Sadie Libal is from Two Harbors, MN, and defended her Environmental Studies masters thesis at Bemidji State University during the summer of 2017. Her project looked at mercury accumulation in aquatic tree swallow food web of Grand Portage National Monument and how surface water sulfate concentration influences Hg accumulation. Mercury accumulation in Grand Portage was similar to other national parks in the region and sulfate concentrations were highest in the bog and deep marsh and the remaining wetlands had significantly lower and less variable sulfate concentrations.
