A population assessment survey of the endangered Ganges river dolphin was made between February and Apil 2005 in the Brahmaputra River starting from Assam-Arunachal border to the India-Bangladesh border. One hundred and ninety seven dolphins were recorded in the entire 856 km river stretch with an encounter rate of 0.23 dolphins per km.
Original Source [2]
Links:
[1] http://admin.indiaenvironmentportal.org.in/feature-article/status-and-distribution-endangered-gangetic-dolphin-platanista-gangetica-gangetica
[2] http://www.currentscience.ac.in/Downloads/article_id_097_08_1143_1151_0.pdf
[3] http://admin.indiaenvironmentportal.org.in/category/author/abdul-wakid
[4] http://admin.indiaenvironmentportal.org.in/category/journal/current-science
[5] http://admin.indiaenvironmentportal.org.in/category/thesaurus/assam-valley
[6] http://admin.indiaenvironmentportal.org.in/category/thesaurus/brahmaputra
[7] http://admin.indiaenvironmentportal.org.in/category/thesaurus/dolphin
[8] http://admin.indiaenvironmentportal.org.in/category/thesaurus/endangered-species
[9] http://admin.indiaenvironmentportal.org.in/category/thesaurus/wildlife
[10] http://admin.indiaenvironmentportal.org.in/category/thesaurus/illegal-trade
[11] http://admin.indiaenvironmentportal.org.in/category/thesaurus/poaching
[12] http://admin.indiaenvironmentportal.org.in/category/thesaurus/public-participation
[13] http://admin.indiaenvironmentportal.org.in/category/thesaurus/india