Summary: Sediment Dynamics and the Hydromorphology of Fluvial Systems (Proceedings of a symposium held in
Dundee, UK, July 2006). IAHS Publ. 306, 2006.434
The importance of temporal changes in gravel-
stored fine sediment on habitat conditions in a
salmon spawning stream.
ELLEN L. PETTICREW* & JOHN F. REX
Geography Program, University of Northern British Columbia, 3333 University Way, Prince
George, British Columbia V2N 4Z9, Canada
Abstract Sediment (<2 mm and <75 Ám) was collected in a productive sockeye
spawning stream in northern British Columbia, Canada, using infiltration
gravel bags from the pre-spawn through to the post-spawning period of 2002.
As much of the gravel-stored fine sediment (<75 Ám) exists as larger,
aggregated particles composed of inorganic and organic matter, their quantity,
structure, composition and settling behaviour were assessed. The goal was to
evaluate the temporal changes in the gravel-stored fine sediment in the context
of: (a) fish activity (i.e. active spawning and die-off) and (b) inter-gravel
oxygen concentrations which reflect the habitat quality. Infiltration rates of
<2 mm sediment increased with stream discharge and fish redd construction.
The finer (<75 Ám) sediment exhibited lower infiltration rates during the peak