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1 SPECIES DIVERSITY AND ABUNDANCE OF FISH IN ROSEIRESRESERVOIR, BLUE NILE STATE OF SUDAN 1 EGBAL O. AHMED, 2 MOHAMMED E. ALI, 3 AFRA A. AZIZ, 4 AHMED M. MUSA 1,3,4 Department of Fish Science, Faculty of Agricultural Technology and FishScience, University of Elneelain, Khartoum, Sudan. P.O. Box: 12702, Postal code. 2 Fisheries Research Centre ( ALShagara ) Khartoum, P. O. Box egbalosman1@gmail.com Abstract - Freshwater fish diversity, abundance and the heightening effect of the Roseires reservoir, was studied from May 2010 to March 2011 in six sampling sites using experimental fishing nets. The present study has shown that Roseires reservoir supported a total of 34 species of fishes of 13 families were recorded. Among identified fishes, fishes belonging to family Mormyridae were dominated with (7 species) followed by Characidae with (6 species), Cyprinidae with (5 species), Bagridaewith (4 species), Schilbeidae with (3 species) and Cichlidae with two species. According to the relative abundance of fish species Synodontisspecies as the dominant (42.43%), followed by Latesniloticu (12.06%) and thirdly Oreochromisniloticus (6.17%). The potential of the fisheries in the future dam- reservoir (After Heightening) will depend on the area impounded and the dimensions. It will surely be raised at least, may be about two times to the present estimated potential in reservoir; depending on the total surface area to be covered with water. Expected fish species composition will not be very different from the known present status in the reservoir, as the present survey, recovered similar species composition, since the first impoundment, with only slight changes. Keyword - Roseires Reservoir, Biodiversity.Fish Fauna, Expansion and Heightening. I. INTRODUCTION Biodiversity is often ambiguously misused or overused to describe population dynamics of a location or community. It a measure of the numbers of species that make up a biologic community and is considered to be one of the most important aspects of community organization and structure. Species richness and relative species abundance describe key elements of biodiversity(lawson et al., 2010).Fishes are not only important indicators of ecological health and the abundance, but also maintain a balance in the food chain by consuming plankton and small animals and form food for many animals. (Raman andgeanesh, 2016).Reservoirs are an important method of impounding water so that society can ensure that water is available all the year round and they help in maximizing abstraction from rivers. Many of these reservoirs were built as a result of societal demand for drinking and industrial water supplies, irrigation, hydroelectric power generation, fish production and recreation (Mustapha,2011). Reservoirs play a very important role in the geochemical cycling of elements and influence the chemical composition and material transfer of the river system (Abhayet al., 2005). Productivity of a reservoir is dependent on its biogenic capacity to transform solar energy into chemical energy. The energy fixed at primary producer level passes through trophic chain and a fraction of it ends up as fish flesh (Sudhanet al., 2017). Reservoirs are of high ecological, economic and recreational importance (Carol et al., 2006). Sudan is rich in water resource of surface area of more than two million hectares. Nile and it is tributaries constitute the main water resources. There are five man-made lakes within the Nile and its tributaries. Roseires Dam one of the freshwater reservoir in Sudan, was built on the Blue Nile in The potential production of this reservoir was estimated at 1,700 tons/yr. and the actual production was 1,500 tons/yr. (Henderson, 1975), which corresponds closely with the assumed potential sustainable yield. Ahmed (2002) reported that current yield was 1,000 tons/yr. It is also stated by the consultancy report on the impact of heightening Roseires Dam (Karrar and Partners, 1994) that only 1,000 tons/yr. is exploited.the study of fish and their stability is important because fish population of a water body may vary significantly from year to year. The fish fauna is an important aspect of fishery potential of a reservoir. They play an important role, as they are not