"Tourism has huge potential for good and evil," UN Environment Programme (UNEP) executive director Klaus Toepfer told reporters at the fifth World Parks Congress in the eastern harbour city of Durban.

"Tourism relies on stable and healthy communities and environments. It cannot ruin the very wildlife and landscapes the visitors pay to see and then move on," Toefper said.

UNEP and Conservation International released a report at the 10-day conference where thousands of delegates from across the globe are discussing the world's 100,000 protected areas and how to safeguard them.

The report said rapid tourism growth was occurring in countries known for their rich biodiversity.

These include Cambodia, Brazil, Dominican Republic, El Salvador, Laos, Nicaragua and South Africa. In all those countries, tourism more than doubled between 1990 and 2000.

"With nature and adventure travel one of the fastest-growing segments within the tourism industry, the Earth's most fragile, high biodiversity areas are where most of that expansion will take place," the report said.

"While tourism has the potential to provide opportunities for conserving nature, tourism development, when done improperly, can be a major threat to biodiversity."

Tourism generates 11 percent of global gross domestic product, employs 200 million people and transports nearly 700 million international travellers per year, a figure expected to double by 2020, the study showed.

The leading author of the report, Costas Christ, said a combined strategy linking tourism development, nature conservation and communities living in protected areas was the only way forward.

"We are at a crossroads in the Earth's last strongholds for biodiversity, where nature, struggling communities and the expanding world of tourism meet," he said.

"We can develop strategies that both conserve Earth's most endangered ecosystems and help make a significant contribution to alleviating proverty."

TERRA.WIRE