Author/Authors :
Adekunle، I M نويسنده Department of Environmental Management and Toxicology, Department of Fisheries and Aquaculture, University of Agriculture, P.M.B. 2240, Abeokuta, Nigeria , , Ajijo، M R نويسنده Department of Environmental Management and Toxicology, Department of Fisheries and Aquaculture, University of Agriculture, P.M.B. 2240, Abeokuta, Nigeria , , Adeofun، C O نويسنده Department of Environmental Management and Toxicology, Department of Fisheries and Aquaculture, University of Agriculture, P.M.B. 2240, Abeokuta, Nigeria , , Omoniyi، I T نويسنده Department of Environmental Management and Toxicology, Department of Fisheries and Aquaculture, University of Agriculture, P.M.B. 2240, Abeokuta, Nigeria ,
Abstract :
Identification and enumeration of phytoplankton species from Ilaje and Lagos sectors
of the Nigerian coastal waters were conducted using standard procedures. Effects of different crude
oil concentrations (6 to 50 ppm) on population of Coscnodiscus centralis, Thalassionema
frauenfeldii, Odontella mobiliensis, and Ceratium trichoceros at different exposure periods (6 to 42
h) via microcosm experiments were then assessed. Results showed that the phytoplankton species
consisted of diatoms (83.33%) and dinoflagellates (16.67%) whose abundance ranged from 2 to 516
Cell/mL. Crude oil toxicity varied from 0.06 to 36.43% for C.centralis, 1.41 to 35.58% for C.trichoceros,
1.71 to 46.11% for T.frauenfeldii and 0.66 to 44.90% for O.mobiliensis and showed direct relationship
(r -+ 0.81 to +0.97; p < 0.001) with concentration but inverse with exposure period (r = -0.83 to – 0.90;
p < 0.001). Vulnerability within 24-h contact decreased in the order: T.frauenfeldii > O.mobiliensis >
C.centralis > C.trichoceros. Study is a contribution to the scarce data bank on crude oil doseresponse
assessment on plankton species in Nigeria, demonstrating that influx of crude oil into the
Nigerian coastal waters is a risk factor to ecological status.
