Investigation of phytoplankton distributions in the westernmost part of Barrier-lagoon-complex, Western Nigeria

Abstract

Distributions of phytoplankton were studied in two contiguous water bodies (Badagry Creek and Ologe Lagoon) within westernmost part of the Barrier-lagoon complex in Nigeria. Phytoplankton samples were collected and analysed using standard methods at five stations in each of the water bodies in September 2011, February and May 2012. Phytoplankton recorded from the two water bodies belonged to Classes Bacillariophyta, Chlorophtya, Cyanophyta and Euglenophyta. Total phytoplankton species of 92 and 94 were recorded in Badagry Creek and Ologe Lagoon respectively indicating relatively high diversity and productivity of the two water bodies. Bacillariophytes dominated the phytoplankton communities in the two water bodies constituting about 88% and 58% in Badagry Creek and Ologe Lagoon respectively. In terms of abundance, Badagry Creek was dominated by species only from the Class Bacillariophyta whereas each of the Classes Bacillariophyta, Chlorophyta and Cyanophyta had species with very high abundance in Ologe Lagoon. In Ologe Lagoon, two stations close to discharge points of municipal and abattoir wastes had low phytoplankton species number and diversity but high abundance of pollution indicator and harmful species of such genera as Volvox, Microcystis and Oscillatoria. The undesirable effects of the anthropogenic activities and the need to regulate them for sustainable management of the water bodies and the resources therein are discussed.

Keywords: Coastal waters, phytoplankton distribution, phytoplankton abundance, productivity, anthropogenic activities, harmful algae.