We probably don't need more studies. We know what to do. Right now, particularly in the north, we're seeing increasing levels not from the hydroelectric dams, but just from the active emissions of mercury from coal plants and other things.
The hydroelectric situation is somewhat distinct, in that there is a large amount of mercury initially, and then over time it declines. Hydro-Québec does a lot of research into that and have shown that over time it's declining.