The bioaccumulation of metals, including mercury, arsenic, and selenium were measured in largemouth bass collected from Rogers Quarry. These samples were compared to bass taken from a uncontaminated quarry located on the Oak Ridge Reservation.
 | Selenium and mercury concentrations measured in largemouth bass in 1997 were two and ten times higher, respectively, than concentrations in bass from reference sites. Furthermore, mercury concentrations in bass exceed levels that are of concern for human consumption. |
| Selenium, a common constituent in fly ash, was highest in Rogers Quarry fish in the early 1990s, but gradually decreased since fly ash abatement (Figure 1). |
| Conversely, concentrations of mercury in fish rose sharply (Figure 2). The increase in mercury in fish may be due to: (1) the reduction in selenium inputs to the quarry (selenium is known to reduce mercury bioaccumulation), and (2) the chemical/ecological characteristics of the system which has resulted in an old, slow-growing largemouth bass population exposed to relatively high aqueous methylmercury concentrations. |
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Figure 1. Mean selenium concentrations (µg/g, wet wt.) in largemouth bass from Rogers Quarry, 1990-1998. |
| Figure 2. Mean mercury concentrations (µg/g, wet wt.) in largemouth bass from Roger's Quarry from 1990-1998, with and without adjustment for fish weight. |
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Last Modified: April 17, 2001