When scientists recently set out to look for fish tainted by mercury, they found concentrations in every fish they sampled. For this study, scientists pulled over 2000 fish randomly from 626 rivers in 12 western states. Some of these fish, especially fish who eat other fish, had very high levels of mercury, while other had no more than what you would find in tuna fish used for canning. Scientists speculate that these mercury levels could originate from industrial pollution, old mercury mines, or even from the atmosphere in the form of precipitation.
While mercury levels in some fish were very high, they do not pose a threat to humans, but could affect other wildlife who eat these tainted fish
Source: Environmental News Network, Survey Finds Mercury in Fish in West, by Jeff Barnard, January 24.
