Effect of Beach Seine Height and Mesh Size on Catch Characteristics in the Southern Part of the Caspian Sea

In this study, the influence of height and mesh size of beach seine net on the amount of fishing, length frequency and species composition of caught fish was examined. Two beach seine nets with 20 and 24 m heights and each net with 30 and 33 mm center part mesh size were used by two fishing cooperatives during 2008 and 2009. Rutilus frisii kutum and Mugil auratus were selected as a target fish in this study. Catch and biological data were measured and recorded. Results indicated that the height and mesh sizes used in the present study had significant effect on the catch characteristics in terms of amount of species, catch rates and species composition. Amount of catch was reduced in 24 m beach seine in comparison with 20 m height net both in 2008 and 2009. There were significant differences between fish caught by 30 and 33 mm mesh size net in 2008 and 2009. With an increase in size of mesh net from 30 to 33 mm, amount of R. frisii kutum catches increased but amount of M. auratus catches decreased. There was no any especial effect of height and mesh size on fish length. Amount of bycatch also increased in relation to net height from 20 to 24 m.