Wetland · Hainan
Dongzhaigang Mangroves
东寨港红树林
China's first mangrove reserve, in a bay created by an earthquake
Dongzhaigang is a shallow, funnel-shaped bay on the north-east coast of Hainan, east of Haikou, lined with the most extensive and species-rich mangrove forests in China. Its nature reserve, founded in 1980, was the first in China dedicated to mangroves, became a national nature reserve in 1986 and was among the first Chinese wetlands listed under the Ramsar Convention in 1992.
- National nature reserve · 1986
- Ramsar site · 1992
Key facts
- National nature reserve
- 1986
- Ramsar site
- 1992[1]
- Origin of the bay
- Subsidence in the 1605 earthquake
- Location
- Meilan district, Haikou, Hainan
Overview
The bay is a sheltered tidal lagoon whose muddy shores and creeks are fringed by dense mangrove forest. At high tide the sea floods among the trees; at low tide it exposes mudflats that feed crabs, mudskippers, fish and wading birds. Villages around the bay fish, farm oysters and gather shellfish in the channels.
The bay itself is young. It took its present form after a great earthquake struck northern Hainan in 1605, when land subsided and the sea flooded dozens of villages. Remains of the drowned settlements — tombs, wells and stone foundations — are still reported on the bay floor, and local people speak of the “villages under the sea”.
How the landscape formed
Dongzhaigang lies on a fault zone in northern Hainan. The 1605 Qiongshan earthquake, estimated at around magnitude 7.5, caused a section of the coast to subside by several metres, turning low farmland and villages into a shallow bay open to the sea. Since then rivers and tides have spread fine mud across its floor, and mangroves have colonised the sheltered intertidal zone, their roots trapping sediment and slowly building up the shore.
Highlights
Mangrove forest
红树林
Dense stands of salt-tolerant trees along the creeks and shores, seen from boardwalks or by boat at high tide.
Villages under the sea
海底村庄
The sites of villages drowned in the 1605 earthquake, occasionally visible at very low tides.
Yanfeng
演丰镇
The town on the bay that is the base for visits to the reserve.
Mudflats
滩涂
The intertidal flats exposed at low tide, busy with crabs, mudskippers and feeding birds.
Plants and wildlife
Hainan has the greatest diversity of mangrove species in China, and Dongzhaigang holds most of them. The forests protect the coast from storm surges and typhoon waves, filter water and serve as nurseries for fish and shellfish. In winter the bay attracts migratory waterbirds, including the endangered black-faced spoonbill.
Plants
Bruguiera
木榄
Bruguiera gymnorhiza, a tall mangrove with knee-shaped breathing roots.
Kandelia
秋茄
Kandelia obovata, whose long seedlings germinate while still on the tree.
Grey mangrove
白骨壤
Avicennia marina, a pioneer on the seaward edge with pencil-like roots rising from the mud.
Sonneratia
海桑
Mangrove apple, tall trees of the lower estuary with cone-shaped roots.
Wildlife
Black-faced spoonbill
黑脸琵鹭
An endangered wader of East Asia that winters in small numbers on the bay.
Mudskipper
弹涂鱼
Fish that skip and climb across the mud at low tide.
Fiddler crab
招潮蟹
Crabs that wave one enlarged claw on the mudflats, a common sight at low tide.
Culture and legend
The communities around the bay have long lived from the mangroves and the tides, gathering shellfish, crabs and fish, and the drowned villages of 1605 remain part of local memory. The Qiongshan earthquake is one of the most destructive recorded in southern China, and its effect on the landscape is still visible in the bay's outline.
Qiongshan earthquake
琼山大地震
The earthquake of 1605 that caused the land around the bay to sink beneath the sea.
History
1605
Qiongshan earthquake
Land subsides and the sea floods villages, creating the present bay.
1980
Mangrove reserve founded
The first nature reserve in China dedicated to mangroves.
1986
National nature reserve
Raised to national level, strengthening protection of the forests.
1992
Ramsar site
Listed among the first Chinese wetlands of international importance.
Through the seasons
Spring
Warm and humid; the last wintering birds leave, and mangroves begin to flower.
Summer
Hot and wet, with typhoons; the mangroves show their role in buffering storms.
Autumn
Migrating birds return from October; calm weather suits boat trips.
Winter
Mild and dry — the best season for birdwatching, including black-faced spoonbills.
Routes and ways in
Boardwalks at Yanfeng
Raised walkways through the mangrove forest let visitors see the root systems and mudflat life at low tide.
Boat trip on the bay
Boats run through the channels between the mangroves at higher tides.
Practical notes
- Check the tides: high tide is best for boats, low tide for seeing crabs, mudskippers and the mud surface.
- Stay on boardwalks — the mud is deep and the seedlings fragile.
- Mosquitoes are common, especially around dusk; use repellent.
- The reserve lies in Meilan district, east of central Haikou and not far from Haikou Meilan airport.
Cities to start from
Frequently asked questions
Sources
- Ramsar Sites Information Service — Ramsar Convention Secretariat (retrieved 27 September 2026)
- Haikou Municipal People's Government — Haikou Municipal People's Government (retrieved 27 September 2026)
- Hainan Provincial Forestry Bureau — Hainan Provincial Forestry Bureau (retrieved 27 September 2026)
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