You are here:
Microplastics in marine sediments: A comparison of current extraction and isolation methods
Citation:
Cashman, M., K. Ho, S. Russo, S. Robinson, T. Boving, AND R. Burgess. Microplastics in marine sediments: A comparison of current extraction and isolation methods. Society of Environmental Toxicology and Chemistry North America (SETAC NA) 39th Annual Meeting, Sacramento, CA, November 04 - 08, 2018.
Impact/Purpose:
Mircoplastics, or small (<5 millimeter) pieces of plastic are polluting marine environments. Many researchers have shown that there is substantial microplastic pollution in marine sediments, but scientists do not know their ultimate abundance or expanse. There are many existing methods for quantifying microplastics in marine sediments, but procedural differences make it difficult to compare results from one method to another. This research compares five current microplastic extraction methods for their ability to recover a variety of different microplastics from marine sediments. The results are of interest to managers and scientists in Regions, States, Tribes and Programmatic Offices as they make decisions on the best methods to extract, isolate and identify microplastics.
Description:
Despite frequent field observations of microplastics (plastic particles <5mm in size) there is a critical knowledge gap of their fate and effects in marine and estuarine environments. Relative to fate, much of the microplastics will ultimately accumulate in marine sediments as a result of physicochemical and biological processes. Many methods exist for the extraction and isolation of microplastics from marine sediments, but major procedural differences prevent meaningful comparison among methods. These differences may result in altered recoveries of varying polymer types, sizes, and shapes present in environmental samples. The goal of this research was to conduct a systematic assessment and intercomparison of five commonly used methods for microplastic isolation and identification in representative marine sediments. Methods were selected to reflect the range of procedures in the scientific literature. Each method was reviewed for its applicability in two sediment types (sandy and silty) as well as evaluated on their ability to recover microplastics amended into sediment samples. The microplastics chosen include a range of polymers, sizes, and shapes that are commonly identified in published field surveys. The research allows for quantification of the performance of the five methods, as well as provides initial recommendations for routine microplastic monitoring procedures in marine sediments.