Depending on the air concentration, trees will absorb or release Hg. At low background concentrations, trees blow Hg into the air. At high backgrounds, trees absorb Hg from the air. Regardless of the background, forests become sinkholes for mercury due to the accumulation of decayed leaves and the wash from rain cascading down the trees. However, unlike other metals that constantly accumulate in forests, some Hg will be volatilized from the forest bed.
Lakes bioaccumulate differently.
The main determinate of bioaccumulation could be sulfur concentrations, but Lucotte does not say this. When Hg is found in aquatic wildlife, it is mostly in predatory fish. Lacustic Hg will decrease if the source is eliminated, such as in European lakes surrounding closed FSU facilities. In Canada, most soil Hg is in the top 5-10 cm of dirt. Most of this Hg is natural.