• Penalize polluters as per “Polluter pays principle”
• Restrict the nutrient discharge into the lake;
• Allow only treated water into the lake;
• Maintain macrophytes through regular harvesting and restrict the region infested with weeds

To control the growth of algae dominated by spirulina spp the following fish species should be introduced into the lake

Silver Carp, Bighead carp and Sandkhol Carps are introduced to fresh water systems because of their ability to decrease phytoplankton (algae) density although zooplanktons are preferred food.

Hypophthalmic molitrix (Common Name: Silver Carp)
Silver carp belongs to the family Cyprinidae (the minnow and carp family). The genus name, Hypophthalmic is a Greek word (“hypo” means “under”; “ophthalmos” means “eye” and “ichthys” meaning “fish”). The silver carp was first named by Valenciennes in 1844.
The silver carp is a deep-bodied fish, laterally compressed. They are silvery in color when young and as they become older they fade from a greenish color on the back to silver on the belly. They have very tiny scales on their body, the head and gill area are scale-less. They have a large mouth, but toothless (has pharyngeal teeth) with upturned lower jaw. Its eyes are forward that sits below the mouth and project downward. Silver carp can grow to over three feet in length and to nearly 100 pounds.

Sliver carp are filter feeders that eat phytoplankton, zooplankton, bacteria, detritus and they graze on aquatic vegetation. They live in freshwaters that are standing or slow flowing. They breed at the age of 3 years to 10 years. The spawning occurs anytime between April and September when the temperature is between 18-20 degrees Celsius.
Aristichthys nobilis (Richardson 1845) [Common Name: Bighead Carp, Belli-gende (India)]
Bighead Carp belongs to the family Cyprinidae. Big head carps are dark green to olive in color on their backs. They have gray to silvery sides, with a white to cream colored belly. The scales are very tiny, and the eyes are set below the midline of the body. The body of a big head carp is long and compressed. The head is very large compared to the body, so its name, the big head carp. Its head has no scales, a large mouth with no teeth, and a protruding lower jaw. The bighead carp has a smooth keel between the anal and pelvic fins that does not extend anterior of the base of the pelvic fins. They can weigh from 25-50 kg. Big head carp can be up to 1.5 meters long. The big head carp have long and comb-like gill rakers,

Bighead carp can tolerate salinities in the range of 6-12 parts per thousand. The preferred temperature for reproduction is about 25ºC, the maximum temperature in which bighead carp can survive is 38 ºC. Bighead carp can also survive temperatures down to nearly freezing, on the order of 1ºC. Bighead carps are found in large rivers, smaller rivers and streams, as well as lakes and ponds. Bighead carp can spawn in moving water.

The silver carp is uniform in color whereas the bighead has irregular dark blotches on its back and sides. The silver carp has a sharply keeled belly from the anal fin to the throat, whereas the bighead carp has a keeled belly from approximately its pelvic fins to the anal fin.
Thynnichthys sandkhol (Sykes, 1839) [Common Name:  Sandkhol Carp (English), Banga (Kannada), Sandkhol (Marathi)]
Thynnichthys sandkhol is a medium carp and resembles silver carp. It is a column-cum-surface feeder and is planktophagus. They have a nearly cylindrical body, dorsal fin of 12 rays, pectoral of 14 and ventral of 10 rays, gibbous head, eyes with whitish narrow irides. The dorsal in this fish is situated a little before the centre of the back. The fish attains sexual maturity in first year at 30cm in length and 500g in weight. It is a monsoon breeder and breeds only once a year. The fecundity of the fish is about 125,000/kg body weight. The fish grows very fast and it can grow to 0.9-1.4 kg in 9-12 months.

Sandkhol Carps are found in rivers and feeds on algae, protozoans, rotifers and crustaceans. They do not breed in ponds. They are cultivated in ponds in South India.