Pathogens

It is well known that pathogens, such as SARS-CoV-2 (COVID-19), Vibrio spp., Salmonella spp., Shigella spp., E. coli, Streptococcus spp. and Giardia spp., are found in wastewater (Bogler et al., 2020; Chahal et al., 2016). Since many of these pathogens can infect animal species besides humans, researchers are now investigating whether wastewater containing these pathogens can affect habitat-forming species on coral reefs. One recent study has experimentally confirmed that this can occur. Researchers in the Florida Keys found that increased occurrence of white pox disease in elkhorn coral — a dominant habitat-forming species in the region — was associated with wastewater exposure. A sampling of coral tissue infected with the disease revealed high concentrations of the opportunistic human-associated pathogen Serratia marcescens, while subsequent experiments using Koch’s postulates determined that S. marcescens does cause white pox disease in elkhorn coral (Patterson et al., 2022; Sutherland et al., 2011). Since a severe die-off event of elkhorn coral in the Florida Keys was attributed to white pox disease, poor wastewater management has been implicated as an important driver of coral loss in the region. Yet for such a significant event, there is little awareness or acknowledgement of wastewater pollution as a potential driver of this loss. As this field of study expands, it is likely that more research will show that pathogens in wastewater can infect and kill marine organisms.