Application of correlation analysis in assessment of
relationships between mineral hydrocarbon levels and
hydrocarbonoclastic bacteria count in tropical
mangrove estuarine sediments
Pearson’s Product-Moment correlation analysis of the relationships between total hydrocarbon content (THC)
and hydrocarbon utilizing bacteria population (HUB) in mangrove sediments and overlying water of the Qua
Iboe Estuary, Nigeria was carried out. The results show that there was in general a close relationship between
the two variables, but also a large amount of variation not explained by the analysis. The strongest positive
relationships (p = 0.05) were found for THC in epipellic (intertidal) sediment and water (r = 0.65) while the
relationship between THC in benthic (subtidal) sediment and water (r = 0.028) was weak, and positively
insignificant (p = 0.05). A correlation of HUB densities on THC in benthic sediment was strong and positive (r =
0.91) but characterized by high HUB/HET ratios. That is, the strength of the relationship with respect to the oil
degrading potentials of the bacterial was fairly low. In contrast, the relationships between the two variables in
epipellic sediment (r = 0.66) was positively significant (p = 0.05) but with a substantial presence of heterotrophic
bacteria. This implies that a quick-analysis of hydrocarbon content in epipellic sediment in relation to
hydrocarbon utilizing bacteria densities following an oil spill is reliable. However, such analysis on benthic
sediment may not be reliable in estuarine environment with chronic exposure to crude oil pollution. This is
despite the wide distribution of HUB (82.4% in benthic sediment, 43.1% in epipellic sediment, and 33.3% in
surface water) in the ecosystem as revealed by the coefficient of determinations (R2) values