Globally, methyl mercury continues to be a worrisome pollutant in aquatic ecosystems.   Although methyl mercury bioaccumulation studies abound in the literature, no such study exists for acid mine impacted waters.  Here we investigate methyl mercury bioaccumulation in some of the acid mine impacted streams that abound in southeast Ohio. Previous studies suggest that methyl mercury bioaccumulation is promoted by the low pH, elevated sulfate content and pockets of anoxia that are characteristic of acid mine impacted streams. We hypothesize that methyl mercury production and bioaccumulation is enhanced in southeast Ohio’s acid mine impacted streams. To investigate this hypothesis, we examined the impact of acid mine drainage on methyl mercury bioaccumulation in the crayfish (Orconectes sanbornii). We classified stream sites within the Sunday Creek Watershed as acid mine impacted and non-impacted sites and captured crayfish (18±3 mm orbital carapace length) from nine impacted and nine non-impacted sites. We shipped out the crayfish tail tissue for mercury speciation. Preliminary statistical analyses of the results show a negative correlation between methyl mercury content and severity of acid mine impact (r= 0.51). This discredits our earlier hypothesis but raises the question that why does methyl mercury bioaccumulation decrease with acid mine impact?