SRINAGAR; 21, April 2013: After men and machines for decades failed to clean up the mirror-calm Dal Lake to remove choking weeds, lily pads and other water plants that have tarnished the image of the famed tourist attraction.

Scientists in 2004 hit upon a new low-cost idea: flood the dying lake with thousands of weed-eating Chinese grass carp.

They started it as an experiment and thought this could be the solution they have been looking for. A small number of the Chinese fish, which only eat water plants, had been released in pens at a few places in the lake in tests.

The grass carp is a voracious herbivore and an adult fish can grow up to 30 kg.

The fish is able to control the growth of weeds but the plants won’t completely vanish from the whole lake.

The UN Food and Agriculture Organisation had identified the grass carp for biological weed control and it had been successfully used in the US and Europe. “It was a serious project but we confined this only to experiment and the result is that this project failed,” said an official

The fisheries department had imported more than 10,000 fish from China and also set up a breeding centre in Kashmir.

Some expert said the fish would affect the lakes ecosystem and might not be able to attack all of the 25 different kinds of weeds that thrive in the polluted lake.

“Grass carp is selective in eating, it prefers softer weeds. The fish can change the nutrient balance of lake. Grass carp also leaves huge excreta, which would pollute it more,” Said Yaqoob Ahmad, an official of the fisheries department. The lake, which once covered 30 sq km, has shrunk to half that size over the past four decades because of silt, weeds and development.

Many areas on the periphery have been reclaimed and converted into floating gardens.

The lake, in the heart of Srinagar, has more than 1,500 timber houseboats that are popular with tourists, who also take trips in smaller boats. “The lake is like our mother, it gives us bread and butter, we survive on this. I wish and pray the lake gets healthier, cleaner… that will attract more tourists,” said houseboat owner Mohammad Ramzan, 55.

Weeds have flourished in the lake because of the large amounts of waste flowing into it. Each year, civic authorities remove more than 6,500 metric tonnes of weeds using de-weeding machines. Labourers also manually remove plants from the lake.