title: Extreme precipitation appears a key driver of mercury transport from the watershed to Cottage Grove Reservoir, Oregon.
abstract: An abandoned cinnabar mining and roasting site is in the major sub-basin of the watershed for Cottage Grove Reservoir, Oregon. Average surface sediment total mercury concentration in the river draining this sub-basin (0.61 ± 0.52 μg/g) was about ten-fold higher than three smaller tributaries to the reservoir. Total mercury in reservoir surface sediments averaged 1.66 ± 0.70 μg/g. Stratigraphy for two sediment cores indicated generally decreased reservoir mercury loading from 1963 to 2002 but two pronounced peaks in mercury deposition. Years of extreme precipitation immediately prior to these peaks at least partially explained them. Epaxial muscle total mercury concentrations of largemouth bass increased with body weight up to 2.5 μg/g. A gradient of mercury concentrations in soils from a 3.3 km diameter grid indicated condensation of mercury vapors from the mine site polluted the sub-basin.
authors: Department of Environmental and Molecular Toxicology, Oregon State University, Corvallis, OR, USA. larry.curtis@oregonstate.edu
authors: Lawrence R
authors: LR
authors: Curtis
authors: Donna L
authors: DL
authors: Morgans
authors: Bryn
authors: B
authors: Thoms
authors: Daniel
authors: D
authors: Villenueve
mesh_terms: D004784:Environmental Monitoring; D005618:Fresh Water / Q000737:chemistry*; D019015:Geologic Sediments / Q000737:chemistry; D008628:Mercury / Q000032:analysis*; D017669:Mercury Compounds; D008906:Mining; D008956:Models, Chemical; D009922:Oregon; D011891:Rain / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000032:analysis*; D014877:Water Pollution, Chemical / Q000706:statistics & numerical data
chemical_list: D017669:Mercury Compounds; D014874:Water Pollutants, Chemical; D008628:Mercury; C034211:cinnabar