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

Number of schools
16
14
12
10
8
6
4
2
0
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12:00
Time
FIGURE 51. — Number of Chinook salmon schools observed on June 16, 2004 between 0600 h and 1200 h at
McClellan Pier, Lake Washington.
At McClellan Pier, Chinook salmon were observed moving along the shore in both a
northerly and southerly direction. In 2003, we observed 64% of the schools moving in a
northerly direction; whereas, in 2004 we observed 85% moving north. Combined (2003 and
2004), 47% of the schools were small (0 to 50 fish), 36% were medium-sized (50 to100 fish),
16% were large (100-200 fish) and 1% were very large schools (> 200 fish).
As Chinook salmon approached McClellan Pier they were typically in water that was 1.5
to 2 m deep (Figure 52) and 12 to15 m from the shore. When they got to within 3 to 4 m of the
pier, they swam to deeper water and usually swam under the pier where the water depth was
about 2.1 to 4.5 m deep. On a few rare occasions, fish did not go under the pier but headed into
deeper waters and appear to turn around and head in the opposite direction. After most fish
swam under the pier, they usually swam back towards shore and returned to the same depth as
they were before encountering the pier. On some occasions, Chinook salmon continued to move
to deeper water after they past under the pier. We could not tell if they eventually returned to the
shoreline.
85