Estimating Methylmercury Injury to Birds—“The Bird Mercury Tool”
U.S. Geological Survey (USGS) scientists have developed a tool that can be used by practitioners to help interpret injury to birds caused by methylmercury contamination. This tool was developed from a comprehensive review of 168 studies and summarizing data on the effects of methylmercury on birds.
Inorganic mercury (Hg) contamination has global environmental effects. Once in the environment, bacteria (in soils and water) transform inorganic mercury into methylmercury (MeHg), which bioaccumulates and poses a significant risk to fish and wildlife health. Bioaccumulation of methylmercury occurs in aquatic and terrestrial food webs; therefore, higher trophic level predators, such as birds, are commonly exposed to elevated MeHg concentrations. Deleterious effects caused from MeHg in birds have been documented and include overall health, reproduction, and survival.
Federal and State regulatory agencies set toxicity standards for protecting wildlife, evaluate risk by screening animals in contaminated areas, assign potential injury to wildlife, and mitigate or restore contaminated habitats. However, there was not a generalized toxicity reference value for the effect of MeHg on birds that could be effectively used for injury assessments caused by environmental contamination.
USGS scientists conducted a comprehensive review of the published literature, summarized the available data, and performed a series of meta-analyses to derive new toxicity reference values for the effects of MeHg on birds. This study statistically estimated the necessary toxicity reference values by integrating all data for the effect of Hg on birds using robust mathematical models. Lethal and sublethal effects of Hg on birds were assessed using six main endpoint categories: survival, offspring output, behavior, biochemical, histology, and body morphology. Impaired reproduction is the most common toxicity endpoint for birds; therefore, scientists also developed three combined endpoint categories with input from experts and practitioners within the U.S. Department of the Interior’s Natural Resource Damage Assessment and Restoration program: combined reproduction endpoints, combined survival and reproduction endpoints, and all endpoints during the breeding season.
These new toxicity reference values were then used to develop a software tool that can be used by practitioners to more easily estimate injury to birds caused by Hg pollution.
This research was supported by the USGS Ecosystems Mission Area, through the Environmental Health Program (Contaminant Biology and Toxic Substances Hydrology); and the U.S. Department of the Interior, Office of Restoration and Damage Assessment.
Click here to access the "Bird Mercury Tool"
U.S. Geological Survey (USGS) scientists have developed a tool that can be used by practitioners to help interpret injury to birds caused by methylmercury contamination. This tool was developed from a comprehensive review of 168 studies and summarizing data on the effects of methylmercury on birds.
Inorganic mercury (Hg) contamination has global environmental effects. Once in the environment, bacteria (in soils and water) transform inorganic mercury into methylmercury (MeHg), which bioaccumulates and poses a significant risk to fish and wildlife health. Bioaccumulation of methylmercury occurs in aquatic and terrestrial food webs; therefore, higher trophic level predators, such as birds, are commonly exposed to elevated MeHg concentrations. Deleterious effects caused from MeHg in birds have been documented and include overall health, reproduction, and survival.
Federal and State regulatory agencies set toxicity standards for protecting wildlife, evaluate risk by screening animals in contaminated areas, assign potential injury to wildlife, and mitigate or restore contaminated habitats. However, there was not a generalized toxicity reference value for the effect of MeHg on birds that could be effectively used for injury assessments caused by environmental contamination.
USGS scientists conducted a comprehensive review of the published literature, summarized the available data, and performed a series of meta-analyses to derive new toxicity reference values for the effects of MeHg on birds. This study statistically estimated the necessary toxicity reference values by integrating all data for the effect of Hg on birds using robust mathematical models. Lethal and sublethal effects of Hg on birds were assessed using six main endpoint categories: survival, offspring output, behavior, biochemical, histology, and body morphology. Impaired reproduction is the most common toxicity endpoint for birds; therefore, scientists also developed three combined endpoint categories with input from experts and practitioners within the U.S. Department of the Interior’s Natural Resource Damage Assessment and Restoration program: combined reproduction endpoints, combined survival and reproduction endpoints, and all endpoints during the breeding season.
These new toxicity reference values were then used to develop a software tool that can be used by practitioners to more easily estimate injury to birds caused by Hg pollution.
This research was supported by the USGS Ecosystems Mission Area, through the Environmental Health Program (Contaminant Biology and Toxic Substances Hydrology); and the U.S. Department of the Interior, Office of Restoration and Damage Assessment.