200 Microplastics in the Environment

Microplastics are becoming increasingly ubiquitous on Earth. This session aims to address: sources and distribution of microplastics globally, characterization and quantification of microplastic hazards and impacts throughout the microplastic life cycle, and mitigation of microplastics-induced health effects

Tuesday, 21 October 2025
1:30 PM - 5:30 PM
HBGCC, 213AB

Leaky Lagoons and Sticky Shorelines: Searching for Microplastics in Coastal Environments

Paper number: 200-8
Program: Technical Sessions
Time: 3:20 PM – 3:35 PM

Authors

  • William Bailey Presenting Author
    University of Texas at Austin - Jackson School of Geosciences, Austin, TX
  • David Mohrig
    The University of Texas at Austin, Jackson School of Geosciences, Austin, TX
  • Cornel Olariu
    University of Texas at Austin, Jackson School of Geosciences, Austin, TX
  • Kutalmis Saylam
    University of Texas at Austin, Bureau of Economic Geology, Austin, Texas

Abstract

Plastic pollution is ubiquitous to coastal environments, where future sea level rise and increasing storm frequency pose significant threats of bringing man-made waste materials closer to growing coastal populations. This research first analyzed microplastic concentrations in Texas bays sediments, thinking these known sediment traps host microplastic hotspots. Rather, a key finding from this study is relatively low microplastic concentrations, and larger microplastic particles consistently deposited with finer sediment grain sizes suggesting preferential remobilization of microplastics particles. Storm events are proposed to govern the lack of microplastics in bay sediment as they constitute periods in which materials (sediment, plastics) are rapidly introduced into the water column and transported through the system. The fate of this suspended debris after storms is poorly constrained. Our research targets the fate of flotsam (debris washed onto land) after hurricanes to assess how storms affect plastic transport and deposition along the Texas Gulf coast. Using remotely sensed data (UAV-drone, airborne lidar) coupled with field measurements, this research revealed storm surge overtopping the Matagorda barrier island and flooding the East Matagorda Bay, followed by significant outwash. Aeolian dune topography and vegetation of the barrier preferentially trapped marine litter within highwater deposits. However, new washover fans indicate large quantities of debris was transported to the back-barrier and bay and new washout channels exported material to the Gulf of Mexico. Given the ability of storms to erode material from bays and barriers, the Gulf of Mexico is likely the ultimate fate for coastal pollutants.

Geological Society of America Abstracts with Programs. Vol. 57, No. 6

doi: 10.1130/abs/2025AM-411945

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