Diversity of selective and non-selective fishing gear and their impact on the White Nile River, Khartoum State, Sudan

Abstract

This survey was conducted in Al-Kalakla Fishery (KF) and Jabel Awlia Dam Fishery (JADF) in the White Nile River, Khartoum state to identify the selective and non-selective fishing gear. The results showed the selective fishing gear represented by gill-nets and seine nets (beach nets) in both fisheries with clear variation in use. In KF, fixed nets were dominant (56%) in fishing and followed by drift net (33%), while cast nets were absent in this fishery. In JADF, fixed nets were dominant (63%) in use and followed by cast nets (14%). The average net length was 150 m with width 1.5 m. Non-selective fishing gear was luring gear represented by long-lines (Sareema and Jago). Average length of long-lines was 200 m with 200 hooks in both KF and JADF. Results showed selective tendency of particular mesh sizes of gill-nets in both KF and JADF towards some fish species as: Nile Perch (Lates niloticus L. 1758), Bayad (Bagrus bayad, Forskal, 1775), Kabarous (Bagrus docmak, Forskal, 1775), and large sizes of Dabis (Labeo niloticus, Forskal, 1775) were caught by fixed nets. Bulti (Tilapias), small sizes of Dabis (Labeo niloticus) and Gargur (Synodontis schall, Bloch and Schneider, 1801) were caught mostly by drift nets around breeding grounds and cast nets. Kas (Hydrocynus forskalii, Cuvier 1819), Kawara (Alestes dentex L. 1758) and Shilba (Schilbe intermedius, Ruppel, 1832) were caught by seine nets. Key words: Fishing gear, gill nets, seine nets, cast nets, long-lines