Study of trend process of ( Rutilus frisii kutum ), ( Liza spp.) and ( Cyprinus carpio ) in provinces of Golestan, Mazandaran and Guilan (2009 – 2011)

The Caspian Sea is the largest lake in the world, depending on which is very important. Bony fishes of the Caspian Sea, which are among the most important and most valuable fish stocks. Unfortunately, it has been declining in recent years for several reasons. In this study, bone fishing conditions in fishing cooperatives on the southern shores of the Caspian Sea (Provinces: Golestan, Mazandaran and Guilan ) 2009 to 2011 years experience in fishing seasons were analyzed. Results showed that from 2009 to 2011 bony fish catches have declined. The highest decrease in the amount of fishing to catch of kutum with 22.5 % and the highest rate of decline in percen of fishing carp fishing with 67 % of the species are. And the only species that has increased the catch of mullet is about 33.9 % of the catch has increased. The catch per unit of fishing effort (CPUE) in 2011 is compared to 2009 represents approximately 9.7 % for bony fish increased from about 197 kg to about 216 kg is reached. The catch per unit of fishing effort were marked with the mullet fish increased only about 63.9 has had the kutum and carp and other fish species in the 5.2 and 60 and 6.9 percentage has decreased. Generally, Caspian Sea Bony fish have large fluctuation over the past decades and the current figures, the total can be inferred that the uncontrolled exploitation of these stocks have been fished so the pressure on some species (such as carp in Golestan province), resulting in a severe reduction in the population of the Iranian coast of the Caspian Sea is that fisheries management and recommended a comprehensive program to prevent the extinction of this species.