home to 6.7 million people across 16,931 square kilometres of Jiangsu's largest prefecture, averaging roughly three metres above sea level with no significant elevation anywhere. The flatness that once made it ideal for salt pans now makes it ideal for the mudflat ecosystems that migratory birds require.