About This Project

Eastern oyster, Crassostrea virginica, are a keystone species and a focal aquaculture species. These bivalves consume large amounts of microplastics (MP’s) as they filter surrounding waters for food. Microbes can colonize the surface of MP’s, including human pathogens of the genus Vibrio, which can then be transmitted to humans when oyster are consumed raw. This project aims to explore MP’s as a vector for human pathogens under projected climate change scenarios.

Ask the Scientists

What is the context of this research?

Eastern oyster are currently facing a suite of challenges. Changes in temperature, pH and salinity are negatively impacting their physiology and immune function, making them more susceptible to disease. Microplastics (MP’s) are now considered the most prevalent form of marine debris, and have been shown to impair oyster filtration efficiency and reproduction. Pathogenic bacteria (harmful to human; of the genus Vibrio) have been found on the “plastisphere”; the microbial community that forms on MP debris. Projected environmental scenarios model expansion of bacterial ranges. Oyster are becoming more susceptible to bacteria, which can colonize MP’s. Our project will explore if Vibrio can use microplastics as a vector to infect the Eastern Oyster, increasing human infection rates.

What is the significance of this project?

Given the important role oysters play both as a keystone species and as a focal aquaculture species, it is critical to explore how climate change projections impact the physiology of Crassostrea virginica; how these projections might influence microplastic (MP's) ingestion in this bivalve, and finally, if MP's serve as a disease vector for a known human pathogen. The answers to these questions will provide data on how Eastern oyster may fare in a projected estuarine environment, how MP's (specifically, monofilament fishing line and polyester/nylon threads) might impact their physiology, leading to impacts on oyster population numbers and finally, the suitability of oyster of a human food source under GCC scenarios with expanded bacterial ranges.

What are the goals of the project?

We will build on our pilot work exploring biofilm formation on microplastics (MP's). We will inoculate MP's with three strains of bacteria: Vibrio parahaemolyticus, V. vulnificus, and V. cholerae and measure biofilm formation at 3, 5 and 7-days to discern the idealized incubation time.

These Vibrio-colonized MP’s will then be added to our experimental system. Oyster are housed in a series of tanks mimicking projected environmental scenarios of the year 2300. We are currently exploring the interaction of elevated temperature (20°C to 27°C) and ocean acidification (400µatm to 2000µatm). At 7, 14, and 28-days of exposure, oyster will be removed from the system, hemolymph extracted, and microplastic counts of ingested particles will be performed.