Studies in fish
Exposure to endocrine disrupting chemicals, at an early life stage can cause sex change in fishes, but little is known about how this influences population size or the overall fecundity of a population. We recently published work in Environmental Science and Technology describing how masculinization or feminization of group spawners such as Menidia species impacts overall reproductive output. In summation, we found that masculinization can be more detrimental than feminization.
In current work (2022-2025), silversides and other organisms are being exposed to micro and nanoplastics, and microfibers, in the lab to determine effects on gene expression, growth, and swimming behavior. This work is funded by an NSF Growing Convergence Research grant and other sources. Recent results demonstrate that silversides respond similarly at the molecular scale to nano-sized plastics of different types: tires, polylactic acid (bioplastic), and polyester fibers. Fibers appear to be more toxic, as has been shown in other studies.
Most recently (2025 onward), we are beginning a new study funded by Western Sustainable Agriculture Research and Education (WSARE) to evaluate the impacts of plastic mulch fragmentation on aquatic and terrestrial organisms, and crops too!
Studies in invertebrates
Current work (2022-2025) involves exposure of mysid shrimp, a common invertebrate prey item found in coastal areas globally, to micro and nanoplastics. We recently published on work showing that plastics of different polymer types and shapes, including fibers and fragments, cause reduced growth and changes in swimming behavior in these organisms.
We have also done research on pesticides in invertebrates. In 2017, we detected a byproduct of the insecticide fipronil in the eggs and ovaries of blue crab females (Callinectes sapidus) sampled from regional estuaries (Southeastern NC and Northeastern SC). In a follow-up study, naive juvenile crabs were exposed in the lab to fipronil and the detected byproduct, fipronil desulfinyl. Responses included altered growth and decreased expression of genes involved in growth and reproduction. This study was funded in part by North Carolina Sea Grant, a blog post about the research can be found here.
Ecotox and Environmental Stress Lab 