In aquatic environments, like the inland rivers in India, the waters are muddy. The visibility is poorer in these parts from more clearer blue oceanic waters. Many of the animals living in these waterways rely far more on sound than sight for their survival. The noise made by aeroplanes, ships and cars are examples of human-made noise on air, water and land. Underwater noise that comes from the navigation systems of river vessels, called sonar and their propellers interferes with the vocalization of aquatic animals for foraging for food and detecting their immediate environment.
This, according to a team of researchers at National Centre for Biological Sciences (NCBS), Ashoka Trust for Research in Ecology and the Environment (ATREE) and Mie University in Japan, is a glimpse of the situation unfolding in river Ganga.