Age, growth and biomass of the golden gray mullet (Chelon aurata, Risso., 1810) in Iranian waters of the Caspian Sea

This research was carried out in order to determine the length and age composition, calculate growth and mortality parameters and calculate the biomass of golden gray mullet in the Iranian waters of the Caspian Sea during the year of 2022-2023. The biometric data were collected from beach seine fishing cooperatives in the Guilan, Mazandaran, and Golestan provinces. The mean (± SD) fork length and total weight were measured at 29.9±4.8 cm and 305.7±143.0 g, respectively. The age range was 2 to 11 years, and more than 74.4% of the age group were 3 to 4 years with the mean (± SD) fork length of 26.3±5.1 and 31.3±5.6 cm, respectively. In the relationship between fork length and total weight, the values of a and b were calculated as 0.018 and 2.836, respectively, with a correlation coefficient of 0.97. Growth parameters, including the von Bertalanffy growth equation constants (K, L∞, and t0), were determined as 0.14 (/year), 64.0 cm, and -1.02, respectively. Mortality parameters, encompassing total mortality (Z), natural mortality (M), and fishing mortality (F), were calculated as 0.95, 0.30, and 0.65, respectively. The biomass of golden gray mullet was determined 12155.5 tons. This research provides valuable information in the direction of sustainable management and protection of golden gray mullet stocks in the Iranian waters of the Caspian Sea.