Study Finds Mercury in Many Western Fish

An Oregon State University and U.S. Environmental Protection Agency study has shown widespread mercury concentrations in fish.

The fish were taken from more than 600 rivers and streams across 12 western U.S. states. Although few of the more than 2,700 fish analyzed contained alarmingly high levels of mercury, scientists say the prevalence of the element surprised them.

Mercury is everywhere, said Associate Professor Alan Herlihy, one of the authors of the study. It was literally in every fish we sampled, which suggests an atmospheric source.

The researchers found mercury levels were much higher in larger fish-eating species, including bass, walleye, northern pike and pikeminnow.

The researchers noted the risk for humans who may occasionally eat fish from the streams is fairly low, although infants, young children, pregnant women and people who eat a lot of fish have higher risk levels than the general population.

Results of the study were published earlier this month in the journal Environmental Science and Technology.