SOME BIOLOGICAL ASPECTS AND CATCH TREND OF MULLETS IN THE SOUTHERN CASPIAN SEA

Mullet and other bony fishes are caught by beach seine in Iranian coastal zone in Golestan, Mazandaran and Guilan provinces. The catch and CPUE trend of mullets were compared during 1993 to 2001 and some biological characteristics such as: species composition, length, weight, K and age of Liza aurata and L. saliens were analyzed. In 1990s, the results showed that amount of catch has been increased and the maximum catch occured in 2001. CPUE decreased from 114 kg (in each seine) in 1993 to 43 kg in 1996 whereas 2001 increased to 66.4 and 78.4 kg in 2000 and 2001, respectively. The mean fork length, weight and K for L. aurata species were measured 32.7 and 32.3 cm, 418.3 and 419.8 g and 0.61 and 0.93 and for L. saliens species were 27.5 and 25.1 cm, 224.7 and 179.1 g and 0.91 and 0.71 for years 2000 and 2001, respectively. According to this data in spite of increasing in catch, CPUE of L. aurata has increased and there is no changes in respect of biological aspect. Therefore, it was concluded that this species is harvested of a sustainable level.