By Our Staff Correspondent

PANTNAGAR (UTTAR PRADESH), APRIL 7.

Gambusia afinis - a fish species popularly used to control mosquitoes in the ponds and lakes located in the warm areas of the plains and inadvertently introduced in the Naini Tal lake - is bound to finish the fish population and the beauty of the lake, if not removed immediately.

Gambusia afinis feeds on zoo plankton which eats phyto plankton. The introduction of gambusia afinis in this lake, where mosquitoes are not found, has altered the food chain, resulting in a phenomenal rise in the level of algae. The increased level of algae has led not only to pollution but decreased the level of oxygen leading to fish mortalities not only in winters but also in summers.

According to Dr. A. P. Sharma and Dr. U. P. Singh of the College of Fishery Sciences at the G. B. Pant University of Agriculture and Technology here, the Naini Tal lake, which is now the most polluted lake in the country, would be no more than a pool of extremely dirty water in another 25 years if steps to cleanse it were not taken on a war footing.

The varsity experts introduced Silver Carps known to be good phyto plankton eaters and are optimist about succeeding in controlling it in the coming years.

They have also suggested reintroduction of the once commonly found Mahaseer and Snow Trout in the lake.

To avoid mass mortality of fish due to lack of oxygen, the experts have suggested setting up of an aeration system. Once installed, this will ensure a pollution free lake for a long time.

Fish apart, the Naini Tal lake which is the main drinking water source, is also the dumping ground for the town's sewer and garbage. The rate of siltation has also gone up tremendously due to unscientific and illegal cutting of the hill sides around the lake by colonisers. Although efforts to stop the illegal building menace were made by the former Governor, Mr. B. Satyanarayana Reddy, the builders continue to plunder the hill sides with the help of corrupt officials, alleged several shopkeepers around the lake.