Trophic ecology and mercury bioaccumulation among Lake Superior lake charr (Salvelinus namaycush) ecotypes.

The Lake Superior lake charr population consists of siscowet, lean, humper and redfin ecological morphotypes or ecotypes. In addition to morphological and physiological differences, these fish occupy different habitats in Lake Superior and partition various invertebrate and fish prey resources. In this study, we measured the stable isotopes of carbon (δC) and nitrogen (δN) and mercury (Hg) concentrations among these ecotypes collected from the waters surrounding Lake Superior's Isle Royale.