Seasonal variability of fine-grained sediment morphology in a salmon-bearing stream.

Fine‐grained sediment in river systems: environmental significance and management issues

“…A study in O'Ne-eil Creek, a highly productive sockeye salmon stream in the northern interior of British Columbia (Petticrew and Droppo, 2000), found that the flocculated suspended sediment sizes changed over the season as the organic matter sources to the stream changed. Using stable isotopes of C and N, it was found that the organic component of the largest floc size, noted following the major salmon die-off, was composed predominantly of nutrients associated with salmon carcasses (McConnachie, 2003). A concurrent study found the size and density of the gravel-stored flocs ( Figure 5) was related to the presence of the fish detrital material (Petticrew and Arocena, 2003).…”

Tracing organic matter sources in riverine suspended sediment: Implications for fine sediment transfers

“…Morphological results for this same 2001 suspended sediment data set presented in McConnachie and Petticrew (2004) indicate that the largest aggregate particles (N 1000μm diameter), which exhibit the lowest densities and settling velocities, occurred predominantly in the spawn period and rain events during spawn. While these low density composite particles are likely to be maintained in suspension even in low flows, the denser, faster settling (N5mm s − 1 ) aggregates also found in the water column during active spawning may not be advected as far thereby returning to storage in, or on, the gravel surface over a short distance (McConnachie, 2003;Petticrew, 2005).…”

“…McConnachie, 2003) and the shear velocity (V ⁎ ; m s − 1 ) along a hydraulically rough streambed was determined using the methods of Gordon et al (1992). Bottom shear stress (τ 0 ; N m − 2 ) was calculated from data for each sample date as it is directly proportional to the square of the shear velocity and the density of water (ρ; kg m − 3 ), which is dependent on temperature (Nowell and Jumars, 1984).…”