Concurrent Session: Wetland challenges
10:45 AM - 12:00 PM Wed
Co-authors: Sadie O'Dell, Sarah Warner, and Jon Krapfl, USFWS; M. Elsbeth McPhee, UW-Oshkosh
Title: Risk assessment of heavy metals in sediment, root, and mammal tissue at Horicon Marsh National Wildlife Refuge
Abstract: Heavy metal and metalloid pollution is an important area of study given these elements' high toxicity, persistence in the environment, and bioaccumulation potential. Wetlands are resilient to these pollutants, with the ability to sequester and transform them to more innocuous forms, but are also vulnerable over critical thresholds. We conducted a survey for seven heavy metals (cadmium, chromium, copper, nickel, mercury, lead, zinc) and one metalloid (arsenic) in sediment, roots of the invasive hybrid cattail (Typha x glauca), and livers from muskrats (Ondatra zibethicus) at Horicon National Wildlife Refuge (HNWR). Our primary goal was to evaluate risk to the refuge for management purposes and assess for any change since the last survey on the refuge was conducted in 1990 (sediment only). In addition, we were interested in investigating the potential of Typha x glauca to sequester metals and metalloids in their roots, as this plant is a strong competitor and could alter metal cycling in dynamics. It could also serve as a part of a trophic transfer pathway for herbivores that feed on it such as muskrats. Upon comparison to literature values and thresholds, we concluded that heavy metals and metalloids pose a low risk to the refuge. Sediment concentrations are similar to or lower than concentrations measured in 1990, which may be a result of natural or anthropogenic causes. Hybrid cattail may be a source of metals and metalloids in muskrat tissues, however, at the levels observed at HNWR, there is minimal risk to muskrats. We recommend that our results be used as a "healthy" point of comparison for others conducting metal and metalloid surveys on wetlands.
Bio: Sarah Woody graduated from Lawrence University in 2019 with a bachelor's degree in biology. After completing a 1-year fellowship in the animal welfare science department at Lincoln Park Zoo, she is now investigating the role of contaminants in wetland health through her thesis research at the UW-Oshkosh.