Effects of Seasonal Variation on Fish Catching in Jebel Aulia Reservoir on the White Nile, Sudan

摘要

This study was conducted to see the effects of seasons on fish production, in Jebel aulia dam south of Khartoum45 km during the period January to December 2014, (containing 12 months) includes three seasons, summer,autumn and winter. 23 species belonging to 14 families were recorded during the period of investigation. Distributionproduction of fish in seasons as follow: in summer the high production is Tilapia in March 61.2%, April 53.3%, May40%, finally June 32%. Bagrus bayad in March 9.9%, April 5.6%, May 12.6%, finally 4.9% in June. The fish which israre is Disticodus niloticus and Citharinus citharus. High production months in the summer are June 36%, April 23%,March 21% and May 21%. In autumn the fish species which very high production is tilapia in July 25.9%, August31.6%, September 33.5% and October 9.9% followed by Schall fish and Labeo niloticus. In winter the study foundthe high production of species is Tilapia, labeo niloticus and Hydrocon Forskalli. The months which is highproduction in winter containing November, December, February and January. The study showed that the fishproduction seasons are summer 37.15%, autumn 35.95% and finally winter 26.90%.