A catastrophic fall in wild sturgeon numbers even as more and more of its lucrative caviar is farmed has stoked a bitter row over the best means of conservation - managed catch or outright ban.
No one disputes the sturgeon is in big trouble.
In a report issued on the sidelines of a UN wildlife conference in the Qatari capital Doha, the International Union for Conservation of Nature warned the sturgeon is now the single most endangered group of animals on its Red List of Threatened Species.
"Eighty-five percent of sturgeon, one of the oldest families of fishes in existence, valued around the world for their precious roe, are at risk of extinction," the report said.
"Four species are now possibly extinct," it added.
But there the consensus ends.
Some conservationists want to see a prolonged trade ban under Appendix I of the Convention on International Trade in Endangered Species (CITES) to allow the wild sturgeon stocks to recover.
"An Appendix I listing of highly endangered sturgeons, such as beluga, would ban the global trade of sturgeon products for an extended period of time," said Professor Ellen K. Pikitch, executive director of the Institute for Ocean Conservation Science at Stony Brook University in New York.
"An Appendix I listing would greatly reduce the illegal capture and trade of sturgeon, it would make monitoring and enforcement much simpler and much more effective," said Pikitch.
"At present, it can be very difficult for enforcement officers to determine if a particular shipment is legal or not.
"An Appendix I listing would also give sturgeon the long-term protection they require in order to recover. Given the great longevity and late maturity of sturgeons, recovery would take decades under the best of circumstances.
"It has been disappointing that CITES failed to use its authority over these past 12 years," she said.
But CITES itself and industry experts disagree, arguing the best way of conserving the remaining wild stocks is through careful management that gives local populations on the shores of the Caspian Sea and the great Russian rivers that are its homeland an interest in its protection.
CITES secretariat spokesman Juan Carlos Vasquez said counterintuitively the growing share of farmed sturgeon in the profitable caviar market was damaging the protection of wild stocks.
"Many countries are farming and this is not necessarily good for sturgeon in the wild, because they withdraw the value of the fish in the Caspian and there is no incentive for the countries to do more research control and protection," he said.
"It won't help," he added, referring to calls for an Appendix I listing.
"CITES' job is not to have tigers in zoos and sturgeons in farms. Our job is to keep the species healthy in the wild, and it's not always by banning trade that you will achieve this objective.
"If you ban for ever, they accommodate to the ban and create illegal trade and the countries disengage."
French Armenian Armen Petrossian, whose caviar house accounts for between 10 and 15 percent of the world market and who heads the International Caviar Importers Association, agrees.
He says his business now relies 100 percent on farmed sturgeon as its output has risen from just 500 kilogrammes (1,100 pounds) of caviar in 1998 to between 150 and 160 tonnes now.
During the same period the volume of legally produced wild caviar has fallen from as much as 180 tonnes to practically nothing as zero quotas have been imposed in many areas.
"Technically, we could completely dispense with wild caviar, but it would be a terrible mistake. The malign effect of farming has been to remove any incentive for managing the Caspian," Petrossian said.
"CITES would have done better to preserve an area of controlled exploitation to remove the pretext for a black market and provide a livelihood for local fishermen who currently have no alternative to the black market."