Investigation of the effect of environmental factors on white ()fishing in the middle center of the Caspian sea from Chapakrod to Mirrod

The aim of this study was to investigate the important biological characteristics. Including: age and growth of whitefish and environmental factors such as water temperature for wind, study of litter, catch rate of these valuable fish. This study was recorded and biometric in 4 whitefish stations and the length of the fork and its weight were recorded. In each station, the specific bed material, temperature, water and wind direction were recorded. And statistical analysis was performed. 72 fish (40%) are male and 108 fish (60%) are female. Therefore, most whitefish studied are females. 1 fish (0.6%) is 1 year old, 20 fish (11.1%) are 2 years old, 119 fish (66.1%) are 3 years old and 40 fish (22.2%) are 4 years old. Therefore, most of the whitefish studied are 3 years old. Most of the whitefish studied are between 28 and 34 cm. Also, most of the white fish studied are between 701 and 1000 grams. The results showed. In general, the highest weight of fish in December is in Cleaver station. Therefore, with 95% confidence, it can be claimed that environmental factors affect the weight and length of whitefish caught in the central region of the southern Caspian Basin from the distance of Chapkrud to Mirrood.