Short-term effect of diesel oil on phytoplankton species in Great Kwa River Mangrove Swamp, S. E. Nigeria

Abstract

Short-term effect of Nigerian diesel oil was tested on the phytoplankton species in Great Kwa River mangrove swamp for 72 hours. Coscinodiscus excentricus showed a great enhancement in growth by increasing tremendously from 7 cells/ml to 16 cells/ml 24 hours after pollution while Hydrodictyon sp. decreased from 5 cells/ml to 2 cells/ml. Rhizosolenia obtuse and Dictyocysta dilatata showed intermediate growth enhancement by appearing 48 hours after polluting the site. Anabaenopsis raciborskii, Closterium stirogosum and Spirotaenia condensata were the most sensitive to diesel oil as they never appeared in the 72 hour sample. The present study reveals that these phytoplankton species can recolonize a diesel polluted area with time, and thus be used as bioindicators for pollution monitoring