In-situ microplastic egestion efficiency of the eastern oyster Crassostrea virginica. (May 2022) - Craig, Casey A.
Abstract: Microplastics (MP) are a pervasive environmental pollutant that enter coastal water bodies, posing an ingestion risk to marine biota. This study quantified the ability of the Eastern oyster ( Crassostrea virginica ) to egest MP in-situ in their biodeposits - feces and pseudofeces. Oysters of all sizes were able to egest environmental MP at a mean rate of 1 MP per 1 h through feces, and 1 MP per 2 h through pseudofeces. Smaller C . virginica were more efficient at egesting MP, and efficiency decreased by 0.8% per 1-g increase in tissue weight, with C . virginica of harvestable size being much less efficient. These findings are of relevance to resource managers for C . virginica populations as it further contributes to our understanding of MP accumulation in wild populations and has implications for not just C . virginica but also for their consumers. Highlights: Microplastic (MP) egestion efficiency of Crassostrea virginica was investigated using an in-situ biodeposition apparatus. Fibers were the most abundant MP and polyethylene terephthalate was the most abundant polymer, in biodeposits and oysters. MP were present in both feces and pseudofeces and excreted at a rate of 1 MP per hour and 1 MP per 2 hours, respectively. Oysters had a mean egestion efficiency of 62.1% during 2-h trials. This contributes to our understanding of MP accumulation in C . virginica and is of relevance to managers of wild populations.