Sturgeon Stocks Are in Decline Around World, Survey Reports
By CORNELIA DEAN
Published: September 22, 2005
Sturgeon, the fish that produce black caviar, are severely depleted or threatened with extinction almost everywhere in the world, researchers are reporting today.
''I could not recommend that people eat caviar from any wild population of sturgeon,'' said Ellen K. Pikitch, director of the Pew Institute for Ocean Science at the University of Miami and the lead author of a comprehensive new study in today's issue of the journal Fish and Fisheries.
Experts have previously voiced alarm about the decline of sturgeon, but today's report is the first global assessment of their precarious state. Legal catches have plunged to about 15 percent of their peak 30 years ago, the researchers said, and aquaculture is now the leading legal source of caviar.
Since 1997, the fish have been covered by the Convention on International Trade in Endangered Species, but illegal trade continues. The fish are also imperiled by dam construction that has cut off spawning grounds and by damage to their habitats from pollution.
''Few viable sturgeon fisheries now remain,'' the researchers wrote.
Their report covered the 25 species of sturgeon and the 2 species of paddlefish, their near relatives, which also produce commercial roe. Sturgeon typically take 15 years to reach reproductive age and then typically spawn only every three or four years. As a result, they are particularly vulnerable to overfishing, and they are expensive and time-consuming to raise in captivity.
Sturgeon have been caught for caviar since 500 B.C., Dr. Pikitch said in an interview, and at one time the salty little eggs were so abundant they were served in bars ''like beer nuts.'' But in the last century or so, one sturgeon population after another in Europe, North America and Asia has been fished to the brink of extinction.
Though aquaculture may be the best hope for preserving sturgeon, the practice can cause its own problems through the removal of brood stock from the wild, introduction of disease from penned fish, their escape into native populations, and the requirement that other fish be caught to feed the captive fish.