The weight and production of fish in the famous Kulekhani Reservoir (Indrasarobar) in Makawanpur has been declining in recent years. According to the Kulekhani Fisheries Development Center and the Indrasarobar Fishermen's Association, chemical pesticides used in commercial vegetable farming in villages around the lake are the main reason for the decline in fish growth.

Indrasarovar, which is about seven kilometers long and covers an area of ​​11,156 cubic meters, is currently producing fish at a rate of 4.5 kg per cubic meter by placing 400 cages, said Bikash Balami, vice president of the Indrasarovar Fishermen's Association. The association has stated that both the average weight and number of fish have been decreasing in recent years.

According to Balami, pesticides and chemical fertilizers used in vegetable farming enter the lake through rivers and canals during the rainy season. He said, "When this pesticide-contaminated water reaches the lake, it affects the natural food of the fish (microorganisms that fish eat, called plankton) and microorganisms, due to which the fish do not grow as fast as before."

Cold water fish species such as silver carp, bighead and grass carp are particularly affected. These fish rely on naturally occurring green algae and small animals. Balami, vice-president of the Fishermen's Association, mentioned that the fish's weight and growth have decreased as pesticides destroy these resources. 

According to him, the association has currently made 650 families share members and arranged for fish production, sale and dividend distribution. This income has been used to support everything from school operations to community infrastructure maintenance. 

According to fish entrepreneur and hotel operator Purna Thapa Magar, the ecological balance of the lake is deteriorating due to the effects of pesticides. He said, "The fish that used to grow up to two kilos are now difficult to reach even one and a half kilos. Their growth capacity is also decreasing due to the decrease in the natural food of the fish." He said that fish from Kulekhani Lake is considered special among the dishes served in his hotel. 

Local communities in the villages around the lake have made fish farming their main source of income. The income from fish sales has been contributing greatly to the operation of the village school, road maintenance and community development. Magar said that farmers are now facing financial losses due to the decrease in the size of the fish. 

According to Yuva Sansar Balami of Kulekhani-Kalanki, the work of putting fish in the lake, taking care of it and selling and distributing it is done by the Indrasarobar Fishermen's Association. He said, "The lake has provided employment to hundreds of households in the village, but as the fish have become smaller, the income has decreased, which has also affected the village's economy." He said that tourism has been promoted due to the lake and fish.

Government agency's perspective

Acting head of the Fisheries Development Center Kulekhani, Manita Poudel, said that the weight loss of fish due to pesticides is a serious issue and informed that a scientific study has been started on it. "Recent tests have found that the amount of chemical components in the water is higher than normal, so it may have affected the growth rate of the fish," she said. 

According to Acting Chief Poudel, the center is currently producing and selling silver carp, bighead, common carp, grass carp, rahu, naini, bhakur, tilapia, sahar and katle fish. 

She informed that about two lakh fry are released into the lake in the third week of Bhadra every year. According to her, since Kulekhani fish is mostly consumed locally, the cleanliness of the lake water is essential to maintain its quality. Therefore, the center has been conducting training in schools and communities on reservoir conservation and healthy fisheries.

Pesticides and environmental impact

Commercial vegetable farming is spreading rapidly in Thaha Municipality and Indrasarobar Rural Municipality of Makawanpur. Farmers use pesticides like carbofuran, malathion, dichlorophos to increase production, which have long-term effects on water and soil. 

Saroj Yadav, head of the Natural Reservoir Fisheries Promotion and Conservation Center, Hetauda, ​​informed that the production and weight have decreased because pesticides damage the natural food and body of the fish. ‘Pesticides change the chemical composition of water, the rate of fish eggs hatching decreases, and the intestines and gills are damaged,’ he said, ‘If water mixed with pesticides is coming, it is necessary to control it, otherwise not only the biodiversity of Kulekhani Lake, but also the local drinking water and tourism economy may be affected.’