Influence of In-stream Ecosystem Restoration Techniques on the Fish Ecology of the River Nabongo in Eastern Uganda

Remigio Turyahabwe(1), Muhamud Wambedde Nabalegwa(2), Joyfred Asaba(3), Andrew Mulabbi(4*)

(1) Department of Geography, Faculty of Science and Education, Busitema University, Tororo, Uganda
(2) Department of Geography and Social Studies, Faculty of Arts and Social Sciences, Kyambogo University, Kampala, Uganda
(3) Department of Geography and Social Studies, Faculty of Arts and Social Sciences, Kyambogo University, Kampala, Uganda
(4) Department of Humanities, Faculty of Education, Muni University, Arua, Uganda
(*) Corresponding Author


The study was the first in Uganda to assess the responses of fish community assemblages to introduced woody debris structures in a tropical river in Eastern Uganda. For comparison purposes, two different woody debris structures (simple and complex) were introduced in river Nabongo, and their effect on fish assemblage and feeding was established based on experiments conducted in two heterogeneous stream environments (a pool and a riffle). Results showed that sampling plots treated with restoration structures registered higher fish species richness, diversity, and abundance than sampling plots without restoration structures (control plots) at each site. The study (experiment) applied a stratified sampling design which used purposive identification of a pool and a riffle in River Nabongo Catchment. Fish were captured using a drift net, an electro-fishing gear, and a hand net. Data were analysed using a one-way ANOVA generated from STATA version 14. At the pool site, total fish density varied significantly from plot to plot (P<0.05) but was highest in the complex structures with 64±1.08 fishes/m2 and lowest with 24±0.82 fishes/m2 in untreated plots. K-factor did not vary significantly in untreated plots at the pool site but significantly differed from treated plots at P<0.05. The relative abundance of fish species at the pool site was highest in the complex structures with 40.7±0.66% and 21.5±0.42% before structures but was least in the control plot, varying significantly from plot to plot at P<0.05. It was concluded that woody debris restoration is an effective stream restoration technique. Fish individuals, trophic groups, and taxa more densely colonised sampling plots that had structures than those that did not have structures.


Feeding group; fish metrics; K-factor; sampling plots; taxonomic composition

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Aazami, J., A. Esmaili-Sari, A. Abdoli, H. Sohrabi & P.J. Van den Brink. 2015. Monitoring and assessment of water health quality in the Tajan River, Iran using physicochemical, fish, and macroinvertebrates indices. J Environ Health Sci Engineer. 13 (29).

Angermeier, P.L & MR. Winston. 1998. Local vs regional influences on local diversity in stream fish communities of Virginia. Ecology. 79 (3): 911-927.[0911:LVRIOL]2.0.CO;2

Barnham, C & A. Baxter. 1998. Condition factor K for salmonid fish. Fisheries notes FN0005, ISSN 1440-2254. 236-245.

Beechie, T & S. Bolton. 1999. An approach to restoring salmonid habitat-forming processes in Pacific Northwest watersheds. Fisheries. 24 (4): 6-15.;2

Benke, A & J.B. Wallace. 2010. Influence of wood on invertebrate communities in streams and rivers. In In: Gregory, S.V; Boyer, K.L; Gurnell, A.M eds. The ecology and management of wood in world rivers. American Fisheries Society, Symposium 37: Bethesda, Maryland. 37: 149-177.

Benke, A, C.,R.L. Henry, D.M. Gillespie & R.J. Hunter. 1985. Importance of snag habitat for animal production in southeastern streams. Fisheries. 10 (5): 8-13.;2

Bilby, R.E. 2003. Decomposition and nutrient dynamics of wood in streams and rivers. In S. V. Gregory, K.L. Boyer, and A.M. Gurnell, (eds). The ecology and management of wood in world rivers(pp135-147). American Fisheries Society, Symposium 37, Bethesda, Maryland.

Brooks, A.P., P.C. Gehrke, J.D. Jansen & T.B. Abbe. 2004. Experimental reintroduction of woody debris on the Williams River, NSW: Geomorphic and ecological responses. River Research and Applications. 20: 513-536.

Cederholm, C.J., R.E. Bilby, P.A. Bisson, T.W. Bumstead, B.R. Fransen, W.J. Scarlett & J.W. Ward. 1997. Response of juvenile coho salmon and steelhead to the placement of large woody debris in a coastal Washington stream. North American Journal of Fisheries Management. 17 (4): 947-963.;2

Crook, D & A.I. Robertson. 1999. Relationships between riverine fish and woody debris: Implications for lowland rivers. Marine Freshwater Research. 50 (8): 941-953.

Deacon, A.E., R. Mahabir, D. Inderlall, I.W. Ramnarine & A.E. Magurran. 2017. Evaluating detectability of freshwater fish assemblages in tropical streams: Is hand seining sufficient? Environmental Biology of Fishes. 100 (7): 839-849.

