His scientific research and conservation campaign for the last 4 decades have been crucial to the efforts of saving the South Asian river dolphin from extinction.

A member of the IUCN Species Survival Commission[citation needed] and the National Ganga River Basin Authority, his contributions are reported in the establishment of the Vikramshila Gangetic Dolphin Sanctuary, Bhagalpur and he is a recipient of the Order of the Golden Ark of the Netherlands.

[3] The Government of India awarded him the fourth highest civilian honour of the Padma Shri, in 2016, for his contributions to environmental conservation.

[4] Prof. R K Sinha conducted surveys of the entire length of the Ganges and most of its tributaries in India and Nepal to assess the distribution, population status, ecological requirements, and threats to the dolphin.

Sri Jairam Ramesh, Union Minister of Environment and Forests, highlighted Sinha's work in the Rajya Sabha on 8 March 2011 stating, "..one of the leading authorities on dolphin is a Professor.