More information filtering in from the Etawah base camp of River Watch (a GCA-WWF-India initiative):
Death toll: 95
Available evidence is consistent that it was a single event that caused this die-off of gharial and not a continuing one. Meaning something happened probably months before the first week of Dec that continues to kill gharial, although at a decreasing rate now. There is no indication of infectious disease. So the focus now rests on toxins. It causes the kidney to malfunction resulting in a lethal build up of uric acid in all the joints of the body, a condition known as gout. It is so painful that the animals are unable to move – they cannot even haul themselves out of the water to bask during a time of record low temperatures. Dead animals were covered with algae, a sign that they had not left the water for some time. Members of the team say it is really sad to watch the dying animals as they roll in the water, seemingly unable to float the right way up.
The Chambal flows into the Yamuna most of the year. However, during the monsoon, the Yamuna flows into the Chambal for several kilometres. The toxic poisoning of the relatively clean Chambal could have very well occurred then. A recent colliform count for the Chambal was 21 while that of the Yamuna was 14,000! There was a fish die-off within the last 2 days in the Yamuna.
Along side these indications, there seems to be an enormous ecological upheaval in the making. Tilapia, an invasive fish from Africa, seems to be making visible inroads into the Chambal from the Yamuna. The implications for the fish predators of the Chambal is unknown.
The dead gharial found yesterday was unusual in having no fat deposits and appeared to have not fed for a long time.
Four gharial of the same size class as the dead gharial were captured yesterday in the Ajab Singh Kheda stretch of the Chambal River for detailed veterinary examination.
Over the next few days histopathological reports are expected.
Agencies and Institutes actively collaborating on this:
Forest Departments of UP and MP
River Watch (GCA-WWF-India)
Madras Crocodile Bank/Centre for Herpetology