Current Work
Currently, I am a master's student at the Johnny Morris Institute of Fisheries, Wetlands and Aquatic Systems at the University of Missouri. I am investigating how environmental contaminants lead to transgenerational phenotypic responses and alter circadian regulation in Daphnia. More to come soon!
Previous work
Fluorine Free Firefighting Foams (F3s)
Fluorine Free Foams (F3s) are a class of formulated chemical products used to suppress fires. F3s have been recently developed to replace aqueous film forming foams (AFFF) due to concerns regarding PFAS content. While F3s are marketed as eco-friendly alternatives to AFFF, studies have shown F3s are just as, if not much more, toxic than AFFF. Despite these concerns, F3s are rapidly entering into large scale usage.
Evolved Effects in Daphnia magna
Breakdown of F3s
Following chronic exposure to sublethal doses of six F3s, heritable changes in tolerance were observed. Two F3s caused heritable increases in acute tolerance while one caused a decrease in acute tolerance. This work, published in Ecotoxicology, was the first to document effects of this kind in F3s. This work was also one of the first to document the effects long term exposure to these emerging contaminants.
Limited Effects on Hyla versicolor
Using the same chemical stocks, we conducted F3 acute toxicity testing using Daphnia magna in 2021, 2022, and 2024. We found that all six tested F3s saw statistically significant reductions in toxicity. The two tested F3s approved for US military usage, ECOPOL A and Avio, saw significant reductions in toxicity from 2021 to 2022 as well as from 2022 to 2024.
Reproductive effects on Pimephales promelas
This work observed the effects of chronic sublethal exposure on larval gray treefrog (Hyla versicolor) growth and development. This work, published in Environmental Toxicology and Chemistry, found that exposure to F3s had little effect.
This work observed the effects of chronic sublethal exposure on fathead minnow (Pimephales promelas) reproduction and gonad morphology. This work, in review at Environmental Toxicology and Chemistry, found that exposure to three of six F3s had effects on reproductive output or gonad size.
Evolutionary Consequences of Decades of PFAS Exposure
Historically, United States military sites frequently used AFFF in fire training exercises. Per and polyfluoroalkyl substances (PFAS) are key components of these AFFF formulations and often accumulate in aquatic ecosystems adjacent to application sites. We sampled Simocephalus serrulatus, a common species of zooplankton, from an ecosystem adjacent to a decommissioned Air Force base. In addition to being the first study to collect toxicity data on S. serrulatus, we found that individuals from that system were more sensitive to PFAS, impaired growth and development, yet reproduced more. This study, published in CLEAN – Soil, Air, Water, adds to the growing evidence of the compounding life history costs associated with multigenerational PFAS exposure.
