Abundance and Dynamics of Centric Diatom Coscinodiscus and Pennate Diatom Pluerosigma in Atlantic Ocean (Nigeria), Gulf of Guinea

Abstract

Diatoms which are classified into centric diatoms and pPennate diatoms play vital role in themarine food chain. Hence, the objective of this paper is to evaluate the abundance, distribution, dynamics and occurrence of Coscinodiscus and Pluerosigma in Atlantic Ocean from Bight of Benin to Bight of Bonny in Nigeria. This study considered the abundance, dynamics and environmental factors influencing the distribution of centric and pennate diatoms in the Atlantic Ocean, Gulf of Guinea (Nigerian). Water samples for diatom analysis and physico-chemical analysis were collected along transect of the Atlantic Ocean (Nigerian) from Twenty (30) oceanic water stations in ten (10) locations from the eight (8) Nigerian coastal states. Eight taxa each of centric and pennate diatoms were found in the Atlantic Ocean. Coscinodiscus radiatus was the most widely distributed and abundant among centric diatom Coscinodiscus while Pleurosigma enlongatum was the most widely distributed species for the pennate diatom Pleurosigma. Coscinodiscus maginatus was least in distribution and abundant for the centric diatom Coscinodiscus while Pleurosigma formosum and Pleurosigma P. formosum v. longissimum were least occurring among the pennate diatom Pleurosigma. Ondo oceanic water was richest in the diversity of Coscinodiscus in Gulf of Guinea while Bayelsa oceanic water was richest in the diversity of Pleurosigma in Gulf of Guinea. Result revealed significant difference in the abundance of centric and pennate diatoms in the Atlantic Ocean. Temperature, pH, total dissolved solids, salinity, alkalinity, total hardness calcium, chloride silicate, sulphate and rainfall were environmental factors controlling the distribution and abundant of pennate and centric diatoms.