Application of correlation analysis in assessment ofudrelationships between mineral hydrocarbon levels andudhydrocarbonoclastic bacteria count in tropicaludmangrove estuarine sediments

摘要

Pearson’s Product-Moment correlation analysis of the relationships between total hydrocarbon content (THC)udand hydrocarbon utilizing bacteria population (HUB) in mangrove sediments and overlying water of the QuaudIboe Estuary, Nigeria was carried out. The results show that there was in general a close relationship betweenudthe two variables, but also a large amount of variation not explained by the analysis. The strongest positiveudrelationships (p = 0.05) were found for THC in epipellic (intertidal) sediment and water (r = 0.65) while theudrelationship between THC in benthic (subtidal) sediment and water (r = 0.028) was weak, and positivelyudinsignificant (p = 0.05). A correlation of HUB densities on THC in benthic sediment was strong and positive (r =ud0.91) but characterized by high HUB/HET ratios. That is, the strength of the relationship with respect to the oiluddegrading potentials of the bacterial was fairly low. In contrast, the relationships between the two variables inudepipellic sediment (r = 0.66) was positively significant (p = 0.05) but with a substantial presence of heterotrophicudbacteria. This implies that a quick-analysis of hydrocarbon content in epipellic sediment in relation toudhydrocarbon utilizing bacteria densities following an oil spill is reliable. However, such analysis on benthicudsediment may not be reliable in estuarine environment with chronic exposure to crude oil pollution. This isuddespite the wide distribution of HUB (82.4% in benthic sediment, 43.1% in epipellic sediment, and 33.3% inudsurface water) in the ecosystem as revealed by the coefficient of determinations (R2) values.