Methodology optimization to quantify microplastic presence in planktonic copepods, chaetognaths and fish larvae

Two of the groups most impacted by microplastics (MPs) are zooplankton and fish larvae, either through MPs ingestion or absorption. Although there has been an increase of studies focusing on MPs ingestion by these organisms, there is still no standardized methodology for the quantification of MPs present in plankton. For example, some reagents normally used to digest plankton and recover MPs appear adversely to affect some plastic characteristics. This can potentially lead to underestimating the amount and types of MPs present in the organisms analyzed. Hence, this work aimed to optimize a methodology to quantify MPs present in plankton, namely zooplankton and fish larvae, and ensuring MPs integrity. Hence, the planktonic organism tissues were digested using 30% (v/v) H(2)O(2) • A methodology was optimized to quantify microplastics present in zooplankton (copepods, chaetognaths and fish larvae). • Thirteen types of microplastics (fibers and fragments of different polymers) were used to test the efficiency of the methodology ensuring the maintenance of the integrity of plastics. • With this methodology, microplastic recovery was above 85% for all the types of microplastic tested and no changes in their characteristics were observed.