only useful for food and recreation, but also act as a tool for biological control by feeding upon the planktonic population and aquatic vegetation in the reservoir (Ravindra, 2016). This study aimed to provide baseline information on the fish population structure and the effect of the expansion of Roseires reservoir on fisheries productivity. II. MATERIALS AND METHODS Study area The Roseires reservoir is located in Blue Nile state and lies at 11 47' 54.7" N and 34 23' 36.6" E (Fig 1). The storage season begins from July up to November and the drainage season from February to June. The impoundment extends to some 80 km upstream of the dam and has a surface area of about 290 km 2, mean depth is 10m, maximum depth is 50 m and maximum drawdown is 13m. Based on the proposed survey and preparations, six sampling 30

2 stations were selected as representative of the study area based to covered baseline information on fisheries within the present reservoir and along the inundation area and downstream of the dam location. (Figure2). Fish samples collection Fish samples were collected from six selected localities during the study period from May 2010 to march 2011, using experimental fishing nets (Table 1) which were set on sampling station and left overnight; to be lifted with its catch the following morning. The Fish were obtained from sampling locations were identified using keys provided by (Boulenger, 1907; Sandon,1950; Abu Giederi, 1984; Bailey,1994 and Bishai& Khalil, 1997). Sampled fish were counted for each species and recorded. Relative abundance of species was calculated by dividing number making up a species by the total number of fish sampled multiplied by 100% while relative abundance of families is the number of each fish family divided by total number of fish sampled multiplied by 100%. Unit Length Width Area Mesh Size Twine No Net (m) (m) (m 2 ) (cm) Net Net Net Net Table (1) Experimental gill net specifications used for fish sampling Figure (1):Sudan Nilotic water resources and study area location 31

3 Figure (2): location of study sites RESULTS AND DISCUSSION Fish Biodiversity The present investigation of fish fauna in Roseires reservoir showed that most of the fish species recorded were widely distributed in the lentic and lotic water bodies of Sudan. A total of 34 species of fishes belong to 13 families (Table 2) were recorded. Among identified fishes, fishes of family Mormyridae (7 species) followed by Characidae (6 species), Cyprinidae(5 species), Bagridae(4 species), Schilbeidae(3 species) and Cichlidae two species. 32

4 Fish species were recorded as rarely encountered were, Distichodus sp. Gymnarchusniloticus and Polypterus sp. Two species have not been seen in recent times of study, namely Citharinus sp. and Heterotisniloticus. The higher occurrence of Mormyrids could be due to the suitable environment and good conditions in which found. Blue Nile River, which is a wild environment, possesses features which make the fish to thrive better because it conforms to their basic biological requirements. Karrar and Partners (1994) stated that the fish population of the reservoir is made up of thirty seven (37) species representing twenty eight (28) genera and fifteen (15) families. These species exhibit a wide degree of fluctuation seasonally but with a relatively lesser fluctuation yearly. They also mentioned that since 1966 (date of filling) and afterwards, few changes in the quantity and distribution of fish have been detected. In this study, the fish composition on the species level shows that Synodontis species (42.43%) as the dominant followed by Latesniloticu (12.06%) and thirdly Oreochromisniloticus (6.51%). This results agree with the work of (Karrar and Partners, 1994) who reported that some species gained ground and increased considerably as indicated by: Oreochromisniloticus, Synodontis shall and Mormyruscashive. Abu-Gideiriet al. (2005) reported mainly fish production from both al-gezeira and Sinnar State included Tilapiasp, Latesniloticus and Clariassp whilst the fish production in Blue Nile State included Tilapiasp, Bagrusbayad, Latesniloticus and Mormyrus sp. All these states on the Blue Nile River. The list compiled by Mishrigi (1970) for fishes of Roseires reservoir, did not include several species, mentioned in this