Evaluation and comparison of percent change in species composition and Sturgeon CPUE in 2011and 2012 South coast Caspian Sea, province of Golestan

The marine survey for sturgeon stock assessment was conducted to estimate the abundance of each species, total abundance and their percentage composition.In this study, a sample of 5 stations from the four fishing Golestan province which since 1380, the Iranian Fisheries as fisheries was done selected. Sampling was carried out using the gillnet. The sampling in 2011, 247 specimens including 105 A. persicus specimens, 14 A. guldenstaedti, 44 A. stellatus, 71 Huso huso and 13 A. nudiventris were caught. In 2012, of 281 specimens, 143 A. persicus, 8 A. guldenstaedti, 19 A. stellatus,19 Huso huso and 52 A. nudiventris were caught. Species composition in 2011, including 42 percent of A. persicus, 6 percent of A. guldenstaedti, 18 percent A. stellatus, 29 percent Huso huso and 5 percent A. nudiventris. In 2012, Species composition, including 59 percent of A. persicus, 3 percent A. guldenstaedti, 8 percent, A. stellatus, 22 percent Huso huso and 8 percent was A. nudiventris. The average length of A. persicus in 2011, 162.62±19.8 cm, A. guldenstaedti 149.45±16.26 cm, A. stellatus 126.4±17.42 cm, Huso huso 167.69±60.72 cm and A. nudiventris 139.06±12 cm. In 2012, the average length of A. persicus and A. guldenstaedti to the 144.55±42.12 and 145.8±13.92 cm. The average weight of A. persicus in 2011, 22.38±8.57 gr, A. guldenstaedti 19.24±6.55 gr and A. stellatus 8.70±2.76 gr. In 2012, the average weight of A. persicus 18.66±11.43 gr and A. guldenstaedti 20±7.08 gr. The catch per unit effort (CPUE) in 2011 sampeling, equivalent to 5.23 and sampling in 2013 was equivalent to the 5.73.