AGNIMIRH BASU

more than 40 gharials were found dead downstream in the Chambal river, ahead of its confluence point with the Yamuna. Preliminary reports indicated liver cirrhosis was among the causes of the deaths, said D N S Suman, chief wildlife warden of Uttar Pradesh.

According to GSridhar, divisional forest officer, wildlife, National Chambal Sanctuary, heavy metal pollution may have caused the liver cirrhosis.

“Floods in the Yamuna in 2007 may have carried heavy metals either through the backflow or fish population, which the gharials consumed. There was no contamination found upstream of the Chambal river,” he says.

Conservationists are concerned because the deaths were species-specific. Only gharials that were over 10 years—the breeding age—and above six feet in height died. The death occured only among the natural population and not the captive bred lot, a forest official said. “The viscera should be sent for toxicological studies to find out why mortality was so species-specific. This could affect the declining adult population,” says B C Choudhary, a scientist at Dehradun-based Wildlife Institute of India.

The gharials’ status was recently changed to “critically endangered” category (see ‘Croc can’t go on’, Down To Earth, November 30, 2006).