Ganges River Dolphins are generally concentrated in counter-current pools below channel convergences and sharp meanders (Kasuya and Haque 1972, Smith 1993, Smith et al. 1998, 2000) and above and below mid-channel islands, bridge pilings, and other engineering structures that cause scouring (Smith et al. 1998, Smith and Reeves 2012). Dolphins appear to prefer river sections with thalweg depths of 5–12 m in larger river channels (Kelkar et al. 2010). In shallower tributaries, dolphins were found in river channels with depths from 2.5 to 5 m (Choudhary et al. 2012). River dolphin site-fidelity to counter-current pools is probably the greatest in fast-flowing channels (Smith et al. 1998). Annual monsoon-driven floods cause great variability in the amount of available habitat. The dolphins generally expand their distribution to include small tributaries or braided channels in the high-water season and then shrink their distribution to larger channels during the dry season (Haque et al. 1977, Mohan and Kelkar 2015). Isolation in seasonal lakes sometimes occurs (especially in the Brahmaputra basin), as does "escapement" into artificial water bodies such as canals and reservoirs. Deltaic (brackish) waters are a major component of the total range, but Ganges River Dolphins do not usually occur in coastal waters, except occasionally in river mouths during low tide and during the monsoonal flooding or high-water season when salinity declines (Smith et al. 2009, 2010). Information on the physiology, anatomy, behaviour, and sensory ecology of the species is mainly available from field specimen collections and captive studies from the 1970s (e.g. Herald 1969, Pilleri 1971, Kasuya 1972). Ganges River Dolphins use high-frequency echolocation clicks, with relatively low sound source levels compared to marine dolphins. Ganges River Dolphins forage on small fish and shrimp (Ura et al. 2007, Jensen et al. 2013, Kelkar et al. 2018). The dolphins are largely solitary, with mother-calf pairs as the only obvious social grouping, and little is known about social interactions (Sutaria et al. 2019, Braulik et al. 2020).

The main known range declines have been in the Son, Sind, Ken, and Betwa Rivers, which are peninsula-origin rivers, and in Himalaya-origin rivers such as the Yamuna, Ramganga, and Sharda, and upstream reaches of the Ganges River in the north Indian plains (Sinha et al. 2000, Sinha and Sharma 2003, Sinha and Kannan 2014, Singh et al. 2014). These southern tributaries have multiple dams, and dry-season flows have been reduced to almost zero. A range reduction of about 15% for the Ganges River main stem (in the Haridwar-Bijnor and the Narora-Kanpur segment) is evident. No dolphins have been reported in recent years between the Madhya Ganga Barrage at Bijnor and the Bhimgoda Barrage near Haridwar (100 km), thought to be the upstream limit of their historical range in the Ganges in the late 1800s (Sinha et al. 2000). The 345 km stretch between the Narora and Kanpur barrages on the Ganges supports only 15-20 individuals. (Behera et al. 2013, 2014; WWF-UPFD 2015, WII-GACMC 2017).  In major northern tributaries of the Ganges (Ghaghra (Karnali in Nepal), Gandak (India), Kosi (Koshi in Nepal), and Mahananda (India)), dolphin populations are still extant, although minor range reductions have occurred upstream and downstream of barrages. Anderson (1879) mapped the possible range of Ganges River Dolphins to include the Yamuna River until Delhi. The dolphin population in the Yamuna River has undergone a range reduction of 40% (from Delhi to Firozabad) and the remaining population is small (estimated at 40 animals from Etawah to Allahabad: Behera et al. 2014, Taigor 2020), and seriously threatened by poor flows and pollution especially upstream of Etawah. In the Karnaphuli-Sangu basin, a range reduction of about 40% is estimated to have occurred after the construction of the Kaptai Dam (Smith et al. 2001). In the Buriganga and Turag Rivers in Bangladesh, a population reduction of about 70% is estimated to have occurred during the last 40 years due to habitat loss from industrial pollution and vessel traffic (Alom, unpublished). The smallest range decline is in the Brahmaputra River and its undammed tributaries in India. Wakid (2005) reported dolphins only from the Kulsi and Subansiri tributaries of the Brahmaputra, and no dolphins were recorded in ten others. Of these ten, Anderson (1879) had included the Manas, Kameng or Jia Bhareli, Dhansiri, and Kopili in the inhabited range shown in his map.  Choudhury et al. (2019) reported the extirpation of dolphins in the Barak River (90 km) in Assam (India), a tributary of the Meghna River, which they attributed to a combination of bycatch in fishing nets, and water pollution. No range reductions have been reliably documented in Bangladesh, except for the upper Karnaphuli above the Kaptai Dam (Smith et al. 2001). In Nepal’s rivers, range reductions have been reported for the naturally range-restricted (due to the Himalayan foothills) populations in the Karnali and Narayani rivers (Paudel et al. 2015a, Khanal et al. 2016). In Nepal’s Narayani River, the population is fewer than 2 or 3 animals, and dolphins are extirpated from the Mahakali (Sharada) River (Paudel et al. 2015a).

