The move closes a loophole that allows fraudulent traders to declare their caviar was caught the previous year and so avoid quota limits. Willem Wijnstekers, secretary-general of CITES, says the new measures suggest the convention can help to restore overfished commercial fish stocks to sustainable levels.

Another marine species, the rare Irrawaddy dolphin of Southeast Asia, was transferred from Appendix II to Appendix I. This forbids all commercial trade.

Minke Whales

Meanwhile, Japan's bid to ease controls on protection of the minke whale, by "downlisting" the species to Appendix II, which would allow trade in its meat to resume, was rejected by the conference.

The minke whale was hunted almost to extinction during the last century, but since it became a protected species, numbers are thought to have recovered to around one million.

Besides marine animals, commercially prized trees, particularly those with medicinal properties, emerged from the summit with enhanced conservation status.

Members voted to regulate global trade in agarwood, a resin found in two types of evergreen tropical trees.

The resin, produced by the trees in response to a fungal infection, is traditionally used in Asia to combat disease and in religious ceremonies. It's also used to make expensive perfumes.

Conservationists say illegal harvesting in countries including Cambodia, Indonesia, Malaysia, and Thailand is subjecting agarwood-producing trees to unsustainable pressures.

Yew Tree

Protection has also been tightened for the Asian yew, the main source of the anticancer drug paclitaxel, sold under the brand name Taxol.

Similarly, trade restrictions now apply to hoodia, a cactus native to southern Africa. Africa's Bushman people traditionally use the plant to suppress their appetite during long treks and there are fears it could be wiped out in the search for new anti-obesity drugs.

Ramin, a tropical hardwood tree, has been added to Appendix II. The tree, found in Indonesia, Malaysia, and the Philippines, has become the target of illegal logging. Resulting rain forest loss is seen as a significant threat to the orangutan in Indonesian Borneo.

"This decision should help block the flow of money to the pockets of the illegal timber mafia," said a spokesman for Telapak, an environmental nonprofit group based in Bogor, Indonesia. "We urge the CITES parties to take all necessary measures to enforce the new controls."

Elephants and Rhinos

By contrast, there has been a slight relaxation of CITES restrictions for two higher profile species of conservation concern. While a request from Namibia to be allowed to sell elephant ivory internationally was blocked, Namibian tribes are now permitted to trade locally in carved ivory trinkets.

Namibia, South Africa, and Swaziland, where black rhinoceros numbers have increased, also won a partial lifting of the ban on hunting the rhinos. Each country can export five black rhino trophies, though cash raised must be plowed back into conservation programs.

Overall the CITES conference sought to balance local economic realities with the need for more effective protection of endangered species.

"The Bangkok conference has crafted solutions to meet the particular needs of many wildlife species that are either endangered or that could become so if traded unsustainably," Secretary-General Wijnstekers said.

"These solutions seek to conserve the Earth's rich heritage of biological diversity while supporting the sustainable development of local communities and national economies."

Don't Miss a Discovery
Sign up for the free Inside National Geographic newsletter. Every two weeks we'll send you our top news stories by e-mail.

For more endangered-species stories, scroll to bottom.

LATEST NEWS VIDEOS Stuck Mars Rover About to Die? Giant Salamanders Helped to Spawn Rare Gorillas Spied Feasting on Figs More Videos in the News

SOURCES AND RELATED WEB SITES Convention on International Trade in Endangered Species (CITES) Telapak WWF Wildlife Conservation Society