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Gurdon Times - Gurdon, AR
  • Arkansas Game and Fish Commission report on the studies on mercury loadings of fish

  • A study last year showed the mercury loadings of fish in certain areas of the Lower Ouachita River System are high and fish from those areas exceed levels that are safe for consumption.

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  • A study last year showed the mercury loadings of fish in certain areas of the Lower Ouachita River System are high and fish from those areas exceed levels that are safe for consumption.
    Eric Brinkman, Fisheries Supervisor with the Arkansas Game and Fish Commission’s Camden Regional Office, presented a report on the studies on mercury loadings of fish in the Lower Ouachita River System during a recent meeting with the Ouachita River Commission.
    Periodic evaluations have been done since mercury was discovered in the waters in the early 1990s.
    In 1992, mercury levels in fish of the Lower Ouachita River were discovered to exceed human consumption recommendations.
    From 1992 through 1994, the Task Force sampled more than 170 lakes and streams across the state. Their findings revealed that the problem was not limited to the Ouachita River or the Gulf Costal Plain. However, the OR region appeared to be impacted more than any other region in the state.
    According to the results released by the Game and Fish, 164 largemouth bass were collected and analyzed for total mercury content. Of that sampling, 89 fish were taken from the Felsenthal Reservoir, 25 from the Camden Pool, 25 from the Thatcher Pool and 25 from the Lower Saline River.
    In his report, Brinkman noted there are two particularly alarming facts about the data collected in 2010.
    “Fish within Felsenthal Reservoir now exceed ADH action levels at 12 and 13 inches total making most harvestable-sized fish unsafe to consume regulary,” Brinkman’s report said.
    Tests will also be done on 10 and 11-inch fish to determine if they are safe for consumption.
    “The second alarming piece of information is the magnitude with which fish collected in the Saline River System exceed the mercury advisory,” said Brinkman.
    Future studies should examine if specific tributaries of the Saline River are contributing large amounts of mercury to the system, according to information from the Game and Fish.
    According to the analysis, fish in the Felsenthal Reservoir, near Ashley and Union Counties, that are two years old or more exceed the Arkansas Department of Health mercury advisory level while none from the Camden Pool did.
    Analysis between data indicated that mercury levels in 2010 were statistically different than they were in 1995.
    Comparisons of mean mercury levels by inch group indicated that 12 and 13-inch largemouth bass exceeded mercury advisory levels in Felsenthal Reservoir in 2010.
    Fish collected in the main channel of the Ouachita River had higher levels of mercury than fish collected on the west side of the reservoir, according to the report. Data was not available for the east side of Felsenthal Reservoir.
    For the largemouth bass collected in the Felsenthal Reservoir, age was the only factor that was significantly correlated to mercury levels.
    Brinkman concluded his report by making the following recommendations:
    Page 2 of 2 - • 13 inch minimum length limit for largemouth bass be evaluated from Tate’s Bluff, in Ouachita County, to Felsenthal Lock and Dam, including the lower Saline River downstream of Stillion Bridge in Ashley County.
    • Encourage Arkansas Department of Health to reword mercury advisories for the Lower Ouachita and Saline Rivers and continue to inform the public about the risks of consuming excess mercury.
    • Reevaluate mercury levels of other recreational and commercially important fish species of the Lower Ouachita River System in the near future.
    • Establish a periodic sampling regime to track changes in mercury levels of fish populations with known mercury contaminations through time.
    • Determine which tributaries of the Saline River are contributing large amounts of mercury to the system.
    • Evaluate the mercury levels in largemouth bass smaller than 12 inches.
     

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