Seasonal and Trophic Dynamics of Microplastic Bioaccumulation in Copepods and Jellyfish of Matagorda Bay, Texas

Microplastic (MP) bioaccumulation and biomagnification in marine food webs remains poorly understood, specifically trophic transfer from primary consumers to higher trophic levels. Although MP transfer has been studied in various organisms including fish, crustaceans, and gelatinous zooplankton, most existing research relies on short-term laboratory studies or simple field investigations lacking data on seasonal variations. This study fills that gap by tracking MP ingestion and transfer over time, across spatial gradients, and among developmental stages in Matagorda Bay, Texas. Field-collected samples of the copepod Acartia tonsa and the jellyfish Stomolophus meleagris were examined and laboratory exposures to assess MP body burden, survival, and morphological effects were conducted. Seasonal differences in MP concentrations and ingestion patterns were observed, with higher MP burdens correlating with rainfall and runoff. Laboratory exposures revealed increased MP accumulation in both copepods and jellyfish, along with a significant reduction in jellyfish bell diameter over time. The findings revealed notable trends in seasonal variation, species-specific MP uptake, and potential sublethal impacts on zooplankton and gelatinous predators. This study advances overall understanding of MP trophic dynamics in estuarine food webs and verifies the need for temporally resolved multi-trophic assessments. The findings contribute to and necessitate further long-term, multi-trophic monitoring to inform mitigation strategies for MP contamination in coastal ecosystems.