Glacier Bay National Park and Preserve oceanographic monitoring program: 2012 annual report
Sharman LC. 2017. Glacier Bay National Park and Preserve oceanographic monitoring program: 2012 annual report. Natural Resource Report. NPS/SEAN/NRR—2017/1461. National Park Service. Fort Collins, Colorado
The Southeast Alaska Inventory and Monitoring Network (SEAN) assumed responsibility from the U.S. Geological Survey for long-term oceanographic monitoring of Glacier Bay National Park and Preserve in 2009. This (2012) is the 20th consecutive year of the continuous dataset and is the fourth annual report. As operational conditions allowed, vertical profiles of temperature, salinity, light, turbidity, dissolved oxygen concentration, and chlorophyll fluorescence were obtained for the water column once in late winter and once in mid-summer at 22 permanent stations throughout Glacier Bay; eight of those stations were occupied monthly from March through October (2012 was the first full year in which Station 24 became a “core station” that was sampled during each survey). In general, parameters reflected typical ranges and spatial (both horizontal and vertical) and temporal trends expected for a high-latitude tidewater glacial fjord, with strong seasonal signals and strong length-of-fjord gradients along the glacier-to-bay mouth transects. The water column was well-mixed in winter and strongly stratified in summer. Fluorescence measurements indicated phytoplankton production occurred in surface waters from late spring through fall, presumably fueled by a near-continuous injection of nutrients to the euphotic zone by tidal, wind, and/or internal wave-induced mechanisms. Compared to historical data, the 2012 central bay water column in July was anomalously cool in the upper 30 m, anomalously fresh at 10-75 m, and anomalously low-density at 10-50 m. These anomalies generally resemble anomalies observed in mid-summer at similar depths at GAK1 in the northern Gulf of Alaska, and continue to highlight Glacier Bay’s inherent variability on inter-annual timescales. The 2012 sampling year marked the second with a dedicated survey vessel, as well as the second year of a three-year ocean acidification study that involves water sampling from discrete depths through the water column. It is expected that analyses of these samples (results reported elsewhere) will significantly enhance our understanding of Glacier Bay oceanography.
- Type
- Published Report
- Authors
- Sharman, Lewis
- Date of Issue
- 2017-06
- Publisher
- National Park Service
- Units
- GLBA , NRSS , SEAN
- Keywords
- Alaska, chlorophyll-a, CTD, fluorometer, Glacier Bay, Glacier Bay National Park, Glacier Bay National Park and Preserve, GLBA, Icy Strait, Monitoring, OBS, Oceans, PAR, photic depth, photosynthetically available radiation, physical oceanography, Pressure, Salinity, SEAN, sigma-t, Southeast Alaska Network, Temperature, Turbidity
- Subjects
- Ecological Framework: Water | Hydrology | Marine Hydrology