Standardization of Microplastics Sample Collection Methods Workshop

A closed, in-person workshop from March 8-9, 2023 to evaluate standard operating procedures for the collection of sediment, biological tissues, ambient water, and stormwater for microplastics analysis

Hosted by: Southern California Coastal Water Research Project Authority (SCCWRP)

In coordination with the California Ocean Protection Council and the California Water Resources Control Board

Evaluating Sample Collection Methods for Microplastics Analysis


The state of California has positioned itself as a world leader in addressing microplastic environmental contamination having adopted a technical definition for microplastics, standardized methods for laboratory sample processing and analysis, and a Statewide Microplastics Strategy. Each of these milestones represents a significant step toward a better understanding of the extent and magnitude of microplastic contamination and its potential impacts on human and environmental health.  

One of the central aims of the Statewide Microplastics Strategy is to build a statewide monitoring network for microplastics. While the aforementioned achievements are essential components of such a network, methods for the collection of microplastic samples have not yet been standardized. Standardization is essential prior to the launch of a statewide monitoring network as different sampling approaches may have significant effects on the data collected and their interpretation. For instance, comparisons between results from bulk water collection (e.g., grab samples) and towed nets (e.g., manta trawling) often vastly differ in the amount of water sampled and the types of microplastic particles that are captured, and efforts to align these data lead to huge estimates of uncertainty.  

The primary goal of this project is to generate standardized sample collection methods for monitoring microplastics in ambient water, stormwater, sediment, and biota. This goal will be achieved through a three-step process:  

  1. Convene a workshop to identify which methods are ready for evaluation and develop a study design to capture method performance  
  2. Implement the sample collection method evaluation study designed during the workshop  
  3. Use the results of the method evaluation study to refine sample collection methods and generate formal guidance documents, including standard operating procedures, for the collection of microplastics samples from the four matrices of interest 
Video recordingPresentation
Video recordingOcean Protection Council perspective (Kalua)
California Water Board perspective (Coffin)
Informing water sampling (Rochman)
Microplastics monitoring in streamflow (Gray)
Sediment collection methods for microplastics (Ho)
Sampling biological tissues (Brander)
Understanding method performance for monitoring microplastics (Thornton Hampton)