Study on length frequency and catch per unit effort of sturgeon spawners in the fishing grounds of Mazandaran province

 In this study, the catch composition and the catch per unit effort (CPUE) of sturgeon spawners caught by the gill net were investigated in the fishing grounds of Mazandaran province in two regions 3 and. Sampling and data collection of sturgeon spawning fish was done seasonally from 7 fishing grounds using gill nets with a mesh size of 150 mm. The results of the Chi-square test showed that there was a significant relationship between the time and place of Caught Persian sturgeon and Starry sturgeon (P<0.05) There was a significant relationship between the time and place of fishing with the abundance of fish spawners caught between regions 3 and 5 with spring and autumn seasons (P<0.05). There was a significant relationship between the time and place of fishing with the abundance of Starry sturgeon spawners caught between regions 3 and 5 only in the winter season (P<0.05). Also, a significant difference was observed between the amount of catch per unit effort of the spawning fishes caught in regions 3 and 5 (P<0.05) and between the averages of the catch per unit effort of the spawning fishes caught in the spring and summer seasons. Also, there was a significant difference between autumn and winter (P<0.05). Since the spawners of the caught sturgeon belonging to the Starry sturgeon and Persian sturgeon had the highest number compared to other species, so the results show the influence of the spatio-temporal factors of the habitats on their spawners.