Exploring changes in bacterial communities to assess the influence of fish farming on marine sediments

Changes in bacterial assemblages along an environmental gradient determined by the distance to aquaculture installations were analysed, using denaturing gradient gel electrophoresis to assess the influence of fish farming on marine sediments. Our findings show that changes in the structure of the bacterial community are a useful indicator for determining the environmental impact of aquaculture farms, due to the rapid response to changes in nutrient load, and could be an alternative strategy for monitoring programmes. Delta and Epsilonproteobacteria linked to the sulphur cycle were detected in the sediments beneath the cages. Since these groups were not found in the sediments at control stations, they serve as indicators for assessing the impact of the organic load from fish farming on marine sediments.