Acadia National Park Water Monitoring 2006-2008

Gawley, William

In previous years, the goals, objectives, methods, and results of Acadia National Park (ANP) water monitoring programs were documented in program-specific reports. Significant changes in all aquatic monitoring programs occurred in 2006, which suggested taking a consolidated approach to reporting. Monthly field measurements and water samples were taken in twelve park lakes and eleven streams from May through October each year following "Vital Signs" monitoring protocols of the National Park Service (NPS) Inventory and Monitoring Program. Data from stream benthic macroinvertebrate monitoring and invasive aquatic plant monitoring, conducted in cooperation with the Maine Department of Environmental Protection (MDEP) and the Volunteer Lake Monitoring Program (VLMP) respectively, were also shared with the Vital Signs program. This integrated monitoring approach provides data for a variety of water quality parameters that can serve as indicators for the effects of atmospheric deposition, cultural eutrophication, and climate change. The monitoring data indicate that the lake Secchi transparency and water levels, and stream discharge were strongly influenced by seasonal precipitation trends. Dissolved oxygen, temperature, pH, acid neutralizing capacity, and nutrients appeared to be relatively stable, with concentrations generally within the historical range of variability for these water bodies, although a slight increase in nutrient levels and indicators of biological productivity became evident. Benthic macroinvertebrate data analysis indicated that all monitored streams retained their legislative classification, and no invasive aquatic plant species were encountered in any of the surveys over the three years. Although no statistical analyses were performed in this report to determine long-term data trends, an analysis of trends in lake water quality is expected to be completed by the NPS Northeast Regional Hydrologist by the time this report is available.