Bioaccumulation of Total Hydrocarbon Content by Three Mangrove Species (Rhizophora, Laguncularia, Avicennia) in the Niger Delta, Nigeria

Abstract

Bioaccumulation of total hydrocarbon content (THC) in mangrove is a bottom up effect. Leave, root, seed and stem samples were collected from red, black and white mangroves from highly and lowly polluted locations. Total hydrocarbon analysis was done with atomic absorption spectrophotometric method using HARCH DR 890 colorimeter (wavelength~420 nm). The result indicates that there is significant difference in THC between species (F2, 105=9.82, P seed>root>stem. For red mangroves THC ranged from 0.47 mg/l in root to 25.38 mg/l in the leave, for white mangroves THC ranged from 1.08 mg/l in stem to 5.90 mg/l in leave; for black mangrove THC ranged from 1.08 mg/l in stem to 21.64 mg/l in seed in the lowly polluted location while in the highly polluted location for red mangroves THC varied from 1.08 mg/l in stem to 23.97 mg/l in leave, for white mangroves THC varied from 0.64 mg/l in stem to 4.32 mg/l in leave and for black THC varied from 1.31 mg/l to 6.17 mg/l in leave. Mangrove parts in lowly polluted location had higher mean THC (10.43 ± 1.74 mg/l) than plant parts in highly polluted location (5.21 ± 0.62 mg/l). This study implies that red mangroves are good pollutant sink, which makes them a good bioremediation agent. Contamination of mangrove can lead to biomagnification of hydrocarbon up the food chain.