Southeast Alaska Network freshwater water quality monitoring program: 2012 annual report

Sergeant, Christopher; Johnson, William

Freshwater water quality is an indicator of aquatic and terrestrial ecosystem health and one of twelve priority Vital Signs monitored in the National Park Service’s Southeast Alaska Network (SEAN). In 2012, hourly water temperature, specific conductance, dissolved oxygen, and pH data were collected in the Salmon River (Glacier Bay National Park and Preserve) from April 25 through October 31, and in the Indian River (Sitka National Historical Park) from April 30 through November 2. The same parameters plus turbidity were collected in the Taiya River (Klondike Gold Rush National Historical Park) from April 16 through November 19. Annual reports are concise data summaries that establish a regular and timely product for park staff, managers, superintendents, and other interested parties. This third annual water quality report from the SEAN represents the continuation of a long-term, high resolution water quality dataset in Southeast Alaska National Parks. All annual reports and data products are available at the SEAN freshwater water quality website: http://science.nature.nps.gov/im/units/sean/FQ_Main.aspx The Salmon and Indian Rivers demonstrated seasonal temperature trends generally similar to 2010 and 2011. 2012 daily mean water temperature in the Salmon River ranged from 2.0 to 9.8°C, peaking on August 7, while daily mean water temperature in the Indian River ranged from 2.5 to 8.7°C and peaked on August 23. Summer daily mean water temperatures in both rivers were slightly cooler than in previous years. Patterns in the medians and distributions of specific conductance, dissolved oxygen, and pH for each river were similar to previous years for each river. Due to the strong influence of glacial meltwater, the Taiya River had a lower median temperature than the mostly ground- and surface-water influenced Salmon and Indian Rivers. In 2012, daily mean water temperature ranged from 0.0 to 6.4°C, peaking on July 27. The ranges of seasonal values for specific conductance, dissolved oxygen, and pH were generally small. Turbidity ranged from 0 to 194 NTU and appeared synchronized with high flow events caused by heavy rain and glacial melt. No observed values or trends signaled point source pollution or a change to the fundamental water quality of the Salmon, Taiya, or Indian Rivers. Throughout the monitoring period, all three rivers exhibited water quality conditions within expected natural ranges.

Southeast Alaska Network freshwater water quality monitoring program: 2012 annual report

Series

Other versions

Collections