[2] She did postdoctoral work with Richard Heinrich Rosenblatt at Scripps Institution of Oceanography[3][4] and David Hillis at the University of Texas at Austin.
[8] Stepien's research centers on the genetics and genomics of marine and freshwater fishes and invertebrates.
[12] She is interested in the population genetics and evolutionary patterns of invasive species, and has used genetic tools to study invasive species such as the zebra mussel and quagga mussel.
[18][19] She also is working with collaborators to apply eDNA biotechnology for monitoring and assessing marine and aquatic biological community dynamics using eDNA collected remotely from buoys, drones, AUVs, and gliders.
[1] In 2016, Stepien elected a fellow of the American Association for the Advancement of Science (AAAS) who cited her “for distinguished contributions to the fields of molecular evolutionary ecology and conservation genetics, particularly invasive and native populations, and mentorship of graduate and undergraduate students”.