A team of U. S. and Kazakh scientists have said that conservation strategies for beluga sturgeon should focus on reducing the overfishing of adults.

Scientists from Kazakhstan and New York's Stony Brook University said in a recent issue of the journal Conservation Biology that harvest rates today in the Caspian Sea are four to five times too high to sustain a healthy population of the caviar-producing sturgeon.

Phaedra Doukakis, the study's lead author, said that they studied sturgeon in the Ural River, the only remaining Caspian Sea river where beluga sturgeon reproduce unhindered by dams.

On the brink of extinction in the Azov Sea, Beluga sturgeon are already extinct in the Adriatic Sea. The fish can live to be more than 100 years old and do not reach maturity until 9 to 20 years of age.

The scientists further said that population productivity can be increased tenfold by capturing sturgeon no younger than 31 years of age because it would allow a longer period of breeding and survival for adult females. (With Input From Agencies)