Mercury (Hg) emission regulations in the US have resulted in clear declines in Hg concentrations in air and precipitation across the Great Lake Basin, however, less clear trends in fish Hg are evident (Monson, 2009). Various environmental stressors, including aquatic invasive species, may increase bioavailability of legacy Hg in lake sediment. Zebra mussels (Dreissena polymorpha) shunt energy resources from the water column to the littoral zone. Methylmercury (MeHg), the most bioaccumulative form of Hg, enters the aquatic food web in these regions. Walleye (Sander vitreus) and yellow perch (Perca flavescens) rely on pelagic energy, which is depleted during zebra mussel invasion. Post invasion, walleye and yellow perch shift energy reliance to littoral areas, increasing exposure to MeHg. Data were collected from 12 zebra mussel invaded and 9 uninvaded Minnesota lakes. Total Hg concentrations were analyzed using a hieratical Bayesian model. δ13C and δ15N isotope ratios were used to quantify littoral energy reliance using Bayesian mixing models. Walleye and yellow perch of average length contained 72% (16%-135%) and 159% (90%-250%) more Hg in lakes invaded with zebra mussels, respectively. Similarly, fish relied on littoral energy sources 35%-111% more in lakes invaded with zebra mussels. A state Hg standard of 0.22ppm establishes safe fish consumption guidelines. Walleye reached the threshold at 72% smaller lengths in invaded systems. An average-sized walleye (419mm) crossed the threshold 98% of the time in zebra mussel lakes compared to 17% in uninvaded systems. Zebra mussels induce significant aquatic food web changes that increase Hg concentration in walleye and yellow perch. Since walleye and yellow perch are popular for consumption, natural resource managers need to be aware of the prevalence of zebra mussels and the important role they may have in exacerbating Hg in fisheries as well as management decisions for public health.