Abstract: The consistency of the aquatic environment at any point reflects basin lithology, anthropogenic input and climatic conditions. Spatial and seasonal distribution of heavy metal pollution in tropical Lagoon off the Gulf of Guinea was investigated between November, 2018 to October, 2019. Water samples were collected bi-monthly for heavy metal analysis and physicochemical parameters were measured in-situ every month. Results for physicochemical parameters were presumed to be ideal for marine life for both seasons as prescribed by the Federal Ministry of Environment. Salinity showed a significant negative correlation with temperature and a significant positive correlation with electrical conductivity (EC) during wet season. During the dry season, temperature showed a significant positive correlation with pH. As the temperature rises, molecular vibrations increase which results in the ability of water to ionize and form hydrogen ions and resulted into pH drop. The trend of heavy metal concentrations in the entire study area during the wet and dry season were in the order: Pb>Cu>Zn=Cr>Cd and Cu>Cr>Zn=Cd>Pb respectively. Nemerow’s Pollution Index (NPI) and Contamination Index (CI) were further used to evaluate pollution status of each metal in each sample station and contamination status of the entire sample stations respectively. The CI of the study area showed a decreasing order: Apapa > Iddo > Makoko > Ibeshe > Egbin and Ibeshe > Makoko > Iddo > Apapa > Egbin for wet and dry seasons respectively. Keyword: tropical Lagoon, Gulf of Guinea, Physicochemical, heavy metal, Nemerow’s Pollution Index, Contamination Index
Dynamics of heavy metal Pollution in Tropical lagoon of Gulf of Guinea, West Africa
