Ryan Lepak
The Association for the Sciences of Limnology and Oceanography recognizes a young scientist each year for leading an outstanding peer-reviewed, English-language paper in the aquatic sciences with the Raymond L. Lindeman Award. The 2021 Lindeman Award will be given to Ryan Lepak in recognition of the paper, “Mercury source changes and food web shifts alter contamination signatures of predatory fish from Lake Michigan,” published in Proceedings of the National Academy of Sciences of the United States of America. The award will be presented to Dr. Lepak, currently an NSF and EPA post-doctoral researcher in Duluth, Minnesota, USA, at the 2021 ASLO Aquatic Sciences Virtual Meeting in June.
In true spirit of the award’s namesake, Raymond L. Lindeman, this transformative paper was a direct result of Dr. Lepak’s dissertation work at the University of Wisconsin – Madison’s Environmental Chemistry and Technology program. Working alongside researchers at the USEPA and USGS Mercury Research Lab, Dr. Lepak utilized multi-isotope approaches to understand the changing sources and bioaccumulation of mercury in aquatic food webs over a 35-year archive of Lake Trout from Lake Michigan. The paper’s findings highlight the effectiveness of reducing regional mercury emissions to decrease mercury deposition to Lake Michigan thereby challenging the classic belief that mercury sources in the atmosphere are inherently global. The work reveals that food web changes resulting from invasive species can alter the flow of mercury within aquatic ecosystems and consequently the burden of mercury on fish. The results of this paper, and the innovative methods to determine mercury sources developed by Lepak and colleagues, will prove to be critical to better understanding the sources and dynamics of mercury in aquatic habitats and organisms.
“It is our pleasure to award Dr. Lepak the Lindeman early-career award for this outstanding paper,” said ASLO President Roxane Maranger. “His work will certainly have far reaching implications for assessing the combined influence of changes in contaminant source and concentrations as well as food web alterations in the study of mercury and other contaminants in aquatic ecosystems. We look forward with excitement to Dr. Lepak’s continued contributions to aquatic science!”
Full Citation: Lepak, R., J. Hoffman, S. Janssen, D. Krabbenhoft, J. Ogorek, J. DeWild, M. Tate, C. Babiarz, R. Yin, E. Murphy, D. Engstrom, and J. Hurley. 2019. Mercury source changes and food web shifts alter contamination signatures of predatory fish from Lake Michigan. Proceedings of the National Academy of Sciences 116(47): 23600-23608. https://doi.org/10.1073/pnas.1907484116