The number of sick birds, both wild and domesticated, continues to mount at the Sukhna lake in Chandigarh, with the UT wildlife department rescuing a large egret and a domesticated goose on Monday. While the egret showed signs of weak legs and was unable
to fly, the goose was on the verge of collapse displaying sign of shivering and a drooping neck.
With Monday’s rescue operation, the number of sick domesticated geese which live near the Lake Club has gone up to four. Twelve migratory wild birds have died since January 13 out of which the UT Wildlife department has managed to recover only nine, with two
Spotbill ducks and a likely wood sandpiper going missing within hours of their discovery in the Sukhna marshes on January 13.
Along with the rescue operations, a team of expert bird trappers of the Bombay Natural History Society (BNHS) netted a Greylag goose, a Coot and a Northern Shovellor for blood sampling. The samples from a Ruddy Shelduck (Brahminny duck) trapped on Monday by
Ali Hussain have been sent to the Regional Disease Diagnostic Laboratary at Jalandhar.
BNHS veterinarian Dr Debojit Das, who examined the sick geese, said, "The birds were displaying symptoms of a nervine disorder that is common to avian diseases like botulisim and cholera. This means the birds’ functioning is affected by a nervous disorder that
reveals itself in symptoms like it going in circles or trying to look skywards.
Water pollution in Sukhna could be a possible cause. Dead storage level and pollution level in the Lake has been rising.
UT Wildlife Department might have acted fast in the matter concerning the death of migratory birds, but it is yet to explore the role of Sukhna’s water in the rising mortality of birds. Water quality of the Lake, experts in water conservation area say, might
have solutions to the mystery behind the death and sickness among the flocking birds. Very often, fall in the levels of dissolved oxygen in water has been found to cause bird mortality.
In case of Sukhna, therefore, testing of water samples is an absolute necessity. Over the past, pollution levels in the Lake have raised rapidly on account of several reasons, main being the rise in dead storage level of the Lake. Dead storage level is the
level below which water cannot be drained out of the Lake. Water present below this level is always highly polluted because it gets saturated with toxic elements and gets devoid of dissolved oxygen present in water.
The same might be true in case of Sukhna Lake where dead storage level currently stands at elevation -- EL 1151 feet. There was a time when the level was 1148 feet, but the same has risen over the past due to increase in water level of the Lake by three
feet. Naturally, more and more water under the dead storage level would have become concentrated, making it unhealthy for aquatic life.
Another reason why Sukhna’s water has become highly polluted is that the Lake’s spill away gates were last opened in the monsoon season of 2005. That is more than one and a half years earlier. During 2006, there was no escape of water from the Lake at all.
This has led to increased level of toxicity in the water and this toxicity, in turn, could cause sickness and death among birds, unless detected otherwise.
Admitting to the possibility of water pollution behind the death of birds, Mr G.S. Dhillon, water resources expert, said a similar problem had once arisen in Harike Lake. "In certain pockets of the Lake, migratory birds were found dying without apparent
symptoms. We sampled the waters from those pockets and sent them to Irrigation and Power Research Institute at Amritsar for testing. We found that water was so toxic and so deprived of oxygen that no aquatic or any other form of life could exist. For years,
decaying organic matter had caused the absence of dissolved oxygen in water, leading to death of birds. Finally, water had to be pumped out of the Lake and fresh water introduced."
The same institute can be asked to conduct water sample testing of Sukhna.
SOURCE : The Tribune, Monday, January 29, 2007 and Times of India, Tuesday, January 30, 2007