New Delhi, Nov. 11 -- Environmentalists questioned the newly launched Yamuna cruise service on Tuesday, saying it was introduced without an ecological impact assessment or navigability studies in one of the river's last remaining relatively clean stretches.

Bhim Singh Rawat, a Yamuna activist and member of the South Asia Network on Dams, Rivers and People (SANDRP), said the government should have commissioned an ecological impact assessment and a topographical study before allowing motorised cruise operations.

"This clean part of the river sees migratory birds, and efforts should be made to cause minimal disturbance. A similar plan to run a water taxi in this stretch failed in the past, but no lessons have been learnt. They should first...