Microbial ecology
Microbial ecology is the study of interactions of
microorganisms with their environment, and investigates how they
carry out a diverse range of functions. Microorganisms play a
significant role in many ecosystem processes, including
the cycling of oxygen, carbon, nitrogen and sulphur. Bacteria
in particular channel energy within the pelagic and benthic
environment.
Through microbial ecology studies we are rapidly
gaining insights into the biogeography of marine
microorganisms, their community dynamics and response to natural
and man-made impacts. Recent findings confirm the importance of
microbial studies in developing indicators of impacts caused by a
variety of anthropogenic activities including eutrophication and
pollution. Investigating the structure and functional diversity of
microbial communities, their relationship to the environment and
other organisms holds promise as a potential tool to monitor
ecosystem health.
Vertical patterns in benthic microbial
diversity
We use a variety of fingerprinting techniques including RISA
(Ribosomal Intergenic Spacer Analysis) and DGGE (Denaturing
Gradient Gel Electrophoresis) to study the diversity of bacterial
and archaeal communities in pelagic and
benthic habitats. These are combined with multivariate statistics
to investigate the response of those communities to environmental
changes induced naturally or by human activity.
Specifically we are looking at the biogeography of benthic
microorganisms to understand the spatial variability of benthic
archaeal and bacterial communities and how this can be linked to a
variety of environmental parameters (biogeochemical
measures, the structure of macrofaunal communities). Greater
understanding of microbial responses to their abiotic and
biotic environments, as well as to temporal changes, is expected to
significantly improve future ecosystem-based evaluations.
We also look at the responses of microorganisms to human
pressures, like eutrophication. Our work could show differential
responses to eutrophication by bacterial communities, resulting in
marked community shifts along pollution gradients. Successfully
linking known or assumed impacts (such as eutrophication) to
microbial community shifts is expected to highlight their value in
evaluating and predicting pollution effects. 
nMDS plot based on Bray-Curtis similarities
of
bacterial communities
Generally, the ability to assess and predict the effects of
human activities against a background of natural change as required
by new legislation like the EU Marine Strategy Directive is largely
dependent on understanding and integrating the response of
organisms at all levels of organisation. Microbial communities can
indicate impact-induced changes within the pelagic and benthic
environment and show responses to environmental change.
For more information please email microbialecology@cefas.co.uk