Indus and Ganges river dolphins (Platanista gangetica): ex situ options for conservation

The South Asian River dolphin (Platanista gangetica) consists of two subspecies, the Indus (Platanista gangetica minor) River dolphin endemic to the Indus River system primarily in Pakistan and the Ganges (Platanista gangetica gangetica) River dolphins which occurs only in the Ganges, Brahmaputra and Karnaphuli-Sangu River systems of India, Bangladesh and Nepal. The species, and both subspecies are classified as Endangered on the IUCN Red List. The Indus River dolphin is thought to number approximately 2000 individuals, fragmented into 5 different sections of river, and the species has undergone an 80% reduction in range. Since a ban on the hunting of dolphins in the 1970s the dolphin population has been increasing in abundance. The Ganges dolphin is more numerous than the Indus dolphin, has a wider range and has suffered a less drastic range decline, however the threats from fishing, high levels of industrial pollution, shipping, poaching, habitat fragmentation by barrages, flow regulation due to hydropower generation and flow depletion from diversions for irrigation suggest that its population is declining. The Indian Waterways project and proposals to link Indian river systems may cause rapid catastrophic declines in the subspecies in the future if they proceed. Platanista are not currently held in captive facilities anywhere in the world. In the 1970s a total of 16 Platanista were maintained in international captive facilities, 4 at the Steinhart Aquarium in the USA (Indus dolphins), 7 at the Berne Institute of Brain Anatomy in Switzerland (Indus dolphins) and 5 at Kamogawa Sea World in Japan (Ganges dolphins). Survivorship was poor, ranging from a few weeks up to approximately 3 years and no breeding ever occurred. A variety of rescue programmes to capture and translocate Platanista from canals and channels suggest that this species is relatively robust to capture and transport, however suspected capture myopathy has occurred in a number of individuals. There is very little technical or infrastructure capacity for holding captive cetaceans in South Asia at present, the quality of care and husbandry in most zoos is extremely poor, and in India the keeping cetaceans in captivity for entertainment has been prohibited.