Abstract
Host-associated microbial communities are fundamental to host physiology, yet it is unclear how these communities will respond to environmental disturbances. Here, we disentangle the environment-linked and host-linked effects of ocean acidification on oyster-associated microbial communities. We exposed adult oysters (Crassostrea virginica) to CO2-induced ocean acidification (400 vs. 2800 ppm) for 80 d. We measured the oyster extrapallial fluid pH and sampled the gills for microbial analysis at six time points. We found that different subsets of microbes were linked to acidification (n = 34 amplicon sequence variants [ASVs]) and to host response (n = 20 ASVs) with little overlap (n = 8 ASVs), suggesting that some members of the oyster microbiome were more responsive to environmental conditions while others were more tightly linked to host condition. Our results provide insight into which members of the oyster microbiome may contribute to the health and resistance of their host, and which members are the most vulnerable to changing environmental conditions.
Scientific Significance Statement
Understanding microbial responses to environmental disturbances is critical. However, in host-associated microbial communities, it is unclear whether microbial response to disturbance is linked to the environment, or if it is mediated via host response. We used Eastern oysters as a model to demonstrate that both environment- and host-linked factors influence the composition and structure of gill microbial communities exposed to ocean acidification. Remarkably, members of the microbiome linked directly to elevated pCO2 were different from those linked to the host’s physiological response. Disentangling the microbial community’s response to environmental disturbance from its response to the host’s reaction to that disturbance is essential to understand and predict the effect of global change drivers on host-associated microbial communities.
Unzueta-Martínez A., Downey-Wall A. M., Cameron L. P., Ries J. B., Lotterhos K. E. & Bowen J. L., in press. Ocean acidification alters the diversity and structure of oyster associated microbial communities. Limnology Oceanography Letters. Article.