study, that could be attributed to the limited area of investigation by the author at that time (though it was expected that the diversity should be more diverse). Fishes not mentioned were:clariaslazera (garepinus), Malapteruruselectricus, Tetraodonfahka, Mormyropsangulloides, Mormyruscachive, Mormyrushassiquilisti, Petrocephalus bane, Synodontis sp. and Auchenoglanis sp. The Fisheries Department of Khartoum State (2003) surveyed al- Gereif fish landing at the Blue Nile within Khartoum city and recorded (22) fish species, Tilapiasp was dominant and followed by Labeo sp., Synodontis sp. and Bagrusbayad respectively, whereas Distichodusniloticus and Protopterusaethiopicus were of less occurrence. Potential for Fisheries Development in the Dam- Reservoir (After Heightening) The potential of the fisheries in the future damreservoir will depend on the area impounded and the dimensions. It will be raised at least, may be about two times to the present estimated potential in reservoir; depending on the total surface area to be covered with water. The heightening of the Roseires Dam is expected to lead to change in the dynamics and distribution of fish; increase in primary productivity of water; promotion on the growth rate of individuals and promotion of the overall fish production.consequently an anticipated development is expected, in the fishing gear and socio-economic life of the fishermen sector (Karrar and Partners, 1994). Expected fish species composition will not be very different from the known present status in the reservoir, as the present survey, recovered similar species composition, since the first impoundment, with only slight changes. Quantities of potential fishes were estimated as 6,600 tons per annum(smec-inception report,2010). This is relatively high compared with (Karar consultancy study,1994). After impoundment,the reservoirwill definitely and significantly changes during 5-10 years, then biodiversity and production of fishes are affected into a similar situation and composition, as it took place in similar local damreservoir(s) as e.g. in Lake Nubia-Nasser and other African Dam-Reservoirs. A larger reservoir is expected to be formed with larger areas and more potential at least with double capacities, based on the final specifications and dimensions to be adopted for the final dam constructed and as a result the damreservoir. Tilapiasp (Bulti), Latesniloticus (Ijle), Alestessp (kawara) and Hydrocynussp( kass) which are typically lacustrine fish species; are expected to flourish and develop more as commercial species with higher grades and value. The fishing of the downstream area, below the proposed dam complex; will be affected positively through reduction of the siltation. The sustainable fish potential which was very much reduced by the siltation and flushing, is expected to revive and flourish. Hence generally the fisheries of the whole Blue Nile River Basin is expected to be positively affected by increase in fisheries resources and in fishing practice and effort to exploit a sustainable potential. 33

5 Family Fish Species Local name Number of fish species Alternative abundance % Characidae Alestes(Brycinus) nurse Heimila Alestesdentex Kawara *Alestesbaremose " '' '' *Alestesmacrolepidotis KawaraSafsaf HydrocynusForskalii Kass HydrocynusLinneatus " " Cichlidae Oreochromisniloticus Bulti Cyprinidae Labeohorie Dabs Labeoniloticus Dabs Labeocoubie Kadan Labeoforskalii Kadan Barbusbynnie Bynnie Claridae Clariaslazera Garmout Centropomidae Latesniloticus Igil Tetraodontidae TetraodonFahka Tambiera Malapteruridae Malapteruruselectricus Barada Schilbieidae Eutropiusniloticus Shilba Shilbemystus " " Shilbeuranoscopus " " Bagridae Bagrusbayad Bayad Bagrusdocmac Kabarose Auchenoglanis Spp. Humar el-hut ChrysichthysAuratus Abu Riala Protopteridae Protopterusaeothopicus Dabeeb El-Hut Polypteridae *Polypterus spp. Um Kuru Mormyridae Mormyruscashive Khasum Banat Mormyruskannume " " *Mormyrushassiquilisti " " Petrocephalus bane Ras Hagar Gnanthonemus Um Shiffa Mormyropsanguloides Taraza Hyperopisusbebe Sawia Mochokidae Synodontisspp. Gargur Table (2) Fish Species Composition Identified Atrosaries Reservoir 60% 5% 3% 5% 2% 17% 0% 3% 0% 4% 1% 0% 0% Characidae Cichlidae Cyprinidae Claridae Centropomidae Tetraodontidae Malapteruridae Schilbieidae Bagridae Protoperidae Polypteridae Mormyridae Fig( 3) Alternative abundance of fish family in Rosaries reservoir 34

