A Screening-Level Ecological Risk Assessment for Microplastics in Seafood in American Samoa
A beach with palm trees, littered with debris.
A pilot study in 2015 revealed high accumulations of shoreline debris at Nu'uuli Lagoon on American Samoa. (Photo Credit: Arizona State University)

Researchers from Arizona State University are using a risk assessment framework to quantify microplastics in water, sediment, and bivalves at three sites in American Samoa, as well as assess the types and concentrations of organic contaminants in the water, sediment, bivalve and microplastic samples.

Type of Project: Research

Region: Pacific Islands

Project Dates: August 2017 – July 2019

Who is involved?
Researchers from Arizona State University, with support from a NOAA Marine Debris Program Research grant, are working with partners from the American Samoa Environmental Protection Agency and Department of Marine and Wildlife Resources in American Samoa to collect and analyze microplastics and contaminants in water, sediment, and bivalve samples.

What is the project and why is it important?
In recent years, research has shown that bivalves can filter microplastic particles out of the water. However, there is limited field data on the concentrations and types of microplastics ingested by these animals or on the effects of microplastic ingestion (to both the bivalves and to the humans potentially eating the bivalves). The Marine Debris Program of the American Samoa Environmental Protection Agency has thus prioritized microplastics monitoring, research, and risk assessment within their 2016-2018 strategic objectives.

In this field study, researchers are collecting samples of water, sediment, bivalves, and market fishes to determine microplastic concentrations in these samples and to analyze them for organic contaminants. These researchers are also comparing the concentrations of organic contaminants in the water, sediments, and seafood samples with the concentrations found attached to the microplastics. Using this information, they are estimating the toxicological impacts of microplastic and organic contaminant pollution on locally-consumed seafood in order to characterize the potential ecological risk to marine ecosystems and health risks to human populations in American Samoa.

This study is working to fill a critical research gap in quantifying bivalve uptake of microplastics and organic contaminants under complex environmental conditions. Results may inform ongoing environmental regulation, educational outreach, and marine conservation efforts in American Samoa. As bivalves and locally-caught fishes are an important source of protein for other populations around the world, this study is also providing a framework for scientific or regulatory agencies working in similar, data-poor regions, to conduct screening-level risk assessments using in-situ, baseline studies at the local or regional scale. Additionally, this project includes extensive participatory training, education, and capacity-building opportunities for local researchers, community fishers, and community college students in American Samoa. These collaborations not only strengthen local career opportunities and skill sets, but also increase community awareness and action to reduce marine debris and other pollutants in near-shore coastal ecosystems.