Wetland · Shanghai
Chongming Dongtan Wetland
崇明东滩
Where the Yangtze meets the sea: Shanghai's migratory-bird frontier
Chongming Dongtan is the growing tidal wetland at the eastern tip of Chongming Island, where the Yangtze enters the East China Sea within the municipality of Shanghai. A national nature reserve and Ramsar site, it is one of the main shorebird stopovers of the Yangtze estuary and in 2024 became Shanghai's first World Heritage site as part of the Yellow Sea–Bohai Gulf migratory bird sanctuaries.
- UNESCO World Heritage (natural) — Migratory Bird Sanctuaries along the Coast of Yellow Sea-Bohai Gulf of China, Phase II · 2024
- Ramsar site · 2002
- National nature reserve · 2005
Key facts
Overview
Chongming is an alluvial island built entirely from Yangtze silt, and Dongtan — “the eastern flats” — is its youngest part, still extending seaward each year. Beyond the sea wall lie reed marsh, sedge and bulrush meadows and wide bare mudflats that flood and drain with every tide.
The site matters because of its position. The Yangtze estuary sits on the East Asian–Australasian Flyway, and Dongtan is the first large feeding ground many shorebirds reach after crossing the sea from the south, or the last before the flight on. Ducks, geese, cranes and herons winter here, and the reserve has recorded around 300 bird species. In 2024 it was added, with four other coastal sites, to the World Heritage listing first inscribed for the Yancheng coast in 2019.
How the landscape formed
The Yangtze carries a large sediment load to its mouth, where river water meets the tides and the mud settles. Chongming Island first appeared as sandbanks in the seventh century and has grown by accretion ever since; Dongtan is the leading edge of that growth, with its outer flats advancing into the estuary. Reduced sediment supply since the building of the Three Gorges and other upstream dams has slowed that advance, and managers now watch the balance between accretion and erosion closely.
Highlights
Dongtan Wetland Park
东滩湿地公园
The visitor area next to the reserve, with boardwalks through reed beds and pools.
Intertidal flats
潮间带
The broad mudflats beyond the vegetation line where shorebirds feed at low tide.
Bulrush meadows
海三棱藨草
Native sedge marsh whose tubers feed wintering geese and cranes.
Plants and wildlife
The main management challenge has been smooth cordgrass (Spartina alterniflora), introduced to China in the late 1970s to stabilise mudflats, which spread across Dongtan and displaced the native sedge and bulrush on which birds feed. A large-scale ecological restoration project since the 2010s has cleared cordgrass from much of the reserve, rebuilt water levels and replanted native vegetation.
Plants
Reeds
芦苇
Dense reed beds along the upper marsh shelter reed parrotbills and warblers.
Bulrushes
藨草
Native sedges of the lower marsh, the key winter food for waterfowl.
Wildlife
Hooded crane
白头鹤
A small population of this vulnerable crane winters on the Dongtan marshes.
Tundra swan
小天鹅
Winters on the pools and flats of the reserve.
Chinese sturgeon
中华鲟
The estuary waters are a nursery for young fish of this critically endangered species.
History
7th century
Chongming sandbanks appear
The island begins to form from Yangtze silt at the river mouth.
1998
Nature reserve founded
Shanghai sets aside the eastern flats for migratory birds.
2002
Ramsar listing
Recognised as a wetland of international importance.
2005
National nature reserve
Raised to the status of Chongming Dongtan Bird National Nature Reserve.
2024
UNESCO World Heritage
Added in Phase II of the Yellow Sea–Bohai Gulf migratory bird sanctuaries, Shanghai's first World Heritage site.
Through the seasons
Spring
Shorebird migration peaks in April and May, with godwits, curlews and sandpipers on the flats.
Summer
Hot and humid, with breeding reed birds; typhoon season brings occasional closures.
Autumn
Southbound shorebirds from August to October; the reeds turn gold.
Winter
Ducks, geese, swans and hooded cranes; cold wind off the sea makes warm clothing essential.
Routes and ways in
Wetland park boardwalks
Marked boardwalks and hides in the public visitor zone next to the reserve.
Sea-wall birding
Birders scan the flats from the sea wall at rising tide, when birds move closer.
Practical notes
- The core reserve is closed to the public; visits are to the adjacent wetland park and designated areas.
- Chongming Island is linked to the Shanghai mainland by the Yangtze River tunnel-bridge and to Jiangsu by road bridges.
- Bring binoculars or a telescope; birds on the flats are often far out.
Frequently asked questions
Sources
- Migratory Bird Sanctuaries along the Coast of Yellow Sea-Bohai Gulf of China — UNESCO World Heritage Centre (retrieved 27 September 2026)
- Shanghai Chongming Dongtan added to World Heritage List — Shanghai Municipal People's Government (retrieved 27 September 2026)
- Ramsar Sites Information Service — Ramsar Convention Secretariat (retrieved 27 September 2026)