Updated (2022) Conceptual Model for an Ecological Risk Assessment for Microplastics on Striped Bass in the Potomac River Estuary

Description

Plastic trash and its breakdown products are found in many terrestrial and aquatic habitats including fresh, estuarine, and marine waters. These plastics typically occur as the result of two broad sources-- primary and secondary plastics. The ecological risk of these plastics, specifically those in the size range of microplastics and nanoplastics, is largely unknown. However, these are size ranges known or expected to be ingested or taken in through gills of aquatic organisms. The purpose of this project is to expand upon the needs identified in the Microplastics Expert Workshop Report (USEPA 2017) and develop a preliminary conceptual ecological risk assessment model to identify pathways, sources, effects and unknowns related to environmental plastic debris, specifically microplastics and smaller, in the tidal portion of the Potomac River. The Potomac is a major tributary to the Chesapeake Bay, and this conceptual risk assessment will serve as a starting point for understanding the potential ecological effects of microplastics on the aquatic resources in the larger Bay. This initial effort is expected to inform a science strategy for microplastics in the Potomac River and provide insights regarding restoration efforts around the Chesapeake Bay and contributing watersheds, a need outlined recently by the Chesapeake Bay Program (Murphy et al. 2019).

The first version of this report was published in February 2021.