Microbial pollution disables the chemical defenses of sea fans

In coastal ecosystems chemically rich species like gorgonians rely on specialized metabolites and symbiotic microbes for health and defense. The loss of chemical defense has never been reported in the marine environment. We investigated whether pollution-driven stress could lead to a dysfunctional holobiont and impairment of its chemical defense. Using UHPLC-HRMS/MS and molecular networking we profiled secondary metabolites and used 16S rRNA gene amplicon sequencing to characterize microbial communities, relating these data to visual surveys of Phyllogorgia dilatata gorgonian forests.