Occurrence and distribution of monocyclic aromatic hydrocarbons (BTEX) and the impact on macrobenthic community structure in Lagos lagoon, Nigeria

Abstract

The widespread distribution of petroleum products arising from the rapid growth of the petroleum industry in Nigeria has resulted in the pollution of the environment through oil spills involving leakages from tankers, pipelines, tank farms, and dumping of waste petroleum products. The impacts and distribution of major toxic components (benzene, toluene, ethylbenzene, and xylene (BTEX)) of petroleum products in water and sediment samples collected from sampling stations in the Lagos lagoon was investigated over a 2-year period (February 2009-July 2010). The distribution of benthic communities in the different sampling stations of the Lagos lagoon was assessed. The determination of hydrocarbon levels in the samples showed that the levels of total hydrocarbon content (THC) in the water samples around the Atlas Cove and Apapa were high with values ranging from 2.03 to 31.38 mg/l and 4.04 to 22.89 mg/l, respectively. The highest value of total BTEX in the lagoon sediment was also recorded in the Apapa station (450.53 μg/kg), where oil depots and tank farm facilities are located. The study of the macrobenthic community structure showed that the species richness ranged from 1.57 to 2.02 in the reference station, Unilag, while in the Atlas Cove, Iddo, and Apapa stations, it ranged from 1.80 to 2.89, 1.95 to 3.03, and 1.86 to 2.95, respectively. The highest number of organisms (183) was recorded in the reference stations, while the least number (46) was recorded in Apapa. The main hydrocarbon pollution indicator species identified in the impacted aquatic stations were Nais eliguis and Heteromastus filiformis. The levels of hydrocarbon observed in the aquatic environment showed that there is widespread contamination as a result of petroleum product importation, storage, and distribution. The assessment of the monocyclic aromatic hydrocarbon and benthic community will therefore provide important tools for early detection, diagnosis, and management of hydrocarbon pollution in the Lagos lagoon.

Bioaccumulation of BTEX and PAHs in Heterotis niloticus (Actinopterygii) from the Epe Lagoon, Lagos, Nigeria

“…All these increase the concentration of these compounds in municipal waters, hence may explain the reason for the higher BTEX content in water over sediment. Doherty and Otitoloju [27] also reported higher total BTEX content in water in comparison with sediment from the Lagos lagoon. According to Fayemiwo [28], the occurrence of BTEX compounds in water is an alarming trend, especially in vulnerable parts of the world such as South-East Asia and Africa where these water bodies are directly relied upon for drinking and other potable uses.…”

Impacts of trace metals on African common toad, Amietophrynus regularis (Reuss, 1833) and depuration effects of the toad's enteric parasite, Amplicaecum africanum (Taylor, 1924) sampled within Lagos metropolis, Nigeria

“…The vegetation surrounding Lekki Lagoon is of the swampy mangrove type, predominated by Rhizophora racemosa and Avicenia nitida. Bioaccumulation of petrogenic pollutants have previously been reported at this location (Doherty et al, 2010;Doherty and Otitoloju, 2016;Akinsanya et al, 2018).…”

Spatial distribution of benthic foraminifera in the Lagos Lagoon (Nigeria): Tracing the impact of environmental perturbations

“…Ammonia aotena was found to be the dominant taxon along the highly polluted area north of Lagos Harbor (ST4), a finding that is concordance with the presence of living individuals from this area [7,8]. The area is impacted by highest concentrations of both carcinogenic polycyclic aromatic hydrocarbons (PAH), heavy metal pollutants, trichloroethylene and characterized by higher sediment oxygen demand (SOD) and total organic matter (TOM) levels in proximity to the heavily industrialized port area near Apapa [4,58,64,67]. Studies on the microbial assemblages indicated that the bacterial communities around this area differ substantially from non-polluted sites in the lagoon [58] and revealed lower diversity and evenness in the microbial communities.…”