Sturgeon Swimming Towards 'Extinction Vortex'
July 14, 2008 - NewScientist.com news service
By Peter Aldhous
Irrational preferences for rare products are likely to drive the few remaining caviar sturgeon in the Caspian Sea to extinction, warn biologists in France. They have shown that snobbish attitudes drive a strong preference for caviar supposedly from "rare" species, even when the samples are the same.
Franck Courchamp and Agnès Gault of the University of Paris-South in Orsay ran taste tests at luxury receptions, where people were used to eating caviar, and among more naïve consumers at supermarkets.
The consumers were presented with samples said to be from a "rare" and a "common" species – although both actually consisted of eggs from farmed sturgeon.
Even before tasting, 57% of people at the luxury receptions expressed a preference for the "rare" caviar, while none preferred the "common" alternative, Courchamp told a meeting of the Society for Conservation Biology in Chattanooga, Tennessee, on 14 July.
After they had tasted the two identical samples, 70% of the experienced consumers said the preferred the "rare" sample.
It was the same story in the supermarkets, with 52% preferring the "rare" caviar before tasting it, and 74% expressing the same preference after they had done so.
"It's very scary," says fisheries scientist Ellen Pikitch of the Pew Institute for Ocean Science in New York.
The fact that people who are not yet in the champagne-and-caviar set have the same predilection as established consumers means that threats to sturgeon will only grow with rising prosperity. "The expanding economy of China is going to put hundreds of thousands of people in reach of these kinds of luxury products," Courchamp notes.
He argues that similar preferences for the rare can drive an "extinction vortex" in many circumstances – for example, when trophy hunters selectively target endangered animals.
In the case of caviar, it means that the availability of farmed products may do little to protect sturgeon from extinction in the absence of a total ban on trading wild-caught caviar.
A one-year ban was introduced by the Convention on International Trade in Endangered Species (CITES) in 2006, but failed to halt the sturgeons' decline.
"You don't save species by stopping trade for a year," says Pikitch, who runs the charity Caviar Emptor, which is striving to save the Caspian Sea's sturgeon.
The next opportunity to achieve a longer-lasting ban will come in 2010, when CITES member nations will meet in Doha, Qatar. According to some estimates, sturgeon could be virtually wiped out in the Caspian Sea by 2012 at current rates of exploitation.