A Study of the Plankton and Benthos of Ekole River in Bayelsa State, Nigeria

  • Flora E
  • Olaife O
  • Leilei K E
Keywords: Plankton, Benthos, Ekole River, Pollution indicators


A study was undertaken to determine the plankton and benthos of Ekole River in Bayelsa State of   Nigeria. Surface water and sediment samples were collected in the dry (December-January) and wet (June –July) seasons between 2003 and 2004 for plankton and benthic analyses. The water temperature ranged from 27-33°C, pH 6.30-7.5, total suspended solids (T.S.S) 110-282 mg/L, Chloride 15.40-39.6 mg/l, dissolved oxygen 4.11-10.83 mg/l and conductivity 64.5-84.55μS/cm. The total plankton count ranged between 267 x 10³ and 11830 X 10 ³ / L. Forty three and forty seven species of phytoplankton belonging to five families were identified in the dry and rainy seasons respectively. The mean zooplankton population ranged from 1954 x 10 / L in the dry to 3479 x 10 / L in the wet season while the benthic organisms ranged from 113 x 10 / L to 152 x 10 /L in the rainy and dry seasons    respectively. Bacillariophyceae dominated the phytoplankton while the rotifers dominated the zooplankton species. Some biological indicators of pollution: larval forms of Chironomids ,Odonatans and Ephemenopterans  were also identified in the river.


Adegbie, A.T., Dublin Green, C.O. 1998. Foraminiferal Fauna of the Gulf of Guinea Nearshore Sediments: Implication for Sedimentation Processes. NIOMR, Lagos. In: Near shore Dynamics and Sedimentology of the Gulf of Guinea, Pp 113-126.

Ajao, E.A. 1991. Environmental Problems in Coastal Fish Production in Nigeria. In: Tobor ,J.G and Ezenwa , B.I. (eds.). Proceedings of the Fourth Anniversary Seminar of CODRI 10th December, 1991, Nigerian Institute of Oceanography and Marine Research ( NIOMR).

APHA.1992. Standard Methods for the Examination of Water and Wastewater. Eighteenth Edition. American Public Health Association, Washington D.C.

ASTM. 1992.Standard Guide for Collection, Storage, Characterization and Manipulation for Toxicological Testing, E1391-90, vol .11p 04
Clarke, R. 1994. The Pollution of Lakes and Reservoirs. United Nations Environmental Programme, Environmental Library, No 12, Nairobi, Kenya.

Courant, R., Powell, C.B., Michel, J. 1985. Water type Classification for Niger Delta and Creek Waters. In: The Petroleum Industry and the Nigerian Environment. Proceedings of joint FMWHA And NNPC conference on Environment, November 11-14, 1985, Kaduna ,Nigeria pp 295-310.

Delince , G.1992. The Ecology of the Fish Pond Ecosystem, with Special Reference to Africa, Kluwer Academic Publishers, London, pp3-4.

Dublin-Green, C.O. 1994. Benthic Foraminifera as Pollution Indicators in the Bonny Estuary, Niger Delta. Nigerian Institute for Oceanography and Marine Research Technical Paper No 76 pp1-29.

Odiete ,W.O.1999 .Environmental Physiology of Animals And Pollution. Diversified Resources Limited, Lagos. Pp220-246

WQMP.1985. Student Handbook for Water Quality Monitoring. Department of Environmental Resources, Commonwealth of Pensylvania, Office of Resource Management Bureau of State Parks. ER SP-EE-107/88, Pensylvania.