Bulk precipitation provided some 29% of the required in the ecosystem to balance net biomass storage plus streamwater loss before the mid-1950s; however, from 1955 to 1975, bulk precipitation input decreased to meet only 8% of the total demand, while net soil release increased to 77%.
Metals such as mercury and cadmium from soil deposits in lakes, streams, and reservoirs can accumulate in the tissues of fish, making them toxic to humans.