153MERCURY DEPOSITION IN NINE DESIGNATED FEATHER REGIONS Mercury deposition in nine designated feather regions of eight captive raised, dose response Common Loons (Gavia immer)

The presence of methylmercury in natural environments is on the rise due to an increase in atmospheric mercury deposition rates. Piscivorous wildlife is at high risk due to the toxic effects of methylmercury bioaccumulation. Plumage develop-ment in birds has proven to be an elimination pathway for mercury, and may actually reduce total body mercury burdens. In this study, the elimination of methylmercury into nine designated feather regions was examined in eight captive raised, dose response Common Loons. These birds were divided into four dose treatment groups, were euthanized after 105 days, and their feathers were removed and analyzed for mercury content. Total mercury burdens were found to increase with an increased mercury dose, although variation in mercury content seen between feather regions could not be correlated with literature based molt sequence