Investigation of correlation of some environmental factors on survival of Ruitilus frisii kutum fingerlings (Case study; Iranian coastal water of the Caspian Sea)

Most valuable fishery species such as Ruitilus frisii kutum that is the most important bony fishes of the Caspian Sea is anadromous and migrate into rivers for spawning. So characteristics of estuaries as spawning sites of fishes have an important role in their survival. Studies showed that in the past most of Iranian coastal rivers of the Caspian Sea, were the normal breeding sites of kutum. But now, just some of them are considered as Main site of spring migration of kutum. Therefore, we studied the effect of environmental factors in the main estuaries of southern coast of the Caspian Sea and its impacts on fish stock recruitment of kutum fingerlings in a Twenty-year period from 1992-2012. First data of physicochemical factors related to the amount of ten estuaries in four months of releasing time of kutum and amount of survival of two years old fingerlings as a index of stock recruitment were obtained and examined in SPSS. Results showed that is no significant relationships among the changes of factors and recruitment of kutum during of period of study on recruitment of kutum.