Sharath S. Srivatsa Craters on the banks of the Cauvery affect Deccan Mahseer's spawning area It is one of the largest freshwater game fish Construction boom in Bangalore blamed GALIBORE (Ramanagar dt): Past midnight, the chugging of tractors carrying men and shovels punctuates the tranquillity of the forest. In an hour or two, shadowy figures furtively fill the tractors with fresh sand, which are quickly then driven away from the scene, leaving behind deep craters on the banks of the Cauvery. The illegal extraction of sand from the river and its banks poses a grave danger to the Deccan Mahseers, one of the largest freshwater game fish in the world and categorised as endangered species. Referred to as the "Tiger of Water' for their fighting instincts, Mahseers are falling prey to the illegal sand mining along the Cauvery, especially the approximately 30-km stretch between Doddamakali in Karnataka and Hogenakkal in Tamil Nadu. Declining numbers "The craters caused due to illegal sand extraction are affecting the spawning area along the river course, leading to a decline in their number. Illegal miners operate even during the monsoon when the river is in spate, which also coincides with the breeding season of the Mahseers,' Lokesh Kumar, Resident Manager of Galibore Fishing Camp, managed by the Jungle Lodges and Resorts (JLR), told The Hindu. "Tractor loads of sand are extracted illegally in many places, including Shimsha, Ontigundu and Bommasandra. The activity continues unabated between 1 a.m. and 4 a.m. daily,' he added. The Deccan Mahseer lays eggs in shallow waters that have fine sand, which is also safe for its fingerlings. However, deep craters left behind by the illegal extraction may drastically change the course of the river and increase its depth destroying the spawning area. The fingerlings can also fall prey to bigger fish, leading to a decline in population. Making matters worse, conservationists say, is the fact that Mahseers are slow breeders. According to the Joint Secretary of Wildlife Association of South India (WASI) Prathap Ruthnaswamy, sand plays a crucial role in propagation of Mahseers and sand mining is leading to habitat loss. "In fact, due to mining, the number of mahseers caught by anglers and their sizes has come down drastically. Mining in the Arkavathi and the Shimsha riverbanks has also brought down the Mahseer population,' said Mr. Ruthnaswamy, who has been angling in the area for nearly two decades. He said: "The construction boom in Bangalore has fuelled the sand extraction here. '