DeVore, P & R.J. White. 1978. Daytime responses of brown trout (Salmo trutta) to cover stimuli in stream channels. Transactions of the American Fisheries Society. 107 (6): 763-771.;2

Froese, C.L. 2006. Condition factor and Weight-length relationships: History, Meta-analysis and recommendations. Journal of Applied Ichthyology. 22 (4): 241-253.

Gerhard, M & M. Reich. 2000. Restoration of streams with large wood: Effects of accumulated and built-in wood on channel morphology, habitat diversity, and aquatic fauna. International Review of Hydrobiology. 85 (1): 123-137. CO;2-T

Greenwood, P.H. 1966. The Fishes of Uganda 2nd Edition, Uganda society, Kampala.

Gurnell, A.M., H. Piégay, F.J. Swanson & S.V. Gregory. 2002. Large wood and fluvial processes. Freshwater Biology. 47 (4): 601-619.

Hrodey, P.J & T.M. Sutton. 2008. Fish community response to half-log additions in warm water streams. North American Journal of Fisheries Management. 28 (1): 70-80.

Hynes. S & T. Hennessy. 2012. Agriculture, Fisheries, and food in the Irish economy. The World Economy. 35 (10): 1340-1358.

Leal, C.C. 2012. The Effects of Restored Aquatic Large Woody Debris Structures on Invertebrate Populations in the Napa River. Master’s Theses. 4240.

Lehtinen, R.M., ND. Mundahl & J.C. Madejczyk. 1997. Autumn use of woody snags by fishes in backwater and channel border habitats of a large river. Environmental Biology of Fishes. 49: 7-19.

Mathooko, J.M & CO Otieno. 2002. Does the surface textural complexity of woody debris in lotic ecosystems influence their colonisation by aquatic invertebrates? Hydrobiologia. 489: 11-20.

Minello, T.J & R.J. Zimmerman. 1983. Fish predation on juvenile brown shrimp, Penaeus aztecus Ives: The effect of simulated Spartina structure on predation rates. Journal of Experimental Marine Biology and Ecology. 72: 211-231.

NEMA. 2004. The state of the environment report for Uganda, NEMA Kampala, Uganda

NEMA. 2008. The state of the environment report for Uganda, NEMA Kampala, Uganda

Nsubuga, F.W.N., J.O. Botai, J.M. Olwoch, C.J. de Wet Rautenbach, A.M. Kalumba, P.L. Tsela, A.M. Adeola, A.A. Ssentongo & K.F. Mearns. 2015. Detecting changes in surface water area of Lake Kyoga sub-basin using remotely sensed imagery in a changing climate. UPSpace Institutional Repository.

O’Connor, N.A. 1991. The effects of habitat complexity on the macroinvertebrates colonising wood substrates in a lowland stream. Oecologia 85: 504-512.

Ricker, W.E. 1975. Computation and interpretation of biological statistics of fish populations. Bulletin of the fisheries research board of Canada. 191: 1-382.

Roni, P, T.J. Beechie, R.E. Bilby, F.E. Leonett, M.M. Pollock & G.R. Pess. 2002. A review of stream restoration techniques and a hierarchical strategy for prioritising restoration in Pacific Northwest Watersheds. North American Journal of Fisheries Management. 22 (1): 1-20.;2

Schneider, K.N & K.O. Winemiller. 2008. The structural complexity of woody debris patches influences fish and macroinvertebrate species richness in a temperate floodplain-river system. Hydrobiologia. 610 (1): 235-244.

Shields, F.D., S.S. Knight, N. Morin & J. Blank. 2003. Response of fishes and aquatic habitats to sand-bed stream restoration using large woody debris. Hydrobiologia. 494 (1): 251-257.

Sundland, K & I. Na¨slund. 1998. Effects of woody debris on the growth and behaviour of brown trout in experimental stream channels. Canadian Journal of Zoology. 76: 56-61.

TEEB. 2013. The economics of ecosystems and biodiversity (TEEB) for water and wetlands, TEEB report. IEEP, London and Brussels, Ramsar Secretariat, Gland.

Turyahabwe, R., C. Mulinya & W.A. Shivoga. 2020. Influence of land use/cover on water quality in the RiverSironko catchment area, Eastern Uganda. IOSR Journal of Environmental Science, Toxicology and Food Technology (IOSR-JESTFT). 14 (8): 26-36.

Turyahabwe. R., A. Mulabbi. J. Asaba & M. Olowo. 2021. Ecological responses of macroinvertebrates to an in-stream ecosystem restoration technique in a tropical stream in eastern Uganda. East African journal of environment and natural resources. 3 (1):129-144.

Willis, S.C., K.O. Winemiller & H. Lopez-Fernandez. 2005. Habitat structural complexity and morphological diversity of fish assemblages in a neotropical floodplain river. Oecologia 142: 284-295.

Winemiller, K.O., A.S. Flecker & D.J. Hoeinghaus. 2010. Patch dynamics and environmental heterogeneity in lotic ecosystems. J. N. Am. Benthol. Soc. 29 (1): 84-99.


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