Impacts of Lime Treatment on Trout Ponds in the Five Ponds Wilderness of the Adirondack Park

Addition of calcium carbonate (CaCO3) to lakes in the form of agricultural limestone is a management technique used in the Adirondack Park in New York State to mitigate the effects of acidic precipitation on aquatic ecosystems. We used a combination of in situ and laboratory experiments as well as field sampling of two neighboring ponds in the Five Ponds Wilderness with different liming histories to test whether the application of limestone can have significant effects on survivorship and community composition of aquatic organisms. Within in situ mesocosms or laboratory microcosms survivorship was decreased for crustacean zooplankton, amphipods and odonata nymphs at concentrations of one ton per surface acre of lime and higher; the New York State Department of Environmental Conservation (NYSDEC) applies lime at one ton per surface acre. Tamarack Pond has been managed by lime addition and brook trout stocking and the aquatic insect community is significantly different than that of Slender Pond, which has never been limed or stocked, even though the two ponds share a water source. This difference may be attributable to predation impacts of fish on aquatic insects, making the link between liming and insect faunal compositions difficult to determine. This study suggests the short term impacts of lime treatment on biota may affect the biotic community of aquatic ecosystems on a longer time scale, and may need to be considered before a liming program is started. Including the volume of a body of water to be limed when determining lime additions would be an inexpensive way to limit the impact that treatment would have on the aquatic ecosystems of the Adirondack Park