In this paper, effect of seasonal variations and colour monofilament gill nets for fishing were invesitigated. Nets used on experiments have 40 and 55 mm mesh size and were used gill nets with hanging ratio 0.50 and 0.67. Black, blue, green and bordeu coloured monofilament gill nets were used in experiments. A total of 1097 speciments including Capoeta trutta (Heckel,1843), Cyprinus carpio (Linaeus, 1758), Barbus rajonorum mystaceus (Heckel, 1843), Barbus esocinus and Barbus xanthopterus (Heckel, 1843) species were cought. By a survey of the temperature increase as a result, the fishes' activity in that rate percentage increase with Cyprinidae's general character in accordance and therefore, fall, winter and spring, the fish catch in the number of differences that were detected. According to the results in colour gill nets captured % 57.97 of all fish (636 units) in spring, 26.25 % in autumn, 15.77 % is catching in the winter have been determined.