Patna: All along the stretch of India's holiest river Ganga, the zooplanktons that play a critical role in its food chain are developing tumours, says a biologist.

M. Omair from the University of Michigan in the US has collected zooplankton samples from Haridwar, Kanpur, Allahabad, Varanasi, Patna, and Kolkata. He found that many of the zooplanktons that are eaten by the small fish have tumours.

The small fish are in turn eaten by the bigger fish and so on, so the ill zooplanktons are getting into the entire food chain, including humans who eat fish from the river.

"It is a bad sign for the environmental health of the Ganga," Omair said at a seminar held here Saturday. "If the zooplankton are gone, nothing will be left in the river."

Omair said all the zooplankton samples collected at various points along the Ganga were analysed in a lab in the US.

The Central Pollution Control Board has declared the Ganga water unfit for drinking along its entire stretch on the Indian plains downstream from Haridwar. At many places, the water has been declared unfit for bathing as well, though it is considered a holy act by Hindus.

Along most of the stretch, the concentration of coliform bacteria is higher than permissible under Indian law, and many times higher than guidelines set by the World Health Organisation.

"Garbage is dumped into the river, contributing to the growth of bacteria," a scientist said.

According to an estimate, during its 2,510 km long journey from Gaumukh to the Bay of Bengal, nearly one billion litres of untreated sewage flows into the river.

In Patna alone, about 29 drains discharge 190 million litres of sewage into the river every day, according to a study by an environmental scientist at the Patna-based A.N. College.

Over Rs.15 billion has been spent on the Ganga Action Plan - meant to clean the river - since its inception in 1984. But the pollution level has gone up since then. The second phase of the project will start next year.

Speaking at the same seminar, another scientist from the University of Michigan, Mike Wiley, stressed on the need for sharing data among the central and state governments, universities, NGOs, experts and the community involved in cleaning the river.

"All of them should share data on various aspects to achieve the goal of a pollution free river," he said. IANS