Problem Threatens Stock of Sturgeon
Researchers have called into question the number of beluga sturgeon in the Caspian Sea. Some say the sturgeon, a 200-million-year-old species, is in serious trouble. But in September, the Geneva-based Convention on International Trade in Endangered Species of Wild Flora and Fauna, known as Cites, announced that numbers of beluga sturgeon rose to 11.6 million from 9.3 million from 2001 to 2002, 25 percent. The figures were supplied to Cites by Russia's Caspian Fisheries Research Institute in Astrakhan, once the country's caviar capital.
The Fish and Wildlife Service is considering these figures as it decides this month whether to impose an import ban. The numbers have been challenged by a number of marine scientists, in and out of Russia, and the controversy has focused attention on whether Cites can rely on data supplied by member countries that have an interest in overstating the population of the species.
Four American and Canadian fisheries specialists were asked to look at the Russian numbers and the studies they were based on. They found that the methods were flawed and that the study populations were too small.
"The catchabilities assumed for these sturgeons are crazy, much too low," said UBC fisheries professor Daniel Pauly. "I have worked extensively on trawl fisheries, and on this very issue of catchability, and have never encountered anyone using such low catchabilities for large benthic fishes."s