In Thailand, speakers at the opening of an international conference on endangered species appealed for measures to protect natural resources and stem illegal trade in endangered wildlife.

The delegates must decide to what extent animals such as the African elephant and the great white shark can be commercially exploited.

On Saturday, the annual meeting on the Convention on International Trade in Endangered Species of Wild Fauna and Flora - or CITES - opened in the Thai capital of Bangkok.

The delegates will debate more than 50 proposals during the 12-day gathering. Environmentalists are expected to push for stronger trade restrictions on many species, but some countries are likely to call for easing the rules.

At a news conference Saturday, Suwit Khunkitti, the Thai minister of natural resources and the environment, said animals and plants must be protected against unscrupulous traders.

"Traders see our natural resources in different ways - as a kind of exotic supermarket, and as a hub for bringing and sending on illegally caught wildlife from other countries," said Suwit Khunkitti. "If you can remove the demand, the trading will stop."

But the deputy director for the United Nations Environment Program, Shafqat Kakakhel, says the CITES convention is not only an important instrument for protecting endangered species, but also as key to promoting sustainable development.

"Without a robust system of biodiversity, humankind cannot achieve economic and social development," said Shafqat Kakakhel. "There are human lives behind the lives of animals and the species and the plants that we seek to protect."

Some delegates at the conference think the only way to save endangered animals and plants is to completely outlaw commercial exploitation. Others, however, argue that limited, sustainable trade allows for better programs to manage wildlife.

"The challenge, of course, is to ensure that the trade that occurs doesn't threaten the wild populations, or is conducted in a manner that enhances the economic benefits through sustainable development programs in the countries of our convention," said Jim Armstrong, deputy secretary general of CITES.

Southeast Asia is seen as a hub for the legal and illegal trade in animals and plants.