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

Fry emerge from their redds from January to March. Juvenile Chinook salmon
appear to have two rearing strategies: rear in the river and then emigrate in May or June
as pre-smolts, or emigrate as fry in January, February, or March and rear in the south end
of Lake Washington or Lake Sammamish for three to five months. Juvenile Chinook
salmon are released from the Issaquah State Hatchery in May or early June and large
numbers enter Lake Sammamish a few hours after release (B. Footen, Muckleshoot
Indian Tribe, personal communication). Juveniles migrate past the Chittenden Locks
from May to August with peak migration occurring in June. Juveniles migrate to the
ocean in their first year, and thus Lake Washington Chinook salmon are considered
“ocean-type” fish.
Besides Chinook salmon, anadromous salmonids in the Lake Washington basin
includes sockeye salmon (O. nerka), coho salmon (O. kisutch), and steelhead (O. mykiss)
Sockeye salmon are by far the most abundant anadromous salmonid in the basin. Adult
returns in excess of 350,000 fish have occurred in some years. In comparison to other
similar-sized basins in the Pacific Northwest, the Lake Washington basin is inhabited by
a relatively large number of fish species. Besides anadromous salmonids, there are 22
extant native species of fishes in the Lake Washington basin. An additional 27-28
species have been introduced, 20 of which are extant.
In addition to the lentic systems of the Lake Washington basin, we also examined
the habitat use of Chinook salmon in Lake Quinault, a natural 1,510 ha lake located in
north Grays Harbor County, Washington and part of the Quinault Indian Reservation.
The lake is approximately 6.3 km miles long and its outlet is at river kilometer 53.7 on
the Quinault River. The mean depth is 40.5 m and the maximum depth of the lake is
approximately 73 m deep. Similar to Lake Washington, Lake Quinault has steep-sloping
sides and an extensive, flat profundal zone. Some recreational and residential
development has occurred on the shores of Lake Quinault but the level of development is
minimal in comparison to Lake Washington and Lake Sammamish. Very little of the
shoreline of Lake Quinault is armored and few docks are present. Besides the Quinault
River and its tributaries, Chinook salmon have also been observed spawning in Canoe
Creek, Zeigler Creek, Gatton Creek, Falls Creek, and Willaby Creek. Preliminary
information suggests that Chinook salmon fry enter Lake Quinault later in the year than
in Lake Washington, probably due to the colder water temperatures of the Quinault River
and other natal tributaries and thus the incubation time is longer. The average
escapement for the past ten years of adult Chinook salmon above Lake Quinault is
approximately 1,500 fish. Juvenile Chinook salmon in Lake Quinault may also come
from the Quinault Indian Nation hatchery located on Lake Quinault. Approximately
300,000 to 400,000 fish are released annually. Because they are released in late summer,
they would not be present when we conducted our surveys in April and June. Besides
Chinook salmon, Lake Quinault is also an important nursery area for coho salmon and
sockeye salmon. Unlike Lake Washington, few introduced fish species are present in
Lake Quinault. The only introduced species we observed was common carp (Cyprinus
carpio).
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