MERCURY BIOACCUMULATION IN SPOTTED SALAMANDERS IN SOUTHWEST OHIO

Mercury (Hg) is a volatile element that is increasing in concentration in the environment as a result of anthropogenic emissions. Microorganisms, such as sulfate-reducing bacteria, can transform mercury into methylmercury (MeHg), which bioaccumulates, biomagnifies, and can cause toxicity to humans and wildlife. Most studies of MeHg bioaccumulation have focused on aquatic organisms due to consumption of fish being the primary route of human exposure to MeHg. However, organisms in terrestrial ecosystems are also exposed to MeHg that may impact ecosystem biodiversity, food-web dynamics, and overall ecosystem health. We are investigating bioaccumulation and maternal transfer of MeHg in spotted salamanders (Ambystoma maculatum) captured from two locations in southwest Ohio in 2016. Total length, weight, sex, and whole-body concentrations of MeHg and total Hg are being determined in 159 individual salamanders. Moreover, we are developing a non-destructive sampling method for spotted salamanders by comparing MeHg concentrations in whole bodies with those in the tip of the organisms’ tails, which can regenerate. The results of this research will show how MeHg bioaccumulation in spotted salamanders may vary by sex, organism size, and among locations in southwest Ohio, and provide information about an understudied link in the terrestrial-aquatic food web.