The findings suggest that nearly a year after the spill, the pyroplastics largely retained quantities and compositions of associated chemicals capable of eliciting bioactivity comparable to when the material first spilled. This outcome was not entirely unexpected given that polyethylene is used for the passive sampling of hydrophobic organic contaminants in the environment, i.e., partitioning between seawater and polyethylene skews toward greater amounts in polyethylene. With that in mind, the spilled plastic can accumulate and become enriched in additional contaminants from the environment. Continued monitoring of any uncollected plastic will be necessary to ascertain the extent to which its bioactivity profile and chemical complexity deviate from those when it first spilled over more extended periods in the environment.