Ecological Status of Opa Reservoir, Obafemi Awolowo University, Ile Ife, based on the Abundance and Diversity of its Planktonic Flora


  • Adebukola Adenike ADEDEJI Obafemi Awolowo University, Department of Zoology, Ile-Ife (NG)
  • Oluseun P. BOLAWA Obafemi Awolowo University, Department of Zoology, Ile-Ife (NG)
  • Yetunde F. TAIWO Obafemi Awolowo University, Natural History Museum, Ile-Ife (NG)



bio-indicator species; phytoplankton; taxonomic composition; trophic status; water quality


A study investigating the spatial and temporal distribution, composition and abundance of plankton in Opa reservoir, Obafemi Awolowo University, Ile-Ife, Southwest Nigeria, was conducted over a period of an annual cycle. The study was undertaken with a view of providing a more recent catalogue of planktonic flora and possibly an update of the reservoir’s trophic status. Quantitative net planktons were collected monthly from both the surface and bottom levels at three sampling stations established at the dam site (lacustrine), mid-lake (transition) and upper inflow (riverine) parts of the reservoir. The divisions recorded were Bacillariophyta > Cyanophyta > Chlorophyta > Euglenophyta > Myzozoa > Ochrophyta = Charophyta > Cryptophyta in order of abundance. Vertically, the highest occurrence of species was recorded at the lacustrine bottom station (71 species), while the least occurrence was observed in the transition bottom station (51 species). A total of sixteen plankton species showed significant seasonal variation in abundance during this study period, while only seven species had significant spatial variation (p ≤ 0.05). Higher abundance was observed during the rainy season (170,797,350 Org/m3 from seventy-two species) than dry season (5,138,400 Org/m3 from forty-nine species). Notable bio-indicator plankton species recorded were Anabaena circinalis, Anabaena flos-aquae, Microcystis sp., Aphanocapsa litoralis and Microcystis aeruginosa. Some other pollution indicator species recorded were Synedra ulna, Oscillatoria agardhii, Phacus sp., Surirella sp., Closterium sp., Aphanocapsa sp. and Euglena sp. Hence, Opa reservoir is very rich in Bacillariophyta (diatoms), followed by Cyanophyta (blue-green) and Chlorophyta (green algae), which are known to characterize eutrophic lakes. 


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Abowei JFN, Tawari CC, Hart AI, Garricks DU (2008). Fin fish species composition, abundance and distribution in the lower Sombreiro River, Niger Delta, Nigeria. International Journal of Tropical Agriculture and Food Systems 2(1):46-43.

Abowei JFN, Ezekiel EN, Hansen U (2012). Effects of water pollution on phytoplankton species composition in Koluama Area, Niger Delta Area, Nigeria. International Journal of Fisheries and Aquatic Sciences 1(2):134-139.

Achionye-Nzeh CG, Isimaikaiye A (2010). Fauna and flora composition and water quality of a reservoir in Ilorin, Nigeria. International Journal of Lakes and Rivers 3(1):7-15.

Adedeji AA, Komolafe OO, Akinrele OA, Adeleke O (2015). Water quality and plankton biota of Osinmo reservoir, Osun state, South-west Nigeria, Zoology and Ecology 25(2):145-153.

Adeniyi IF (1978). Studies on the physicochemical factors and planktonic algae of Lake Kainji, Nigeria. PhD Thesis. University of Ife, Ile-Ife.

Adeniyi IF, Adedeji AA (2007). The Rotifera fauna of Gongola River basin, Northeast Nigeria. Ife Journal of Science 9(1):1-16.

Adesakin TA, Adedeji AA, Aduwo AI, Taiwo YF (2017). Effect of discharges from re-channeled rivers and municipal runoff on water quality of Opa reservoir, Ile-Ife, Southwest Nigeria. African Journal of Environmental Science and Technology 11(1):56-70.

Akinbuwa O, Adeniyi IF (1991). The Rotifera fauna of Opa reservoir, Ile-Ife, Nigeria. Journal of African Zoology 105(5):383-391.

Akinbuwa O, Adeniyi IF (1996). Seasonal variation, distribution and interrelationships of Rotifers in Opa Reservoir, Nigeria. African Journal of Ecology 34:351-363.

Atobatele OE (2013). Pelagic phytoplankton succession pattern in a tropical freshwater reservoir (Aiba Reservoir, Iwo, Osun state, Nigeria). Bioremediation, Biodiversity and Bioavailability 7(1): 81-84.

Benedict OO, Gabriel UI (2012). Distribution and dynamics of a tropical waterfalls ecosystem. International Journal of Ecosystem 2(1):28-37.

Beyruth Z (2000). Periodic disturbances, trophic gradient and phytoplankton characteristics related to cyanobacterial growth in Guarapiranga reservoir. Sao Paulo State, Brazil. Hydrobiologia 424(1):51-60.

Bolawa OP (2016). A study of the spatial and temporal diversity and abundance of planktonic flora and fauna of Opa Reservoir, Ile Ife, Southwest, Nigeria. MSc Thesis. Department of Zoology, Obafemi Awolowo University, Ile-Ife, Osun state, Nigeria.

Bwalla RL, Ovie SI, Ajayi O, Haruna A (2010). Preliminary study on the limnology and plankton abundance in relation to fish production in some NIFFR Reservoirs. Report Opinion 2(6):7.

Codd GA (1995). Cyanobacterial toxins: Occurrence, properties and biological significance. Water Science and Technology 32:149-156.

Davies OA, Abowei JFN, Tawari CC (2009). Phytoplankton community of Elechi Creek, Niger Delta, Nigeria: A nutrient polluted tropical creek. American Journal of Applied Science 6(6):1143-1152.

