Estimation of fish composition and catchability coefficient of gillnet in the Shadegan Wetland

To estimate the fish composition and catchability coefficient of gillnet, a survey was carried out during April 2011 to March 2012 in the Shadegan Wetland, Khuzestan Province, Iran. Samples were collected from five stations viz., Mahshar, Rogbe, Khorosy, ‍Salmane and Atish. Approximately 4300 fish specimens were measured and depletion method was used for the estimation of Catchability coefficients of gillnet. Mean±SD q value for Leslie model in different season was 0.008±0.006 and its maximum and minimum values were 0.001 (summer) and 0.004 (spring), respectively. Mean±SD q value for Delury model in different seasons was 0.0007±0.0001 and its maximum and minimum values were 0.002 (summer) and 0.0007 (winter), respectively. Mean±SD of q value for Leslie model in different stations was 0.008±0.006 and for Delury model in different station was 0.003±0.001. Mean catchability value of Leslie model was higher than that for Delury model. Using Students t-test, no significant differences between the calculated Leslie and Delury models among the different stations (P>0.05) and different seasons were observed (P>0.05). A comparison of catchability values showed that there are no significant differences among different seasons (ANOVA, F=0.32, P>0.05) and among different stations (ANOVA, F=0.29, P>0.05).