Ecotoxicological Effects of Microplastic and Sorbed Priority Pollutants in Aquatic Foodchains

Mussels in a UC Davis laboratory receive polymers with PCBs.
Mussels in a UC Davis laboratory receive polymers with PCBs. Credit: Chelsea Rochman, UC Davis

Project Dates: August 2013 - July 2016

What is the project?

Researchers at the University of California, Davis, investigated the movement of contaminants associated with microplastics through aquatic food chains. In this study, different types of polymers (polyethylene terephthalate, polyethylene, polyvinyl chloride, and polystyrene) were spiked with polychlorinated biphenyls or “PCBs”, a group of manmade chemical compounds, and fed to mussels and freshwater clams. Understanding the impacts of PCBs is important because they are found in the marine environment and previous research has demonstrated their ability to sorb to plastic debris. The clams were then fed to sturgeon, mimicking a natural food chain in the San Francisco Bay Delta. Chemical analyses of animal tissues tracked PCB uptake to assess the degree of bio –accumulation and –magnification from each polymer type. The study also looked at impacts on the health and survival of the animals exposed to different types of microplastics with and without PCBs.

Who is involved?
This project took place at the Aquatic Health Program at the UC Davis Center School of Veterinary Medicine with funding from the NOAA Marine Debris Program research grant program.

What does it accomplish?
This project addressed key research questions about the relative impacts of different plastic types in transferring chemical contaminants to prey and predator species. It is known that many different species ingest microplastics in the lab and in nature, and that chemicals can be transferred from the plastic to the organism. This lab study looked at how higher trophic levels may be affected through eating prey species exposed to different types of plastics, and the impact of the plastics and contaminants on those animals.

What is something unique about the project?
In order to mimic the food source of bivalves in nature, the microplastics ingested by the clams and mussels had to be ground down to less than 0.5 mm.