Donald Macintosh, Ena Suarez, Frida Sidik, Pham Hong Tinh, Gianluca Polgar, Maeve Nightingale, Marcos Valderrabano

"The 'Mangroves of the Sunda Shelf' is a regional ecosystem subgroup (level 4 unit of the IUCN Global Ecosystem Typology in the Sunda Shelf province. It includes intertidal forests and shrublands of the marine regions of the Malacca Straits, Gulf of Thailand, southern Viet Nam and the Sunda Shelf/Java Sea. This province has a tropical climate with protracted rainfall that provides very favourable conditions for mangroves. The rich mangrove biota includes 49 species of true mangrove plants and many mangrove-associated taxa. Five mangrove species are in the IUCN Red List of threatened species.
Mangroves in the Sunda Shelf province had a mapped extent in 2020 of 12,350 km2, representing 8.4% of the global mangrove resource by area. The main threats to mangroves are conversion for agricultural and aquaculture use, or for coastal infrastructure development. These practices impact on the remaining mangroves through coastal erosion, land subsidence and pollution. Climate change (especially sea-level rise) is an additional and serious threat.
Today the Sunda Shelf mangroves cover ≈ 35% less than our broad estimations for 1970, based on country level studies; however, the rate of area loss slowed to -4.8% from 1996 to 2020 and has decelerated further since 2010. The Sunda Shelf mangrove area is estimated to decrease by 13.7% over the next 50 years. Moreover, we estimate that 3.4% of the mangroves are undergoing degradation, and this could rise to 10% over a 50-year period, based on an analysis of the decay of vegetation indexes. These estimates are very conservative; however, no other data sources were available to measure environmental degradation at the province level. More than 30% of the Sunda Shelf mangrove extent could be submerged by 2070 due to sea-level rise.
Overall, the Sunda Shelf mangrove ecosystem is assessed as Vulnerable (VU) under subcriteria A1 and C2."