They said the existence of lives depends on biodiversity, but the unchecked water pollution and population pressure are threatening the biodiversity.
Poribesh Bachao Andolan (Poba) organised the human chain in front of the Fine Arts Institute of Dhaka University in the morning.
Chaired by Poba secretary Engr Abdus Sobhan, the programme was addressed, among others, by Modern Club president Abul Hasnat, Bangladesh Peace Movement president Prof Kamal Ataur Rahman, Poba coordinator Atiq Murshed and environmental activist Mahbubul Haque.
A set of recommendations was put forward from the human chain programme to check water pollution in the country. The recommendations include halting industrial pollution and use of pesticide in agriculture, reducing use of surface water and ensuring equitable sharing of waters of the common rivers.