Abstract

Temporal variations of the water chemistry and chlorophyll-a dynamics at the Tomaro creek Lagos were investigated for six months (October, 2007 to March, 2008). Temperature remained high (>27°C) all through the sampled period while total suspended solids andtransparency increased in the dry months. Total dissolved solids were high (≥8160 mg/L) between December and March while lower values (≤2529 mg/L) were recorded between October and November. Salinity, conductivity and pH values increased steadily during the sampled months. Chemical oxygen demand and biological oxygen demand values at the site remained low (<12.80 mg/L; ≤2.0 mg/L) between the period free of organic pollution and moderately (≤52.2 mg/L; 7.0 mg/L) organically polluted period. Heavy metals (Pb, Fe, Cu) especially Fe followed almost same pattern as chlorophyll-a recorded. Phytoplanktonabundance dropped (80cells/ml) between November and December. Phytoplankton diversity was high while the species were evenly distributed.

Key words: Tidal creek, water chemistry, chlorophyll-a, phytoplankton