Climate change is altering the coastal environments and contributing to the increased emergence and spread of infectious diseases, including Vibrio. Vibrio species are some of the most significant environmental human pathogens that originate from aquatic and marine environments. They are principal pathogens of marine organisms, including fish, bivalves, shrimps, and corals. In natural environments, Vibrio exists in heterogeneous microbial communities and can be concentrated in filter-feeding shellfish, such as oysters and clams, that can function as a vector of transmission. The long-term goal of the research program is to understand how signaling mechanisms enable multi-species bacteria to coordinate behaviors for adaptation, competition, and survival under climate change scenarios and how these interactions affect oyster host microbiome and colonization. Our research focuses on two Vibrio species, Vibrio vulnificus (Vv) and V. parahaemolyticus (Vp), in aggregates (marine snow) and host-associated conditions (oysters) to determine the stress response adaptations. The over-arching questions for this research project are: 1) How do changes in environmental conditions alter Vibrio abundance, signaling, and gene expression in different climate change scenarios?, 2) How does the oyster microbiome composition (species diversity and abundance) change under climate change conditions?, and 3) What is the impact of climate change on Vibrio-host colonization? The results of these experiments will provide the basic mechanistic link involved in the adaptation and host-colonization of multi-species Vibrio communities and the impacts of climate change on them. By examining these interactions, better models can be developed to respond to the effects of climate change on critical food chain sources and risks of Vibrio colonization and pathogenicity.