Oral Presentation Society for Freshwater Science 2025 Annual Meeting

Utilizing American Bullfrog (Lithobates catesbeianus) tadpoles to Assess Uptake and Depuration of Tire Wear Particles. (117599)

Beija K Gore 1 , Austin D Gray, Ph.D. 1
  1. Virginia Tech, Blacksburg, Virginia, United States

Microplastics are recognized globally as toxicological agents due to their physical and chemical properties threatening biota. However, a type of microplastic that has gained attention is particles from the wear of tires called Tire Wear Particles (TWP). TWPs are captured during storm run-off events and accumulate in retention ponds where non-targeted organisms can reside. TWPs occurrence in ponds presents various questions. Can early-stage organisms consume TWPs when exposed, and if so, do these particles accumulate within various organs or compartments of the organism? If TWPs are accumulating within their body, what are the rates at which TWPs are being uptake and removed? In our study, American Bullfrog (Lithobates catesbeianus) tadpoles were used to evaluate the uptake and depuration rates of TWPs. We tracked TWPs in tadpoles by exposing them to a concentration of 20mg/L 96 hours, where every 24 hours, we tracked TWP accumulation in gills, liver, GI tract, and whole body. Following uptake, we moved to select tadpoles to particle-free water to track depuration from target organs and the body of the tadpoles. We found the average rates of TWP uptake for gills, livers, and GI tract were 0.32 ± .17, 0.53 ± 0.34, and 4.78 ± 0.93 per hour; in comparison, full body uptake rates were 5.63 ± 1.39 particles per hour. The average rates of particles removed during depuration for gills, livers, and GI tract were -0.34 ± 0.12, -.09 ± 0.03, and -4.1779 ± 1.36 per hour; in comparison, full body depuration removal rates were -0.86 ± 2.14 particles per hour. Our findings demonstrate that early-stage tadpoles can accumulate and remove TWPs when exposed, with noticeable accumulation in organs that influence immune function. Thus, warranting research into the physiological impacts of association with exposure to TWPs, which may result in disruption to tadpoles biological processes.