Amid growing alarm over accelerating extinctions, a major international conference opened in Geneva Saturday aiming to tighten rules on trade in elephant ivory and other endangered animal and plant species.

Thousands of conservationists and policymakers from more than 180 countries will meet for 12 days to evaluate regulations and species protection listings under the Convention on International Trade in Endangered Species (CITES).

"Business as usual is no longer an option," CITES Secretary General Ivonne Higuero said at the start of the meeting, warning that "nature's dangerous decline is unprecedented."

The treaty, created more than four decades ago, regulates trade in over 35,000 species of plants and animals and contains mechanisms to help crack down on illegal trade and sanction countries that break the rules.

The meeting follows warnings about rapid species decline, with a UN report in May indicating that one million species are being pushed to the brink of extinction.

"My fear is that we are... now really on the edge," Higuero told AFP ahead of the conference, saying she hoped the delegates in Geneva would "make what we call transformative change."

Inger Anderson, who heads the United Nations Environment Programme, echoed her sense of urgency, warning the conference that "we are losing species at a rate never seen before."

Poaching, illegal trade

But she voiced confidence in the effectiveness of the CITES treaty in protecting vulnerable species by ensuring all trade in them is sustainable.

"We need to find a workable balance between people and nature," she said.

The devastation caused to many species by poaching and booming illegal wildlife trade will be in the spotlight during the meeting, as will new challenges arising from illicit commerce increasingly moving online.

The plight of African elephants is expected to dominate the discussions.

Some countries are calling for stronger protections for all African elephants, while countries in southern Africa, where populations are better protected and healthier, are requesting resumption of ivory stockpile sales.

One of 56 proposals on the meeting's agenda aims to prevent traffickers from passing off illegal elephant ivory as coming from mammoths, by listing the long-extinct mammals as a threatened species and thus subject to regulated trade.

Southern white rhinos, the American crocodile and a range of shark and ray species are also on the agenda, as is the African giraffe, amid warnings that the gentle giant is facing a "silent extinction."

"The future of biodiversity is at stake but ... we have a unique opportunity to change the course," Andersen said.