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

Results
Seward Park, 2003.—In 2003, all six Seward Park sites were surveyed nine times
between February 19 and June 30. Combined, 171 juvenile Chinook salmon were
observed; over 45% (n = 79) were found at the west sites (sites 5 and 6). With the
exception of May 22, the west sites had the highest number of juveniles per 100 m on all
survey dates (Figure 16). Of the 79 Chinook salmon observed in the west sites, 59 were
present at site 5. A comparison between 2001, 2002 and 2003 for the months of April,
May, and June indicated the overall abundance of Chinook salmon was similar in 2001
and 2003 (except June) but the abundance in 2002 was substantially lower (Figure 17).
A total of 38 juvenile Chinook salmon (9 at site 3a and 29 at 3b) were observed at
the restoration site in 2003. Chinook salmon were observed at site 3b (small substrate)
on each survey in 2003 except June 30; although, on three dates only one Chinook
salmon was observed. At site 3a (large substrate), Chinook salmon were only observed
on four of nine survey dates and most Chinook salmon (78%) were observed on the last
three surveys which were after mid-May. Although Chinook salmon abundance was low
throughout 2003, there was a significantly more Chinook salmon at site 3b (small
substrate) than at site 3a (large substrate) (Wilcoxon sign rank test; Z = 2.4; P = 0.019).
Chinook/100 m
8
7
6
5
4
3
2
1
0
West
Northeast
Southeast
February 19
March 13
March 26
April 07
April 22
May 06
May 22
June 10
June 30
FIGURE 16.—Number of juvenile Chinook salmon (number/100 m) observed at night along three
shoreline areas of Seward Park, south Lake Washington, 2003.
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