An investigation into the bacterial communities present at two estuarine beaches in the South Hams, Devon, UK: the effects of oil pollution

Abstract

Aims: To determine if there are any differences between oil-degrading:heterotroph ratios and bacterial communities from a polluted and non-polluted site. Methods and Results: Composite samples for both water and sediment were collected from Mothecombe (polluted) and Wembury (control). Cultural enumeration and molecular analysis was performed to determine any differences between bacterial communities. No differences were observed between the bacterial communities of the two sites. Sediment samples were an order of magnitude higher in abundance compared to water samples. Conclusion: Mothecombe appears to have recovered from oil pollution. Culture-independent studies are needed to clarify the validity of these findings. Significance and Impact of study: This paper stresses the importance of avoiding culture-dependent methods to analyse bacterial communities. The application of ODB as indicators of oil-pollution is important, but careful consideration should be applied when selecting a control site. Previous oil pollution could increase a sites tolerance and ability to biodegrade oil due to an increase in bacterial community diversity. Direct analysis of the community, via molecular methods, is required to verify is this hypothesis is correct.