Mangroves and intertidal habitats of the Red River Delta form wetlands of high biodiversity especially in the Xuan Thuy and Tien Hai districts.

The coastal areas of the Red River Delta support a complex system of natural, semi-natural and agricultural vegetation types.

[1] During spring and autumn migrations, huge numbers of birds stop en route from their breeding grounds in northern Asia to their wintering sites in the Indo-Malaysian and Australian regions.

Eleven of these birds fall under the category of threatened or near-threatened species, including spoonbill sandpiper (Calidris pygmaea), black-headed ibis (Threskiornis melanocephalus) and Japanese paradise flycatcher (Terpsiphone atrocaudata).

[1] In recognition of the fundamental ecological functions performed by its wetlands, Xuan Thuy was declared the first Vietnamese Ramsar site in 1982.