Tracking the impacts of nutrient inputs on estuary ecosystem function

This work investigated a novel combination of techniques to rapidly assess sewage pollution in an estuarine environment. We used a novel combination of stable isotope analysis, assessment of benthic macroinvertebrate communities, and 16S rDNA genotyping of benthic microbial communities. Stable nitrogen isotope analysis identified multiple treated and untreated sewage inputs as the dominant nutrient source at specific locations. The benthic macroinvertebrate community reflected these inputs with significant increases in polychaete density at some sites. Microbial community composition and predicted function also reflected sewage inputs, particularly within sediments, and we identified a number of microbial taxa with relative abundances linked to sewage inputs.