Pages: (14-23 )
Abstract
The concentrations of chloroplast-based pigments molecules found in plants, algae and cyanobacteria which photosynthesize in a freshwater swamp in Lagos State, Nigeria were monitored bi-monthly from October, 2017 to March, 2018 in relation to water chemistry changes. The physico-chemical parameters recorded for this study were temperature (27 - 32 °C), rainfall (0 – 154.50 mm), salinity (0.10 – 0.70 ‰), total suspended solids (5 - 69 mg/L), nitrate (0.61 – 8.11 mg/L), silica (1.07 – 16.20 mg/L), phosphate (1.32 – 6.58 mg/L), nickel (0.0002 – 0.0015 mg/L), manganese (0.01 – 0.07 mg/L), iron (0.08 – 0.19 mg/L), chlorophyll a (1.00 – 12.00 μg/L), chlorophyll b (0.10 - 0.50 μg/L) and phaeophytin a (0.10 - 0.30 μg/L). Photosynthetic pigments were significantly positively correlated (p < 0.05) with nitrogen-based nutrients and heavy metals. Significant negative correlation (p > 0.05) on the other hand were recorded between the photosynthetic pigments and salinity, phosphate, sulphate, total suspended solids and potassium. The water chemistry parameters showed variations linked with rain induced floodwater inflow from the surrounding wetland areas. Increasing salinity was a limiting factor to the increase in photosynthetic pigments concentration in this environment.
Keywords: Algal pigments, Chlorophyll, Wetland, Water Chemistry, Heavy Metals,