Sedimentary Assessment of Basic River in the Niger Delta: A Case Study of Orashi River in the Eastern Niger Delta of Nigeria

Ecosystem in the Niger Delta has become a sanctuary for most endangered species, including mangrove and several forest reserve. The ketstone role of River Orashi in the Niger Delta is remarkable. The quality of River sediment very key in defining the bioavailability of aquatic system. The sedimentary assessment of River Orashi was carried out in six sampling stations (Mbiama, Agbo, Akiogbologbo, Okaki and Okparaki), in both Dry and wet seasons. Result showed that; pH ranged from 6.53 - 7.05, while Electrical Conductivity ranged from 124.31 – 590.01 μS/cm. While nitrite was 0.12 - 0.47 mg/kg, nitrate ranged from 0.72 – 3.76 mg/kg. The values of Sulphate and Phosphate were; 0.33 - 0.85 mg/kg and 0.24 - 0.43 mg/kg. Calcium ranged from 3.68 – 8.03 mg/kg, while magnesium was 1.99 – 6.86 mg/kg. Sodium and potassium were reported as 2.23 – 4.47 mg/kg and 1.41 – 3.62 mg/kg respectively. Other results reported includes; Nitrogen (2.52 - 4.63 mg/kg), Organic carbon (7.78 - 10.51 mg/kg), Carbon-Nitrogen (2.23 - 3.51 mg/kg), Total Hydrocarbon Content as in THC (4.96 - 9.62 mg/kg). Also on a general note, other parameters monitored were moderate, while electrical conductivity (EC) and all nutrients (Calcium, Magnesium, Sodium, Potassium, Nitrite, Nitrate, Sulphate and Phosphate), were higher in the Dry season. Our findings revealed mild anthropogenic activities within the Orashi River. We therefore call on all stake holders and inhabitants around the River Orashi to desist from anthropogenic activities that could infringe on biodiversity or public health.