River waters and sediments of the marine ecological systems are habitats to diverse species and biodiversity for their position and complexities as major recipient of pollutants from natural and anthropogenic sources. Polycyclic Aromatic Hydrocarbons (PAHs) account for the abiotic synthesis of materials resulting in carbon-based pollutions in the natural environment at elevated concentrations. These ecotoxic stressors are oftentimes bequeathed as legacies with increasing potencies and reactivity in surface waters and bottom sediments of the marine environment. Crude oil spills from hydrocarbon exploration and illicit artisanal refineries have become major cause of marine ecological pollutions affecting aquatic life and humans in the Niger Delta. Descriptive and comparative statistics designs were adopted in this study to evaluate the environmental and public health implications of seasonal (dry and wet/rainy) levels of marine ecological bioavailability and characteristics of PAHs in the waters and bottom sediments of the contiguous saline differentiated coastal deltaic Lower Orashi and Sombriero River Systems, Rivers State, Nigeria; to determine the extent of PAHs pollution