Ganges River Dolphins are legally protected from hunting and deliberate injury/disturbance in all range-states where they occur. India’s Wildlife Protection Act, 1972, Nepal’s National Parks and Wildlife Conservation Act 2029 (1973) and Aquatic Animal Protection Act 1960, and Bangladesh’s Wildlife (Conservation and Security) Act, 2012, afford the highest level of protection to the species. Protected areas where Ganges River Dolphins occur cover only a minor part of their range. Dolphin conservation in legally protected areas is often ineffective, because of poor or limited law enforcement, lack of community engagement, and financial and technical constraints on sustained monitoring. Existing protected areas where Ganges River Dolphins occur include the 1) Vikramshila Gangetic Dolphin Sanctuary, Bihar, India (70 km, designated in 1991); 2) National Chambal Sanctuary, Rajasthan-Madhya Pradesh-Uttar Pradesh, India (425 km); 3) Kaziranga National Park (NP), Dibru-Saikhowa NP and Orang NP in Assam, India, 4) Bardia NP in Nepal (although no dolphins are reported in the Geruwa river channel at present) and Katerniaghat Wildlife Sanctuary (WLS) in India on the Ghaghra (Karnali in Nepal) River; 5) Hastinapur Wildlife Sanctuary (Uttar Pradesh, India), 6) Sundarbans Tiger Reserve (West Bengal-India), and 7) three dolphin sanctuaries or conservation areas in the Bangladesh Sundarbans. The degree of effectiveness varies with respect to the level of active monitoring and management. Qureshi et al. (2019) found greater calf abundance and recruitment in the Kaziranga National Park stretch as compared to upstream sections of the Brahmaputra River in India. Kelkar (2015) did not find differences in river dolphin densities upstream and downstream of the Vikramshila Sanctuary. The Vikramshila Sanctuary covers a 65-70 km segment of the Ganges River. Dolphin sanctuaries in the Bangladesh Sundarbans focus on protecting deep pool habitat where river dolphins aggregate (Smith et al. 2010). Some smaller tributaries that flow through protected areas for terrestrial wildlife might also have small populations of Ganges River Dolphins. Increasingly, community-based protected areas and reserves are being considered in all range countries (Sinha et al. 2010). Such approaches have had mixed success (see Choudhary et al. 2015, Kelkar 2015, 2018).

Braulik et al. (2020) recently reviewed prospects for ex situ conservation and translocations for Platanista, which are currently not held in captivity anywhere. They noted that while ex situ conservation is not an urgent need for either Indus or Ganges Dolphins, both species face significant and immediate threats. There is a definite need to build technical capacity towards rescue, translocation, and captive holding of these cetaceans (in case of need) in all range countries, where such capacity is at present almost non-existent. In the present range, the potential for creating semi-natural reserves to have insurance populations, as in the case for Yangtze Finless Porpoises, is limited. The Ganges-Brahmaputra river basins do not have many large ox-bow lakes in the river floodplains as in the Yangtze basin. On rare occasions, Ganges Dolphins may occupy such ox-bow lakes for short periods during the flood season (e.g. Pilleri 1970). Dam reservoirs, due to their deepwater habitat features and operations for multiple human demands, are not appropriate habitat to be able to establish insurance populations of Ganges River Dolphins. Preservation of in-river populations thus remains of critical importance and topmost priority.

Earlier studies proposed alternatives to the use of dolphin oil as a fish attractant including oil from fish scraps and sharks (Mohan and Kunhi 1996, Smith et al. 1998, Mohan et al. 1999, Bairagi 1999, Sinha 2002). Fishers have also tried using palm oil and vegetable oil along with fish oils (Dey, S., pers. obs.), with trials attempted in the Vikramshila Sanctuary (Dey et al., unpublished), and in the Brahmaputra River (Qureshi et al. 2018). Reports on the effectiveness of these oils as compared to dolphin oil have been equivocal, and the uptake of alternatives by fishers remains limited.

Quantitative data on the magnitude of catches, either deliberate or incidental (bycatch), are needed as a matter of priority. Such data are unlikely to become available in the absence of well organized, adequately funded, and transparent fishery/wildlife management systems. For bycatch reduction, the use of pingers has been attempted for various cetacean species. From 61.8 hours of theodolite tracking data recorded during 75 sightings of Ganges River dolphins in the Bangladesh Sundarbans, Smith (2013) found that 70 kHz, 145 decibel pingers had limited effectiveness in displacing dolphins from the device.

In 2010, India declared the Ganges River Dolphin its “National Aquatic Animal”, and a Conservation Action Plan (2010-2020) was prepared (Sinha et al. 2010b). However, only some recommendations have been implemented. In 2015–2016, the Compensatory Afforestation Fund Management and Planning Authority (CAMPA), Government of India, funded the Wildlife Institute of India to conduct a five-year species recovery project on Ganges River Dolphins. Statewide dolphin surveys have been completed in many areas with the participation of state forest departments and conservation agencies (WWF-UPFD 2015, Qureshi et al. 2018, CMS 2020). Recently, the Ministry of Environment, Forests, and Climate Change, Government of India has announced “Project Dolphin” for the conservation of marine and river dolphins.

A Concerted Action Plan for Ganges River Dolphins was approved at the Convention on Migratory Species 13^th Conference of Parties in Gandhinagar, India (2020), which aims to promote conservation and research activities on dolphins in trans-boundary regions.