Lack of proper guidelines has led to unplanned construction of structures in tourist sites and thoughtless commercial tourism, causing massive damages to ecosystem and natural habitat of wildlife and marine life in forests, sea and plain as well as on hills, conservationists warn. Tourism business has proliferated in recent years taking a growing number of travellers from home and abroad to major tourist attractions and exploring new spots, but operators care little about protecting the ecosystem of particular sites, they point out. While travellers often lack environmental awareness, little or no enforcement of relevant laws also contributes to the silent ecological disasters in the sites of historical importance and outstanding scenic beauty, they say. For a sustainable tourism development, green campaigners stress the need for formulation of comprehensive ecotourism guidelines, effective coordination among related agencies and massive awareness building campaigns to protect the ecology and natural habitats of flora and fauna. Usually local tourists, often unaware of environmental issues, flock the natural sites and litter the places with garbage, fast-food packets, empty cans and bottles. Some of them travel in big groups and use loudspeakers, breaking the peace and tranquillity of nature and disturbing the wildlife. Popular tourism spots like Cox's Bazar and St Martin's Island as well as different national parks and reserve forests are losing their particular ecosystem for reckless tourism these days. The term ecotourism was coined in 1983 and initially used to describe nature-based travel to relatively undisturbed areas mainly for educational purposes. The concept has now developed into a scientific approach to the planning, management and development of sustainable tourism products and activities. Conservationists stress that the country needs to switch over to ecotourism if it is to sustain tourism growth and protect the nature. Anwarul Islam, professor of zoology at Dhaka University and chief executive of the Wildlife Trust of Bangladesh, has said the country boasts a number of treasures of nature