|"The Fish Journal"
Issaquah Press, Published April 20, 2010
By Dallas Cross
the direction of the Washington Department of Fish and Wildlife, the
efforts of the Lake Sammamish Kokanee Work Group to increase dwindling
kokanee salmon numbers in Lake Sammamish are now underway.
salmon have been entwined within the history and culture of native and
immigrant residents of Lake Sammamish since the Ice Ages. See a
previous Fish Journal piece, “Tribal Tales of the Kokanee Trout Clan,” published in The Issaquah Press and on the Web here. (FishJournal.org)
Kokanee Work Group is comprised of state, county and city municipal
officials, conservation organizations, and individuals from King County
and surrounding communities. All are highly motivated to save the late
run species of native kokanee from an extinction experience similar to
that of the early run kokanee in Issaquah Creek.
winter, fish biologists captured male and female Lake Sammamish kokanee
returning to several tributary creeks. More than 34,000 eggs were
harvested, fertilized with milt from males and placed in incubation
trays at the Cedar River and Chambers Creek state fish hatcheries. On
March 25, the first native kokanee fry raised by the Chambers Creek
fish hatchery were released in Ebright, Laughing Jacobs and Lewis
creeks. They immediately migrated to Lake Sammamish. A second release
in the same streams was performed on April 14 with fry raised by the
Cedar River Hatchery.
the lake, the kokanee will mature and return to spawn within three to
four years. Observations of progress and measurement of success will be
culminated when mature hatchery fish return to tributary creeks to
spawn and are captured for examination.
do they expect to identify the returning adult kokanee from natives in
the lake, distinguish fish from the two hatcheries and know in what
creek they were released as fry? The answer is exactly the same as how
merchants keep track of their inventory. They use bar codes.
biologists have found that small changes of water temperature in which
kokanee fry are raised result in changes in tiny bones in the inner ear
of the fish. These changes appear as visible bands on the bones that
persist throughout the life of the kokanee. By changing the water
temperature in the hatcheries, they have created different patterns of
bands on the ear bones, or otoliths, that will identify adult hatchery
kokanee, thus revealing their stream and hatchery origins and their
the hatchery kokanee return to the creeks where they were planted? What
is their survival rate? Will they stay in Lake Sammamish? Can a program
to supplement kokanee with hatchery-raised fish bring their numbers
back to levels where they can be fished again? All are questions hoping
for positive answers.
Now, information from spawning hatchery kokanee, obtained by scanning their built in bar codes, will help with these answers.