Demographics of great sturgeon (Huso huso) in Iranian waters of the Caspian Sea (2008–2010)

Demographic data of the great sturgeon, Huso huso, from the Iranian coastal waters of the Caspian Sea were derived from measurements of individuals with a fork length ranging from 84 to 255 cm, obtained from commercial fisheries. The maximum age of fish caught in the south Caspian Sea was 30 years. The estimates of the asymptotic length L_∞ and the growth coefficient (K) were 265.255 cm and 0.062 per year for males and 275.78 cm and 0.08 per year for females, respectively. Total mortality rates obtained by Gulland's method were larger for males (0.64) than for females (0.46). Annual mortality rates were calculated as 47% for males and 37% for females. Data obtained in this study and their comparison with data from previous studies indicate that the great sturgeon stock is definitely exploited in an unsustainable manner.