Risks from mercury in anadromous fish collected from Penobscot River, Maine
Safety of human and wildlife consumers is paramount. To that end, levels of mercury were measured in tissue of six species of migratory fish (Alewife, American Shad, Blueback Herring, Rainbow Smelt, Striped Bass, and Sea Lamprey), as well as, in the roe of American Shad for two consecutive years (2017 and 2018). The resultant mercury levels were compared to reference doses as established in the U.S. Integrated Risk Information System (IRIS) and wildlife values. Mercury concentrations ranged from 4 µg/kg in roe to 1040 µg/kg in Sea Lamprey. Sea Lamprey contained the highest amounts of mercury for both seasons of sampling. Current health advisories are set at sufficient levels to protect fishermen from harmful consumption of the fish, except for Sea Lamprey. Based upon wildlife values for Mink, Otter, and Eagle, consumption of Rainbow Smelt, Striped Bass, or Sea Lamprey pose a risk to Mink; Striped Bass and Sea Lamprey to Otter; and Sea Lamprey to Eagle. The resultant data can serve to inform the review or development of water quality standards that are protective of sustenance fishing. U.S. EPA works with Tribes across the nation greatly impacted by restrictions on sustenance fishing, to develop culturally sensitive risk assessments.