Evidence for hyporheic transfer and removal of marine-derived nutrients in a sockeye stream in Southwest Alaska. In: Nutrients in salmonid ecosystems: Sustaining production and biodiversity

• Main Authors: Thomas C. O’keefe, Rick T. Edwards
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Published: 2003
• Subjects: Sockeye; Wood River; Alaska; Lynx
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.626.4277; http://riversandcreeks.com/research/publications/okeefe_edwards_2002.pdf

Abstract.—Evidence for the importance of marine-derived nutrient (MDN) inputs from spawning salmon to terrestrial and freshwater ecosystems is rapidly accumulating, but the mechanisms by which MDN inputs are transferred and stored within spawning streams and their catchments are poorly understood. Presumed marine isotope signals have been found in riparian vegetation, suggesting that marine nutrients may impact terrestrial plant communities. Studies have suggested that MDN increases stream productivity both im-mediately after spawning and during the following spring. The peak of many spawning runs occurs at the end of the summer growing season, suggesting that overwinter storage of MDN must be occurring. A potential location for lateral nutrient transfers and overwin-ter MDN storage is the hyporheic zone within stream channels or in adjacent riparian flood-plains. Within Lynx Creek, a sockeye-spawning stream in the Wood River Lake drainage in southwestern Alaska, extensive floodplain hyporheic zones occur along spawning reaches. Surface water moves into the floodplain hyporheic zone and flows downstream 70–80 m before returning to the stream. Ambient nutrient concentrations within the surface and hyporheic zone indicate that marine-derived nitrogen and phosphorus entered hyporheic