Effect of weir impoundments on methane dynamics in a river.

We measured CH concentration, CH oxidation in the water column and total CH emissions to the atmosphere (diffusion and ebullition) in three weir impoundments and river reaches between them, in order to understand their role in river methane (CH) dynamics. Sediment samples were also collected to determine CH consumption and production potentials together with the contribution of individual methanogenic pathways. The CH surface water concentration increased 7.