Panaji, Sep 6 (IANS): Biological pollution, especially e-coli, is a matter of concern in Goa's coastal areas, particularly its rivers, an expert said here.

"Many of the in-shore waters, where flushing is not adequate, their number (e-coli pathogens) is rising and of concern," Dr. S.W.A. Naqvi, outgoing Director of the Goa-based National Institute of Oceanography (NIO), said.

He told IANS that the pollution was largely caused due to un-treated municipal waste being pumped into water-bodies.

Scientists and pollution monitoring agencies have in the past warned about excessive pollution in Goa's rivers.

A study published in 2015 by the Goa State Pollution Control Board stated that water in most of rivers in Goa, especially flowing through urban areas, was unsafe for human consumption with faecal coliform traced to up to 90-100 mgpl, while 30 mgpl is considered normal.

The report also said the most important river in the state, the Mandovi, was also the second-most polluted after the Sal river in south Goa, where another study conducted by the NIO found traces of cadmium -- a poisonous chemical commonly found in car batteries -- in oysters.

"The major conclusion of the project is that the pathogen counts along the Indian coast are higher than normal, which means that this is being affected by bacterial pollution. We analysed some samples (in the Sal river) and found that the bacterial, e-coli count in those samples were very high.

"Fortunately, no one consumes them (oysters) raw and you normally cook them for a long time so that takes care of the pollution," Naqvi said.