Establishing guideline values for copper toxicity to marine microbial communities

Understanding the rapid responses of marine microbiomes to environmental disturbances is paramount for supporting early assessments of harm to high value ecosystems such as coral reefs. Yet, management guidelines aimed at protecting aquatic life from environmental pollution remain exclusively defined for organisms at higher trophic levels. The primary objective of this study was to apply established ecotoxicology principals to 16S rRNA gene amplicon sequencing data to provide ecotoxicological toxicity thresholds for the reference pollutant copper (Cu) on the composition of seawater microbiomes. The new approaches employed here provide opportunities to quantitatively assess the effects of copper on microbial communities towards the inclusion of prokaryotes in future water quality guidelines.