"This result is a remarkable success for Black Sea dolphins. The international community has taken one step toward helping the species," Nike Entrup of the Whale and Dolphin Conservation Society told Reuters.

Environmentalists say a growing trade in the Black Sea dolphins over the past decade, especially by Russia, threatens their survival. The animals' vulnerability is increased by their slow reproductive cycle and water pollution, they say.

Georgia, one of six nations with a Black Sea coastline, had sought an outright ban on trade in the dolphins but that bid was defeated at the convention last week.

It later asked that the species be placed on a list that restricts trade through annual quotas. In this case, the quota is zero.

The move means Russia and other Black Sea dolphin exporters are prohibited from issuing export permits for commercial trade in the species.

Russia, the top exporter, is against increased protection for the dolphins, saying its trade does not pose a real threat to them. Trade had already been curtailed under the convention since 1979.

Bottlenose dolphins are popular at amusement parks and circuses because they are intelligent and easy to train. They are also sometimes used in human therapy programs.

About 120 live Black Sea bottlenose dolphins were traded internationally - at about $20,000 each and sometimes through the Internet - between 1990 and 2001, conservationists say.