About This Project

Oysters are critical members of our coast, but today they live in more acidic environs thanks to increasing ocean carbon dioxide (CO2). Some marine microbes can combat acidity, and those microbes may be oysters' "secret weapons" in combatting the challenges of acidity. We will build a new sensor/sampler to gently "sip" water from inside oysters to measure microbial composition, chemistry, and acidity inside the oyster, and to see if/how the internal microbiome helps manage acidity.

Ask the Scientists

What is the context of this research?

Marine habitats are threatened by ocean acidification (OA) caused by increasing anthropogenic carbon dioxide that lowers seawater pH (i.e., it increases acidity). To preserve critical habitats, we need to understand how marine organisms cope with more acidity. In particular, calcifying organisms such as oysters that build shells can be seriously affected by acidity. Oysters are key members of their community, creating habitat and protecting from erosion. How they control pH is not fully understood, but there are hints that microbes bolster their resilience. I will use a novel sampler and sampler to collect seawater from within closed oysters at low tide (when they are most vulnerable), to study how the pH and chemistry changes and if/how the microbes help offset the higher acidity.

What is the significance of this project?

Oysters are critical members of many marine habitats. They 1) act as “ecosystem engineers” by creating habitat for other species, 2) improve water quality and enhance the health of bays and estuaries, and 3) create reefs that protect coasts from erosion.

Oysters need robust shells to live and build them by elevating the pH of their fluids. Interestingly, recent studies have shown that oyster fluids contains a diversity of microbes, some of which may contribute to maintaining the pH needed for shell growth. However, no study has looked at the temporal changes in microbial community composition and activity in living oysters, and so we lack the ability to discern if microbial composition and activity tracks with changing pH and, potentially, contributes to pH control and shell growth.

What are the goals of the project?

To see how the microbial community within an oyster changes over time, and if they influence internal pH, I will build a new sensor/sampler (based on my deep-sea microbial sampler) to collect fluids from within closed oysters. I will use small solenoid pumps to collect and preserve oyster fluid samples via a 0.8mm catheter tube, which will be adhered so the tubing can sample fluids within a closed oyster. 1 ml of fluid will be sampled hourly while the shell is closed, and preserved in RNALater(TM) for DNA & RNA within minutes. Another pump will sample/preserve for chemical analyses. Temperature will be logged by an iButton. Time series samples will be sequenced and compared to the chemistry & temperature data to begin understanding the microbial community’s role in pH management.