"Acid rain poses a serious threat to wildlife that rely on aquatic ecosystems in eastern Canada, including many birds, mammals and amphibians. Studies conducted by the Canadian WiIdlife Service (CWS) since 1980 have shown that aquatic birds are adversely affected by acidity through a variety of ecological and ecotoxological processes that occur at lower trophic levels, but which may ultimately cause reproductive impairment and/or shifts in habitat selection or diet. The CWS LRTAP Biomonitoring Program was established in 1987 to verify the rate, nature and extent of biological recovery of aquatic ecosystems in eastern Canada following the implementation of acid rain control programs in Canada and the United States"--Abstract.