Scientists found that microbes and their genetic material from land-based sources of pollution could be found in reef water and in tissues of corals. This could affect the genomics of the native microbial communities found in coral reefs, which can impact how corals thrive and survive. These new insights highlight an additional potential threat to corals from land-based sources of pollution in southeast Florida, where corals are already under existential threat from warming oceans and resulting coral bleaching, disease and mortality.