"We must find out the reason why they are not entering our coasts. They are going to Bangladesh. The situation was the opposite 15 years ago. We must look into it immediately," Samir Bhattacharya, an emeritus professor of life sciences at Visva-Bharati University, who is also part of the project, told IANS.
He said the rising level of pollutants in the Ganges might be a factor inhibiting the hilsa's breeding.
"Another factor is indiscriminate fishing of egg-carrying hilsa. Besides, there is a possibility that the fish might be attracted by a particular chemical called chemo-attractant present in fresh water. It may be so that the levels of that chemical has declined," Bhattacharya said.
