Department of Animal and Environmental Biology, University of Benin, P. M. B. 1154, Benin City, Nigeria
Omoigberale, M.O., Department of Animal and Environmental Biology, University of Benin, P. M. B. 1154, Benin City, Nigeria; Ogbeibu, A.E., Department of Animal and Environmental Biology, University of Benin, P. M. B. 1154, Benin City, Nigeria
The impact of crude oil exploration on the crustacean zooplankton of Osse River, Edo State (Nigeria) was investigated at five sites between July 2000 and June 2002. Cladocera accounted for 60.85% of the total number of organisms collected from all the five stations, while Copepoda contributed 39.15%. Chydoridae, the only cladoceran family was represented by 11 taxa of two subfamilies, Aloninae (7) and Chydorinae (4). The overall abundance of Cladocera was significantly different (P < 0.05) among the stations. posteriori Duncan Multiple Range (DMR) test showed that the abundance of Cladocera was significantly higher (P < 0.05) in 3 stations, whereas, Copepod abundance was significantly higher (P < 0.05) in 2 stations. The diversity indices revealed the highest and the lowest taxa richness, while Shannon-Wiener and Evenness indices were higher in 3 stations. The temporal dynamics revealed higher faunal abundance during the dry season.