Edward JB, Ugwumba AAA (2010). Development trends and evaluation of Egbe reservoir water nutrient status in Ekiti State, Nigeria. Journal of Life Sciences 4(1):26.

Emmanuel BE, Onyema IC (2007). The plankton and fishes of a tropical creek in south western Nigeria. Turkish Journal of Fisheries and Aquatic Science 7:105-113.

Fawole OO, Arawomo GAO (2000). Fecundity of Sarotherodon galilaeus (Pisces: Cichlidae) in the Opa reservoir, Ile-Ife, Nigeria. Revista de Biología Tropical 48(1):201-204.

Hecky RE, Kling HJ (1981). The phytoplankton and protozooplankton of the euphotic zone of Lake Tangayinka: Species composition, biomass, chlorophyll content and spatio-temporal distribution. Limnology and Oceanography 26:548-564.

Jaji MO, Bamgbose O, Odukoya OO, Arowolo TA (2007). Water quality assessment of Ogun River, Southwest Nigeria. Environmental Monitoring and Assessment 133(1-3):473-482.

Magurran AE (2004). Measuring biological diversity. 2nd edition Oxford, U.K: Blackwell Science Ltd.

Margalef R (1951). Diversidad de especies en las comunidales naturales. [Diversity of species natural areas]. Public Institute of Applied Biology 9:5-27.

Menhinick EF (1964). A comparison of some species-individuals diversity indices applied to samples of field insects. Ecology 45:859-861.

Moshood KM (2009). Phytoplankton assemblage of a small, shallow, tropical African reservoir. International Journal of Tropical Biology 57(4):1009-1025.

Nkwoji JA, Onyema IC, Igbo JK (2010). Wet season spatial occurrence of phytoplankton and zooplankton in Lagos Lagoon, Nigeria. Scientific World Journal 5(5):7-14.

Nwankwo DI, Akinsoji A (1992). Epiphyte community of water hyacinth, Eichhornia crassipes (MART) Solms in coastal waters of South Western Nigeria. Archiv fur Hydrobiologie 124(4):501-511.

Offem BO, Ayotunde EO, Ikpi GU, Ada FB, Ochang SN (2011). Plankton-based assessment of the trophic state of three tropical Lakes. Journal of Environmental Protection 2:304-315.

Ogamba EN, Chinda AC, Ekweozor IKE, Onwuteaka JN (2004). Water quality and phytoplankton distribution in Elechi Creek Complex of the Niger-Delta. Journal of Nigerian Environmental Society 1(2):121-130.

Olasehinde KF, Abeke AA (2012). Limnological features of Ikere Gorge Reservoir, Iseyin south-western Nigeria: Plankton composition and abundance. Journal of Biology and Environmental Sciences 2(6):20-31.

Park S, Brett MT, Oshell ET, Goldman CR (2003). Seston food quality and Daphnia production efficiencies in an oligo-mesotrophic Subalpine lake. Aquatic Ecology 37:123-136.

Pielou EC (1966). The measurement of diversity in different types of biological collections. Journal of Theoretic Biology 13:131-144.

Reynolds CS (1999). Non-determinism to probability, or N:P in the community ecology of phytoplankton: Nutrient ratios. Archiv für Hydrobiologie 146:23-35.

Salem TA (2011). Variation in phytoplankton along different zones of Aswan High Dam Reservoir. Egypt Journal of Aquatic biology and Fishery 15:87-104.

Shannon CE, Weaver W (1949). The mathematical theory of communication. Urban University, Illinois Press, Illinois.

Simciv T (2005). The role of plankton, zoobenthos, and sediment in organic matter degradation in oligotrophic and eutrophic mountain lakes. Hydrobiologia 532:69-79.

SPSS (Statistical Package for Social Sciences) (2012). Statistical Package for the Social Sciences Base 21 for Windows. Chicago, IL: SPSS

Taub DM (1984). Primate Paternalism. Burkhuys Publishers. New York, USA.

Townsend CR, Harper JD, Begon M (2000). Essentials of ecology. 3rd edition, Blackwell Science, London, UK.

Ugwumba AAA, Anago IJ, Esenowo IK (2013). The physicochemistry and plankton diversity of Awba Reservoir University of Ibadan, Ibadan Nigeria. Research Journal of Environmental and Earth Sciences 5(11):638-644.

Ugwumba AO, Ugwumba AAA (1993). A study of the physico-chemical hydrology and plankton of awba Lake in Ibadan, Nigeria. Fish Academic Communication 1:20-39.

Walsh CJ, Sharpe AK, Breen PF, Sonneman JA (2001). Effects of urbanization on streams of the Melbourne region, Victoria, Australia. I. Benthic maroinvertebrates communities. Freshwater Biology 46:535-551.

WHO (2009). World Health Organization Annual Report. International Standards for drinking water, WHO Geneva, 1st Edition.

Yao H, Qian X, Gao H, Wang Y, Xia B (2014). Seasonal and spatial variations in heavy metals in two typical Chinese Rivers: Concentrations, environmental risks and possible sources. International Journal on Environmental Resource and Public Health 11:11860-11878.

Zabbey N, Sikoki FD, Erondu J (2008). Plankton assemblages and environmental gradients in the middle reach of the Imo River, Niger Delta, Nigeria. African Journal of Aquatic Science 33(2):241-248.




How to Cite

ADEDEJI, A. A., BOLAWA, O. P., & TAIWO, Y. F. (2018). Ecological Status of Opa Reservoir, Obafemi Awolowo University, Ile Ife, based on the Abundance and Diversity of its Planktonic Flora. Notulae Scientia Biologicae, 10(2), 287–296.



Research articles
DOI: 10.15835/nsb10210248