Effect of Water Quality Indices on Phytoplankton of a Sluggish Tidal Creek in Lagos, Nigeria

1T.A. Adesalu; D.I. Nwankwo

Effect of Water Quality Indices on Phytoplankton of a Sluggish Tidal Creek in Lagos, Nigeria

2008

1T.A. Adesalu | D.I. Nwankwo

The phytoplankton of a tidal creek in Lagos was investigated for six months (September 1998- February 1999).The physico-chemical environment was essentially neutral (pH 7.00-7.30), relatively more transparent (>0.23 m), expressed higher conductivity (>0.10 mS cm-1), higher chloride values (>23.48 mg L-1), lower nitrate content (<0.70 mg L-1), lower sulphate values (<0.45 mg L-1) and phosphate values (<0.12 mg L-1) in the dry months. In the wet months, September to November 1998, conductivity (<0.16 mS cm-1), transparency (<0.80 m), salinity (<0.04%), dissolved oxygen (<24.00 mg L-1), chloride (<24.21 mg L-1) and phosphate (< 0.21 mg L-1) were recorded. The phytoplankton was dominated by diatoms (48 pennate forms and 23 centric forms).The other algal groups comprised six blue- green algae and six green algae. Species richness (d) was high in stations nearer the Lagos lagoon for the six sampling periods. Shannon-Weaver index (H1) was lowest in November 1998 and highest in October 1998 and February 1999 while evenness of species J was low (<0.71) throughout the period. Higher phytoplankton biomass was recorded in the dry months than wet months.

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