Department of Fish Sciences, Neelain University, Khartoum, Sudan
Received date: April 06, 2017; Accepted date: May 19, 2017; Published date: May 26, 2017
Citation: Ahmed AMM (2017) Effects of Seasonal Variation on Fish Catching in Jebel Aulia Reservoir on the White Nile, Sudan. Fish Aqua J 8:202. doi: 10.4172/2150-3508.1000202
Copyright: © 2017 Ahmed AMM. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
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This study was conducted to see the effects of seasons on fish production, in Jebel aulia dam south of Khartoum 45 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. Distribution production of fish in seasons as follow: in summer the high production is Tilapia in March 61.2%, April 53.3%, May 40%, finally June 32%. Bagrus bayad in March 9.9%, April 5.6%, May 12.6%, finally 4.9% in June. The fish which is rare 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%, August 31.6%, September 33.5% and October 9.9% followed by Schall fish and Labeo niloticus. In winter the study found the high production of species is Tilapia, labeo niloticus and Hydrocon Forskalli. The months which is high production in winter containing November, December, February and January. The study showed that the fish production seasons are summer 37.15%, autumn 35.95% and finally winter 26.90%.
Jebel Aulia Dam; Reservoir; Seasons; Fish species; Investigation production; Variation
Jebel Aulia Dam was constructed in 1937 across the White Nile some 45 kilometres south of Khartoum. It resulted in the formation of larger shallow lake and covered estimated area of about 12,000 hectares. The Dam stores about 3.5 Millard cubic meters of water. Maximum depth of the reservoir is about 15 meters during the time of high flood (late August to mid-September) while a minimum depth of 5 meters is attained in May, when the reservoir is nearly emptied to a normal river level. Fish and fisheries of White Nile have been investigated by several workers. The taxonomy and characteristic of fish were compiled by Boulenger  in his treaties or fish fauna of the Nile. Girgis  recorded 18 families and 62 species from the swamps and the southern tributaries of the White Nile. The feeding and breeding habits of some common Nile fish were studied by Pekkola  and his investigations were further extended by Sandon . Sandon  investigated the fishes of northern Bahr Elgazal and stated that fishing follows the seasonal regime of flooding and fallowing water. One hundred and eight species were recorded by Sandon  from the Sudan waters of the White Nile system. They belonged to 51 genera and 23 families. More recently  reported that the fish fauna of the Nile basin is rich and diversified and includes at least 54 genera and well over 300 species. Gidiri  carried out a detailed study on the biology of genus Synodontis at Khartoum which its establishment of Synodontis khartoumensis as a new species. The present paper however is an attempt to consider the distribution and abundance of fish of the White Nile in the area affected by Jebel Aulia Dam.
The area investigated was Jebel Aulia Dam two sets of gill nets were used to catch the fish the first set with mesh size ranging between 40 mm-120 mm and 1.5 meters-2 meters in depth. The second set of gill nets had a mesh size ranging from 70 mm-90 mm and 1.55 meters-1.80 meters in depth. Gill nets were set overnight. The catch was sorted out immediately after collection and fish identified down to species level. Total weight of fish was recorded in kilogram (kg). The period of study was (January-December 2014).
Fish population in the study area obtained 23 species belonging to 14 families were recorded during the period of investigation. These are listed as follows in Table 1. In summer Tilapia fish , and Bagrus bayad is high production in month March, April, May and June. The rare fish were Disticodus niloticus and Citharinus citharus in Table 2. High production of months in summer is June 36% (Table 3).
|Family (14)||Species (23)|
|(1) Mormyridae||1-Mormyrus caschive|
|(2) Mochokidae||1-Synodontis schall|
|(3) Bagridae||1-Bagrus bayad|
|(4) characidae||1-Alestes dentex|
|(5) Citharinidae||1-Disticodus niloticus|
|(6) Schilbeidae||1-Schilbe mystus|
|(7) Cyprinidae||1-labeo niloticus|
|(8) Cichlidae||1-Oreochromis niloticus|
|(9) Clariidae||1-Clarias lazera|
|(10) Protopteridae||1-Protopterus aethiopicus|
|(11) Centropomidae||1-Lates niloticus|
|(12) Tetraodontidae||1-Tetraodon lineatus|
|(13)Malapteroidae Malapteroidae||1-Malapterurus electricus|
|(14) Osteoglossidae||1-Heterotis niloticus|
Table 1: Showed the families and species of the study.
Table 2: showed fish production in months of summer 2014.
|Months of summer||Production(kg)||%Percentage|
Table 3: showed months of summer and production (kg).
In autumn also tilapia and Labeo niloticus is high production (Table 4). Months of autumn which is high are July, October, August and September, in Winter also Tilapia, Labeo niloticus and Hydrocon Forskalli is high production but the fish was very rarely is Bynii, Citharus, Disticodus and Labeo horii (Tables 5 and 6).
Table 4: Showed the fish production in months of autumn 2014.
|Months of autumn||Production(kg)||%Percentage|
Table 5: Showed months of autumn and production kg.
Table 6: Showed fish production in months of winter 2014.
High months in production in winter is November, December and February the study show the high season in production is summer 37.15%, autumn 35.95% and winter 26.90% (Tables 7 and 8). The boats were made of woods, metal, and fiberglass. Gill net and cast net are very famous nets in the Reservoirs. The boats made of locally woods (Table 9).
|Months of winter||Production (kg)||%Percentage|
Table 7: Showed months of winter and production kg.
Table 8: show seasons variation and fish production 2014.
|Boat kinds||Nets kinds||Woods kinds|
|Wood boat||Gill net||haraz|
|Metal boat||Cast net||sonut|
Table 9: show the boat, net and kind of wood in fish catching.
The study showed that high production was recorded in summer season 37.145%, autumn 35.95% and finally winter 26.95%. 23 species and 14 families were found in the study. The important species in this study were Oreochromis niloticus, Labeo niloticus and Synodontis schall. The rare fish in the dam were Disticodus niloticus, Labeo niloticus and Citharinus citharus. The present study agrees  had found 14 families and 21 species. The study agrees  that the boats in Jebel aulia were made from woods, metal, shroug and fiberglass. Otherwise the local names of the nets were gill nets and caste net. The kinds of wood by local name are Haraz, Sonut, Neem and Sayal.
Girgis  recorded 18 families and 62 species from the swamps and the southern tributaries of the White Nile but in this study found 14 families only. 108 species were recorded by Sandon  from the Sudan waters of the White Nile system. They belonged to 51 genera and 23 families but in this study 14 families may be return to periods between the two studies. More recently  reported that the fish fauna of the Nile basin is rich and diversified and includes at least 54 genera and well over 300 species .
1967 studied all fishes in Sudan but this study is included only Jebel aulia dam (Figure 1).
We express deep sense of gratitude to the head of department of fish sciences, the technical support of Mr. Elnuman Babikir.