Changes in aquatic microbial responses to C-substrates with stream water and sediment quality related to land use pressures.

The degradation of aquatic ecosystems by multiply-acting stressors is a key threat requiring new approaches to identify impairment processes and restoration targets. Heterotrophic respiration of C-substrates can be an integrative indicator of how aquatic ecosystems respond to pollution. We utilised sixteen C-substrates (simple metabolites to dissolved organic matter (DOM)) to characterise substrate induced respiration (SIR) for sediments from sixteen NE Scotland streams covering a range of land use-related pollution pressures.