6 13% 1% 7% 13% 8% 10% Bagiridae Cichlidae Mormyridae Mochokidae Cyprinidae 39% Characidae Centropomidae 9% Claridae CONCLUSIONS Fig (4) Percentage composition of fish families in Rosaries reservoir according economic value It is necessary to plan and conduct, detailed biological and technical studies besides feasible fishery developmentprojects (for both capture and culture fisheries) to exploit the maximum sustainable expected fishery potential. Hence it is also recommended to conduct more environmental impact assessments of the proposed dam project on the fisheries and aquatic habitat, before and after the completion of the heightening of the dam.for future sustainable exploitation of the expected surplus fish production (as result of heightening the dam); which could be above 4000 tons per annum. It is suggested through Sudanese government should be implemented to help the Fisheries Association to properly utilize the resource. This should cater for development of modern and efficient fishing and processing technologies for the maximum sustainable fish yield and best quality with minimum post-harvest losses. REFERENCES [1] Abhay, K. S., Mondal, G.C., Singh, P.K., Singh, S., Singh, T.B. and Tewary, B.K. (2005). Hydrochemistry of reservoirs of Damodar river basin, India: Weathering processes and Water quality assessment, Environ Geol., 48: [2] Abu Gideri Y.B. (1984) Fishes of Sudan. Sudan, Khartoum University. Press (166p). [3] Abu Gideiri, Y. B., Meshragi, S. Y., Ali, M. E. & Mohammed, A. H. (2005).Problems and Resolutions of Production and Marketing in Managements Fisheries of Federal States and Khartoum State.Ministry of Agriculture, Irrigation and Animal Resources, workshop, Khartoum, Sudan (In Arabic). [4] Ahmed, E. O. (2002). Studies on the Productivity and Fisheries of Khashm El-Girba Reservoir in Relation to Annual Flushing. M. Sc. thesis, Dept. of Zoology, Faculty of Science, University of Khartoum, Sudan. [5] Bailey, R.G. (1994). Guide to fishes of the River Nile in the republic of the Sudan. College. London. UK.p ( ). [6] Bishai, H.M., Khalil, M.T. (1997). Freshwater fishes of Egypt. National Biodiversity Unit,Cabinet of ministers Egyptian Environment Affairs Agency (EEAA), A.R.E. (9), 229pp. [7] Boulenger, G.A. (1907). Zoology of Egypt: The Fishes of the Nile, Hugh Rees PublicationLtd., London, 276 pp. [8] Carol, J., Benejam, L., Alcaraz, C., Vila-Gisper,t.A,, Zamora, L., Navarro, E., Armengol, J. and Garcia-Berthou, E. (2006). The effects of limnological features on fish assemblages of 14 Spanish reservoirs.ecolfreshw Fish., 15: [9] Fisheries Department of Khartoum State (2003).Database Program.Report, Khartoum State, Sudan (in Arabic). [10] Henderson, H.F. (1975). The Fisheries of the Reservoirs of Central Sudan. Cairo, FAO Report, Near East Reg. Office: 5 p. [11] Karrar and Partners (1994).Social and Environmental Impact of Heightening Roseire Dam. Final Report to the Ministry of Irrigation Feb.1994 (Sudan).Main Report,Vol. I -305 pp. [12] Lawson, O. E. and Olusanya, O. M. (2010).Fish Diversity in Three Tributaries of River Ore, South West, Nigeria.Wd. J. of Fi.& Ma. Sci. 2 (6): [13] Mustapha, M.K., (2011). Perspectives in the Limnology of Shallow Tropical African Reservoirs in Relation to Their Fish and Fisheries. The Journal of Transdisciplinary Environmental Studies, 10 ( 1) : [14] Ramanjaneya and Ganesh, C. B. (2016). Fish faunal diversity in Tungabhadra Reservoir, Hosapete, Ballari District, Karnataka. Inter. J. of Re. in Fish.and Aqua, 6(2): [15] Ravindra, R., (2016). Biodiversity Of Fish Fauna In Lakhapura Reservoir, Bhikangaon Tehsil, Khargone District, M.P. International Journal of Innovative Research and Advanced Studies, 3(4) :75-77 [16] Sandon, H. (1950) An illustration guide to the fresh water fishes on the Sudan. Sudan Notes and Rec. 25:61 p. [17] Snowy Mountains Engineering Corporation.(SMEC, 2010). Inception Report -Rosaries Dam Heightening Project - Environmental and Social Impact Assessment -Final (Jan.2010) [18] Sudhan, C., Kingston, D.S., Jawahar, P. and Aanand, S. (2017).Updated checklist of fish species in Pechiparaireservoir, Kanyakumari district, Tamil Nadu.J. of Ento.& Zoo. Stud. 5(4):