Nearshore Habitat Use by Juvenile Chinook Salmon in Lentic ...

FIGURE 43.—Photo of a group of juvenile Chinook salmon within a overhanging vegetation/small woody debris
(OHV/SWD) structure, March 27, 2003. Within this structure, Chinook salmon were more closely associated with
the OHV.
Discussion
A variety of different surveys from Lake Washington, Lake Sammamish, and Lake
Quinault have indicated that overhead cover (alone or in combination with small woody debris)
is an important habitat feature for small Chinook salmon. In March 2001, small Chinook salmon
were often found under south Lake Washington docks during the day (Tabor and Piaskowski
2002). No SWD was present under these docks. Surveys of natural OHV/SWD sites in Lake
Washington and Lake Sammamish found large numbers of small Chinook salmon were often
present (Tabor and Piaskowski 2002; Tabor et al. 2004b). In Lake Quinault, we also found
Chinook salmon directly under LWD and OHV. In 2004, we undertook a field experiment to
test its importance, and results clearly showed that large numbers of Chinook salmon use sites
with overhead cover. Use of overhead cover by juvenile Chinook salmon has also been observed
in Cedar River (R. Peters, USFWS, unpublished data). Brusven et al. (1986) used an artificial
stream channel to test the importance of overhead cover and found it was an important habitat
component for juvenile Chinook salmon. Meehan et al. (1987) covered sections of a sidechannel
of the South Fork Salmon River and found the number of juvenile Chinook salmon was
substantially higher in the covered sections than open sections.
The use of overhead cover has also been documented for other juvenile salmonids.
Juvenile Atlantic salmon preferred overhead cover when light levels were greater than 300 ft-c
(Gibson and Keenleyside 1966). Fausch (1993) found juvenile steelhead selected habitat
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