India, Dec. 27 -- The presence of dolphins in the Brahmaputra has long been documented. As a child, I would look forward to our visits to Guwahati so we could go to the river bank and watch river dolphins leap, play and dance. Over the years, this has become a far rarer sight with the phenomenal surge of Guwahati's growth, the building of public infrastructure and private buildings along the riverside, and the consequent pollution of the river and its smaller tributaries such as the Bharali. Indeed, the Bharali has suffered the indignity of being virtually turned into a gutter, spewing household muck and plastic bags and wrappers into the Brahmaputra. All this has played a major role in driving the dolphin population to less crowded and l...