Current view: Text account
Site description (2004 baseline):
Site location and context
The IBA comprises a 195 km-long section of the coastal zone of the Inner Gulf of Thailand, from Laem Phak Bia in the west to Chonburi in the east. Four major rivers, the Mae Klong, Tha Chin, Chao Phraya and Bang Pakong, discharge into the Gulf of Thailand along this stretch of coastline, creating extensive areas of intertidal habitats. The site includes an estimated 23,500 ha of intertidal mudflats, extending over 2 km from the shoreline at low tide in places. Previously, the Inner Gulf of Thailand supported a large area of mangroves. However, this habitat has now been extensively converted to other land uses, and, currently, less than 1,600 ha of mangroves remain, much of which consists of regenerating Avicennia-dominated scrub. Areas that previously supported mangroves now support anthropogenic habitats, including at least 10,600 ha of saltpans and from 40,000 to 80,000 ha of shrimp ponds, many of which are abandoned. Inland of the intertidal zone, the site supports large areas of Suaeda-dominated coastal flats, fish-ponds and rice paddies.
Due to high levels of human use and high human population densities, it is unrealistic for more than a small part of the site to be placed under strict conservation management. However, the whole site was defined as a single IBA, because conservation actions aimed at controlling over-exploitation of natural resources and promoting compatible forms of land use are required across the whole site. In 2001, an 87,500 ha section of the IBA around Don Hoi Lot in Samut Songkhram province was designated as a Ramsar Site.
To date, there have been no comprehensive surveys of the avifauna of the entire IBA. Rather, most available data are from individual sites within the IBA, including Bang Poo, Wat Asokaram, Kalong, Rangchan, Khok Kham, Don Hoi Lot, Klong Khon, Bangtabun, Ban Laem and Laem Phak Bia.
The Inner Gulf of Thailand is one of the most important sites for migratory waterbirds in mainland South-east Asia. Between 150,000 and 300,000 birds are estimated to use the site annually, the majority feeding on the highly productive intertidal mudflats. Over 100 waterbird species have been recorded at the site, including seven species of duck, 50 species of wader and 18 species of tern or gull. Species recorded at the site include 13 globally threatened species, of which at least four are thought to regularly occur in significant numbers: Nordmann's Greenshank Tringa guttifer, Spoon-billed Sandpiper Calidris pygmeus, Greater Spotted Eagle Aquila heliaca and Spot-billed Pelican Pelecanus philippensis. In addition, three globally near-threatened species regularly occur at the site in significant numbers: Asian Dowitcher Limnodromus semipalmatus, Malaysian Plover Charadrius peronii and Painted Stork Mycteria leucocephala. Furthermore, at least 10 waterbird species occur at the site in concentrations higher than 1% of the Asian biogeographic population, underlining the site's international significance.
Non-bird biodiversity: Fish
Freshwater Sawfish Pristis microdon (CR)
The IBA comprises a 195 km-long section of the coastal zone of the Inner Gulf of Thailand, from Laem Phak Bia in the west to Chonburi in the east. Four major rivers, the Mae Klong, Tha Chin, Chao Phraya and Bang Pakong, discharge into the Gulf of Thailand along this stretch of coastline, creating extensive areas of intertidal habitats. The site includes an estimated 23,500 ha of intertidal mudflats, extending over 2 km from the shoreline at low tide in places. Previously, the Inner Gulf of Thailand supported a large area of mangroves. However, this habitat has now been extensively converted to other land uses, and, currently, less than 1,600 ha of mangroves remain, much of which consists of regenerating Avicennia-dominated scrub. Areas that previously supported mangroves now support anthropogenic habitats, including at least 10,600 ha of saltpans and from 40,000 to 80,000 ha of shrimp ponds, many of which are abandoned. Inland of the intertidal zone, the site supports large areas of Suaeda-dominated coastal flats, fish-ponds and rice paddies.
Due to high levels of human use and high human population densities, it is unrealistic for more than a small part of the site to be placed under strict conservation management. However, the whole site was defined as a single IBA, because conservation actions aimed at controlling over-exploitation of natural resources and promoting compatible forms of land use are required across the whole site. In 2001, an 87,500 ha section of the IBA around Don Hoi Lot in Samut Songkhram province was designated as a Ramsar Site.
Pressure/threats to key biodiversity
The main threats to biodiversity at the site are hunting, disturbance to birds, pollution, over-harvesting of fish and shellfish, and habitat loss, of which the last is perhaps the most significant. One of the main causes of habitat loss is afforestation of intertidal mudflats with mangrove, with the objective of coastal protection against storms. Afforestation reduces the available area of intertidal mudflats for feeding waders. Other causes of habitat loss include reclamation, land speculation, urban expansion and industrialisation.
Recommended citation
BirdLife International (2024) Important Bird Area factsheet: Inner Gulf of Thailand (Thailand). Downloaded from
https://datazone.birdlife.org/site/factsheet/inner-gulf-of-thailand-iba-thailand on 22/11/2024.
