Record Details
Point and nonpoint source mercury pollution of Oregon Reservoirs
ScholarsArchive at Oregon State University
| Field | Value |
|---|---|
| Title | Point and nonpoint source mercury pollution of Oregon Reservoirs |
| Names |
Park, Jeong-Gue
(creator) Curtis, Lawrence R. (advisor) |
| Date Issued | 1996-03-07 (iso8601) |
| Note | Graduation date: 1996 |
| Abstract | Two Oregon reservoirs contaminated by different mercury sources were compared for mercury distribution in sediment and bioaccumulation by fish. The average mercury concentration in the sediment of Cottage Grove reservoir (0.67 ± 0.05 μg/g dry wt) was higher than for Dorena Reservoir (0.12 ± 0.01 μg/g dry wt). Sediment mercury in the main tributary of Cottage Grove Reservoir, which drains the tailing of past mercury mining activities, was ten fold higher than mercury in sediment from other reservoir tributaries with no evidence of mining. However, there were no significant differences between sediment mercury concentrations in the tributaries of the Dorena Reservoir, which has no mercury mining history within its watershed. Three fish species (largemouth bass, bluegill, crappie) from Cottage Grove Reservoir had significantly higher levels of mercury than the same species from Dorena Reservoir. These results indicated that a point source, Black Butte Mine, contributed amounts of mercury in excess of natural deposits based on differences in bioaccumulation among fish populations from these two systems. Cottage Grove Reservoir was examined for environmental evidence of point source mercury pollution. High mercury concentrations were found at various points around the suspected source, the Black Butte Mine area. The highest concentration occurred close to the kiln. The mercury concentration in the sediments of a creek below the mine dump was up to ten times higher than that of the sediments of a creek from a watershed adjacent to the watershed of the mine area. Two sediment cores from the deep area were collected to assess for pollution history profiles. These showed mercury loading in Cottage Grove Reservoir was consistent with the past mercury production in Black Butte Mine. Therefore most of mercury in Cottage Grove Reservoir was believed to be of Black Butte Mine origin. Mercury contents in pore water and food web indicated that continuing mercury transportation from the point source create a management problem in Cottage Grove Reservoir. |
| Genre | Thesis/Dissertation |
| Topic | Mercury -- Environmental aspects -- Oregon -- Cottage Grove Lake |
| Identifier | http://hdl.handle.net/1957/34612 |
