Praschag et al. (2007, 2008) demonstrated that the widespread species Batagur baska comprised at least two genetically distinct species, and separated out B. affinis for the southern species occupying southern Thailand, Peninsular Malaysia, and Sumatra in Indonesia, retaining the name B. baska for the more northern species from India, Bangladesh, and Myanmar.

Batagur baska, has declined from abundant in the 19^th century to likely fewer than 100 mature animals remaining. All remaining wild subpopulations have fewer than 50 mature individuals and have had observed declines qualifying for listing as Critically Endangered (CR) under criteria C1+2a(i). At an estimated generation time of 25 years (by analogy with B. affinis), total population decline has exceeded 90% over the past three generations (here estimated as three times the time of maturity) as a result of exploitation of eggs and adults as well as habitat loss, degradation and fragmentation and the decline is projected to continue into the future, hence the species also qualifies for listing as CR under criteria A2acd+4cd. 

Batagur baska once ranged from Orissa and West Bengal in India through Bangladesh and Myanmar (lower Ayayarwady, Sittaung and Thanlwin [Salween]), and possibly as far south as the Andaman Sea side of Thailand at the Kra river. It is now limited to the Sundabans area of India and Bangladesh, with three females in two different temple ponds in Myanmar (S. Singh and P. Praschag pers. comm. 2018). Populations of river terrapins in Southeast Asia previously referred to this species are now considered a separate closely related species, the Southern River Terrapin (Batagur affinis).

In the 1980s a moderate to large breeding population of Batagur baska was thought to exist in the Sunderbans of Bangladesh (Moll 1985). It was considered uncommon and Critically Endangered by 2000 (Rashid and Khan 2000). There are no records of adults in recent years, with only some hatchlings caught (P. Praschag pers. comm 2018). There are 8 females and about 26 males, with 230 juveniles in captivity (P. Praschag pers. comm. 2018).

Populations of Batagur baska in the Sunderbans in India were considered abundant in the 19th Century, but had declined to very small populations by the 1970s (Moll 1985) and to an estimated 10 breeding females by 1995 (Choudhury et al. 2000). The total Indian population was estimated as fewer than 40 animals, with about three nests produced per year, although there was hope that more animals and/or nesting sites might exist and be found with intensive survey efforts (Lucknow Red List Workshop participants, 2005). Participants at the 2011 Singapore Red List Workshop estimated that about 30 adult animals remained. In India, there are 8 males and 7 females; and 300 juveniles in captivity (S. Singh pers. comm. 2018).

Myanmar: Historically Batagur baska was numerous in the Ayeyarwady delta in Myanmar (Maxwell 1911), but populations had declined to a few nesting animals in the early 1980s (Moll 1985) and there are apparently no records from the wild in recent years, despite surveys. Currently, only three females remain in two pagoda ponds (P. Praschag pers. comm. 2018).

In Austria, there are two males, three females and 15 juveniles held in an assurance colony (P. Praschag pers. comm. 2018).

Batagur baska is a highly aquatic turtle species, associated with estuarine river sections, with nesting taking place on large on sand banks. It feeds primarily on riverside plants and fruits, however, it also consumes molluscs and has been observed to accept a variety of animal matter in captivity (Moll 1980). Females mature at 45 cm carapace length and may reach 60 cm; males mature at around 40 cm carapace length and can reach up to 49 cm (Moll 1985). Breeding maturity may occur at an age of nine years in captivity, but requires up to 25 years in rivers with modest productivity (Moll 1980). Females only produce a single clutch per year of about 18-33 eggs (P. Praschag pers. comm. 2018).

Batagur baska has been exploited long-term for local subsistence and ritualistic consumption as well as some regional trade, including supply to the Calcutta markets in the 19^th and 20^th centuries. Harvest of its eggs has been extensive as the eggs are highly prized for consumption and can be collected at known sites at predictable times.

The species’ use of estuarine and mangrove habitats and sandy nesting beaches means it has been significantly impacted by habitat loss, as estuaries are prime locations for human settlement and industrial development, mangrove areas are cleared for fuelwood and for shrimp and other aquaculture development, and sandy banks and beaches are exploited for sand as building material and tourist developments.

The extent of threat posed by entanglement in fishing nets, the effects of altered water flow from hydrological mega-projects (dams, reservoirs, river diversion) on nesting sites and habitat in general, or habitat pollution, have not been documented as specific threats, but have likely impacted the species.

Seizure records from illegal trade have reported both B. affinis and B. baska as ‘Batagur baska’; at least 139 live specimens of one of these two species were reported as seized from 6 illegal trade shipments during the period 2000-2015 (CITES CoP17 Doc73). 

Batagur baska has been heavily exploited for its flesh and eggs, typically for local subsistence and ritualistic consumption. 

Batagur baska has been included in CITES Appendix I since 1975, prohibiting all forms of international commercial trade. It is also protected under Schedule I of the Indian Wildlife (Protection) Act of 1972 (amended), which includes endangered species that may only be hunted under exceptional circumstances, under licence from both federal and provincial authorities. Myanmar formerly had laws controlling egg collection, but with near extirpation of the terrapin within the country, such laws are now antiquated (Moll 2009). Marine and freshwater turtles are included in the Myanmar Fishery Law, and Myanmar Protection of Wildlife, Wild Plants and Conservation of Natural Areas Law of 1994, however, wildlife laws in Myanmar are poorly enforced. Batagur baska is not listed under the Bangladesh Wildlife Preservation (Amendment) Act (BWPA) 1974.

Batagur baska has been recorded from Sunderban Tiger Reserve (W Bengal) and Bhitarkanika Wild Life Sanctuary (Orissa) in India (Hanfee 1999), and is apparently now extinct at the latter site (Lucknow Red List Workshop participants 2005).

The species has historically received some captive management efforts in India. The Sundarbans subpopulation receives significant unofficial protection from the tiger and dense mosquito populations inhabiting the Sundarbans, but with tiger poaching at an all-time high, this effect may have disappeared.

Ensuring the survival of Batagur baska in the wild will require strict implementation of existing protective measures for the last remaining populations, vigilant protection of remaining habitat for these populations, and further coordinated population management and restoration efforts, including captive breeding and headstarting. Working with local communities to reduce and eventually eliminate egg poaching appears essential. The opportunities for a major Bangladesh-India transboundary conservation project for the Sundarbans, targeted for funding by the UNDP, warrant investigation.

Moll et al. (2009) suggested that unless some previously unknown viable population is discovered, captive breeding programs may be necessary for remaining wild individuals until such time that it is feasible to reestablish a wild population within sanctuaries (Moll et al. 2009).