SPATIAL AND TEMPORAL OCCURRENCE OF PHYTOPLANKTON AND ZOOPLANKTON IN AKOMOJE WATER RESERVOIR, ABEOKUTA, OGUN STATE, NIGERIA.
Keywords:
Temporal, Spatial, Diversity, Phytoplankton, Zooplakton, AbundanceAbstract
The present study was carried out to examine the monthly spatial and temporal occurrence of phytoplankton and
zooplankton in Akomoje water reservoir, Abeokuta, Ogun State Nigeria. This was carried out for eighteen months
between March, 2018 and August, 2019 in four different sampling stations (Odo water, Oke Dam, Odo Onigi and
Odo Onigi). The diversity indices of plankton data were carried out using Shannon-wiener's index (H), Simpson's
index of heterogeneity (D), Margalaf's Index (d), Reciprocal of Simpson index (Dr), Jaccard's coefficient and
Sorensen Index. A total of thirty (30) species belonging to seven (7) groups were recorded for the phytoplankton
and the groups were Cynophyceae, Baccillariophyceae, Euglenophyceae, Dinophyceae, Chlorophyceae,
Zygnomataceae and Chanophyta while the zooplankton reported were twenty-two (22) species found in five (5)
groups and the groups were Rotifera, Protozoa, Copepoda, Cladocera, and Ostracoda and they were all widely
distributed in the four investigative stations. Phytoplankton indicated that Baccillariophyceae (42.53%) was the
most predominant taxon, followed by Cynophyceae 21.92% and Euglenophyceae (16.97%), while the least taxon
was Dinophyceae 1.32%. Zooplankton revealed that most abundant taxon was Rotifer having a relative
abundance of 29.91%, and the second predominant taxon was Protozoa 24.57% followed by Cladocera 23.59%
and Copepoda (20.26%), while the least taxon was Ostracoda 1.67%. It was concluded that the low compositions,
diversity and abundance of plankton in the Akomoje water reservoir could be said to be moderately polluted as at
the period of this study due to runoff from agriculture and human activities around the reservoir. Hence, corrective
measures should be put in place on the dangerous effects of dumping untreated wastes and effluents into the water
body and public enlightenment programme should be routinely organized.
