With a budget of less than four million euros, the 175-member Cites is one of the poorest conventions under the UN umbrella.
Besides the hotly contested proposed tuna fishing ban, hotly contested by the sushi-loving Japanese and some fishermen, Cites will look at reopening trade in ivory, protecting several types of shark, and a total ban on international trade in polar bears.
About 120 of the 175 member states are set to gather for the 13-day conference.
The meeting seeks to strike a sustainable balance between protection and commercial exploitation for thousands of species.
Measures must receive a two-thirds majority of those nations present to be adopted, and are then enforced by laws passed in member nations.
The Cites hierarchy of protection
Species are listed on three levels, according to the degree of
protection they need:
Appendix I provides the highest amount of protection and covers about 530 animals, including tigers, great apes, snow leopards and sea turtles, as well as more than 300 plants. Bluefin Tuna is being proposed for inclusion at Doha.
Appendix II covers the vast majority of the 33,000 species protected by Cites. They are "not necessarily threatened with extinction" but exploited in an unsustainable manner.
Appendix III species are protected by national laws.