Activities of hydrocarbon-utilizing and diazotrophic bacteria in crude oil impacted mangrove sediments of the Qua Iboe Estuary, Nigeria

Analysis of the total petroleum hydrocarbons (TPH) and the activities of hydrocarbon-utilizing bacteria (HUB) and diazotrophic bacteria (DB) in mangrove sediments of the Qua Iboe Estuary revealed that the organic-laden sediments have high hydrocarbon repository status. The epipelic sediment was relatively richer in total organic nitrogen (TON) content. Correlation analysis revealed positive relationship between TPH and HUB (r = 0.60) in the epipelic sediment, while no definite relationship (r = − 0.30) was established between the variables in benthic sediment. A strong negative relationship was observed between TPH and TON in the intertidal (r = − 0.746) and benthic (r = − 0.838) sediments. However, weak positive (r = 0.451) relations were established between TPH and log-transformed densities of DB in both the epipelic and benthic sediment. These indicate that although hydrocarbons contamination may have a direct negative effect on nitrogen availability in mangrove sediment, it has variable influence on t...