A comprehensive approach is needed to preserve the biodiversity of the Sundarbans and save its endangered flora and fauna, speakers told the Zoological Society of Bangladesh's 20th national conference yesterday.

Poaching, illegal trade, loss of prey, habitat degradation, navigation routes and industrialisation combined has drastically reduced the Bengal tiger population, which symbolises the 10,000 square kilometre mangrove forest, they said.

Addressing the conference, themed "Sundarban's Biodiversity: Zoological Perspective", at the Dhaka University (DU) senate bhaban, Mohammad Ali Reza Khan, principal wildlife specialist of Dubai Municipality, said tiger conservation also ensures the ecosystem's protection.

Other critically endangered species including the crocodile, masked finfoot.

black finless porpoise, river terrapin, olive ridley, hawksbill and green sea turtles; six species of sharks, anaconda and deer, said the speakers.

"We can build the Rampal power plant in any other place but never build another mangrove forest," said Ali Reza on speakers urging to bar industrialisation within 20 kilometres (buffer zone) of the forest.

"The periphery of the Sundarbans also must be protected as the boundary of a mangrove forest is not fixed," said Prof Monirul H Khan of Jahangirnagar University.

Environment and Forests Minister Anwar Hossain Manju urged for a positive approach to save the biodiversity of the Sundarbans and increase budget allocation.

DU Vice Chancellor AAMS Arefin Siddique and zoology department Chairperson Anwarul Islam and the zoological society's President Prof Khan Habibur Rahman also spoke.